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- -Often, apps need to interact with file systems, network interfaces, hardware, or timers. This chapter provides an overview of using async code in Dioxus.
-By default, Dioxus-Desktop ships with the Tokio runtime and automatically sets everything up for you. This is currently not configurable, though it would be easy to write an integration for Dioxus desktop that uses a different asynchronous runtime.
Dioxus is not currently thread-safe, so any async code you write does not need to be Send/Sync. That means that you can use non-thread-safe structures like Cell, Rc, and RefCell.
The use_future and use_coroutine hooks are useful if you want to unconditionally spawn the future. Sometimes, though, you'll want to only spawn a future in response to an event, such as a mouse click. For example, suppose you need to send a request when the user clicks a "log in" button. For this, you can use cx.spawn:
--#![allow(unused)] -fn main() { - let logged_in = use_state(cx, || false); - - let log_in = move |_| { - cx.spawn({ - let logged_in = logged_in.to_owned(); - - async move { - let resp = reqwest::Client::new() - .post("http://example.com/login") - .send() - .await; - - match resp { - Ok(_data) => { - println!("Login successful!"); - logged_in.set(true); - } - Err(_err) => { - println!( - "Login failed - you need a login server running on localhost:8080." - ) - } - } - } - }); - }; - - cx.render(rsx! { - button { - onclick: log_in, - "Login", - } - }) -} -
--Note:
-spawnwill always spawn a new future. You most likely don't want to call it on every render.
Calling spawn will give you a JoinHandle which lets you cancel or pause the future.
Sometimes, you might want to spawn a background task that needs multiple threads or talk to hardware that might block your app code. In these cases, we can directly spawn a Tokio task from our future. For Dioxus-Desktop, your task will be spawned onto Tokio's Multithreaded runtime:
-- --#![allow(unused)] -fn main() { - cx.spawn(async { - let _ = tokio::spawn(async {}).await; - - let _ = tokio::task::spawn_local(async { - // some !Send work - }) - .await; - }); -} -
Another tool in your async toolbox are coroutines. Coroutines are futures that can be manually stopped, started, paused, and resumed.
-Like regular futures, code in a coroutine will run until the next await point before yielding. This low-level control over asynchronous tasks is quite powerful, allowing for infinitely looping tasks like WebSocket polling, background timers, and other periodic actions.
use_coroutineThe use_coroutine hook allows you to create a coroutine. Most coroutines we write will be polling loops using async/await.
--#![allow(unused)] -fn main() { -fn app(cx: Scope) -> Element { - let ws: &UseCoroutine<()> = use_coroutine(cx, |rx| async move { - // Connect to some sort of service - let mut conn = connect_to_ws_server().await; - - // Wait for data on the service - while let Some(msg) = conn.next().await { - // handle messages - } - }); -} -} -
For many services, a simple async loop will handle the majority of use cases.
-However, if we want to temporarily disable the coroutine, we can "pause" it using the pause method, and "resume" it using the resume method:
--#![allow(unused)] -fn main() { -let sync: &UseCoroutine<()> = use_coroutine(cx, |rx| async move { - // code for syncing -}); - -if sync.is_running() { - cx.render(rsx!{ - button { - onclick: move |_| sync.pause(), - "Disable syncing" - } - }) -} else { - cx.render(rsx!{ - button { - onclick: move |_| sync.resume(), - "Enable syncing" - } - }) -} -} -
This pattern is where coroutines are extremely useful – instead of writing all the complicated logic for pausing our async tasks like we would with JavaScript promises, the Rust model allows us to just not poll our future.
-To yield values from a coroutine, simply bring in a UseState handle and set the value whenever your coroutine completes its work.
The future must be 'static – so any values captured by the task cannot carry any references to cx, such as a UseState.
You can use to_owned to create a clone of the hook handle which can be moved into the async closure.
---#![allow(unused)] -fn main() { -let sync_status = use_state(cx, || Status::Launching); -let sync_task = use_coroutine(cx, |rx: UnboundedReceiver<SyncAction>| { - let sync_status = sync_status.to_owned(); - async move { - loop { - delay_ms(1000).await; - sync_status.set(Status::Working); - } - } -}) -} -
To make this a bit less verbose, Dioxus exports the to_owned! macro which will create a binding as shown above, which can be quite helpful when dealing with many values.
--#![allow(unused)] -fn main() { -let sync_status = use_state(cx, || Status::Launching); -let load_status = use_state(cx, || Status::Launching); -let sync_task = use_coroutine(cx, |rx: UnboundedReceiver<SyncAction>| { - to_owned![sync_status, load_status]; - async move { - // ... - } -}) -} -
You might've noticed the use_coroutine closure takes an argument called rx. What is that? Well, a common pattern in complex apps is to handle a bunch of async code at once. With libraries like Redux Toolkit, managing multiple promises at once can be challenging and a common source of bugs.
With Coroutines, we can centralize our async logic. The rx parameter is an Channel that allows code external to the coroutine to send data into the coroutine. Instead of looping on an external service, we can loop on the channel itself, processing messages from within our app without needing to spawn a new future. To send data into the coroutine, we would call "send" on the handle.
--#![allow(unused)] -fn main() { -use futures_util::stream::StreamExt; - -enum ProfileUpdate { - SetUsername(String), - SetAge(i32) -} - -let profile = use_coroutine(cx, |mut rx: UnboundedReciver<ProfileUpdate>| async move { - let mut server = connect_to_server().await; - - while let Ok(msg) = rx.next().await { - match msg { - ProfileUpdate::SetUsername(name) => server.update_username(name).await, - ProfileUpdate::SetAge(age) => server.update_age(age).await, - } - } -}); - - -cx.render(rsx!{ - button { - onclick: move |_| profile.send(ProfileUpdate::SetUsername("Bob".to_string())), - "Update username" - } -}) -} -
--Note: In order to use/run the
-rx.next().awaitstatement you will need to extend the [Stream] trait (used by [UnboundedReceiver]) by adding 'futures_util' as a dependency to your project and adding theuse futures_util::stream::StreamExt;.
For sufficiently complex apps, we could build a bunch of different useful "services" that loop on channels to update the app.
---#![allow(unused)] -fn main() { -let profile = use_coroutine(cx, profile_service); -let editor = use_coroutine(cx, editor_service); -let sync = use_coroutine(cx, sync_service); - -async fn profile_service(rx: UnboundedReceiver<ProfileCommand>) { - // do stuff -} - -async fn sync_service(rx: UnboundedReceiver<SyncCommand>) { - // do stuff -} - -async fn editor_service(rx: UnboundedReceiver<EditorCommand>) { - // do stuff -} -} -
We can combine coroutines with Fermi to emulate Redux Toolkit's Thunk system with much less headache. This lets us store all of our app's state within a task and then simply update the "view" values stored in Atoms. It cannot be understated how powerful this technique is: we get all the perks of native Rust tasks with the optimizations and ergonomics of global state. This means your actual state does not need to be tied up in a system like Fermi or Redux – the only Atoms that need to exist are those that are used to drive the display/UI.
---#![allow(unused)] -fn main() { -static USERNAME: Atom<String> = |_| "default".to_string(); - -fn app(cx: Scope) -> Element { - let atoms = use_atom_root(cx); - - use_coroutine(cx, |rx| sync_service(rx, atoms.clone())); - - cx.render(rsx!{ - Banner {} - }) -} - -fn Banner(cx: Scope) -> Element { - let username = use_read(cx, USERNAME); - - cx.render(rsx!{ - h1 { "Welcome back, {username}" } - }) -} -} -
Now, in our sync service, we can structure our state however we want. We only need to update the view values when ready.
---#![allow(unused)] -fn main() { -use futures_util::stream::StreamExt; - -enum SyncAction { - SetUsername(String), -} - -async fn sync_service(mut rx: UnboundedReceiver<SyncAction>, atoms: AtomRoot) { - let username = atoms.write(USERNAME); - let errors = atoms.write(ERRORS); - - while let Ok(msg) = rx.next().await { - match msg { - SyncAction::SetUsername(name) => { - if set_name_on_server(&name).await.is_ok() { - username.set(name); - } else { - errors.make_mut().push("SetUsernameFailed"); - } - } - } - } -} -} -
Coroutine handles are automatically injected through the context API. You can use the use_coroutine_handle hook with the message type as a generic to fetch a handle.
- --#![allow(unused)] -fn main() { -fn Child(cx: Scope) -> Element { - let sync_task = use_coroutine_handle::<SyncAction>(cx); - - sync_task.send(SyncAction::SetUsername); -} -} -
use_future lets you run an async closure, and provides you with its result.
For example, we can make an API request (using reqwest) inside use_future:
--#![allow(unused)] -fn main() { -let future = use_future(cx, (), |_| async move { - reqwest::get("https://dog.ceo/api/breeds/image/random") - .await - .unwrap() - .json::<ApiResponse>() - .await -}); -} -
The code inside use_future will be submitted to the Dioxus scheduler once the component has rendered.
We can use .value() to get the result of the future. On the first run, since there's no data ready when the component loads, its value will be None. However, once the future is finished, the component will be re-rendered and the value will now be Some(...), containing the return value of the closure.
We can then render that result:
---#![allow(unused)] -fn main() { -cx.render(match future.value() { - Some(Ok(response)) => rsx! { - button { - onclick: move |_| future.restart(), - "Click to fetch another doggo" - } - div { - img { - max_width: "500px", - max_height: "500px", - src: "{response.image_url}", - } - } - }, - Some(Err(_)) => rsx! { div { "Loading dogs failed" } }, - None => rsx! { div { "Loading dogs..." } }, -}) -} -
The UseFuture handle provides a restart method. It can be used to execute the future again, producing a new value.
Often, you will need to run the future again every time some value (e.g. a prop) changes. Rather than calling restart manually, you can provide a tuple of "dependencies" to the hook. It will automatically re-run the future when any of those dependencies change. Example:
- --#![allow(unused)] -fn main() { -let future = use_future(cx, (breed,), |(breed,)| async move { - reqwest::get(format!("https://dog.ceo/api/breed/{breed}/images/random")) - .await - .unwrap() - .json::<ApiResponse>() - .await -}); -} -
This example shows what not to do and provides a reason why a given pattern is considered an "AntiPattern". Most anti-patterns are considered wrong for performance or code re-usability reasons.
-Fragments don't mount a physical element to the DOM immediately, so Dioxus must recurse into its children to find a physical DOM node. This process is called "normalization". This means that deeply nested fragments make Dioxus perform unnecessary work. Prefer one or two levels of fragments / nested components until presenting a true DOM element.
-Only Component and Fragment nodes are susceptible to this issue. Dioxus mitigates this with components by providing an API for registering shared state without the Context Provider pattern.
---#![allow(unused)] -fn main() { - // ❌ Don't unnecessarily nest fragments - let _ = cx.render(rsx!( - Fragment { - Fragment { - Fragment { - Fragment { - Fragment { - div { "Finally have a real node!" } - } - } - } - } - } - )); - - // ✅ Render shallow structures - cx.render(rsx!( - div { "Finally have a real node!" } - )) -} -
As described in the dynamic rendering chapter, list items must have unique keys that are associated with the same items across renders. This helps Dioxus associate state with the contained components and ensures good diffing performance. Do not omit keys, unless you know that the list will never change.
---#![allow(unused)] -fn main() { - let data: &HashMap<_, _> = &cx.props.data; - - // ❌ No keys - cx.render(rsx! { - ul { - data.values().map(|value| rsx!( - li { "List item: {value}" } - )) - } - }); - - // ❌ Using index as keys - cx.render(rsx! { - ul { - cx.props.data.values().enumerate().map(|(index, value)| rsx!( - li { key: "{index}", "List item: {value}" } - )) - } - }); - - // ✅ Using unique IDs as keys: - cx.render(rsx! { - ul { - cx.props.data.iter().map(|(key, value)| rsx!( - li { key: "{key}", "List item: {value}" } - )) - } - }) -} -
While it is technically acceptable to have a Mutex or a RwLock in the props, they will be difficult to use.
Suppose you have a struct User containing the field username: String. If you pass a Mutex<User> prop to a UserComponent component, that component may wish to pass the username as a &str prop to a child component. However, it cannot pass that borrowed field down, since it only would live as long as the Mutex's lock, which belongs to the UserComponent function. Therefore, the component will be forced to clone the username field.
Every time you update the state, Dioxus needs to re-render the component – this is inefficient! Consider refactoring your code to avoid this.
-Also, if you unconditionally update the state during render, it will be re-rendered in an infinite loop.
- -A selling point of Rust for web development is the reliability of always knowing where errors can occur and being forced to handle them
-However, we haven't talked about error handling at all in this guide! In this chapter, we'll cover some strategies in handling errors to ensure your app never crashes.
-Astute observers might have noticed that Element is actually a type alias for Option<VNode>. You don't need to know what a VNode is, but it's important to recognize that we could actually return nothing at all:
--#![allow(unused)] -fn main() { -fn App(cx: Scope) -> Element { - None -} -} -
This lets us add in some syntactic sugar for operations we think shouldn't fail, but we're still not confident enough to "unwrap" on.
---The nature of
-Option<VNode>might change in the future as thetrytrait gets upgraded.
--#![allow(unused)] -fn main() { -fn App(cx: Scope) -> Element { - // immediately return "None" - let name = cx.use_hook(|_| Some("hi"))?; -} -} -
Because Rust can't accept both Options and Results with the existing try infrastructure, you'll need to manually handle Results. This can be done by converting them into Options or by explicitly handling them.
---#![allow(unused)] -fn main() { -fn App(cx: Scope) -> Element { - // Convert Result to Option - let name = cx.use_hook(|_| "1.234").parse().ok()?; - - - // Early return - let count = cx.use_hook(|_| "1.234"); - let val = match count.parse() { - Ok(val) => val - Err(err) => return cx.render(rsx!{ "Parsing failed" }) - }; -} -} -
Notice that while hooks in Dioxus do not like being called in conditionals or loops, they are okay with early returns. Returning an error state early is a completely valid way of handling errors.
-The next "best" way of handling errors in Dioxus is to match on the error locally. This is the most robust way of handling errors, though it doesn't scale to architectures beyond a single component.
-To do this, we simply have an error state built into our component:
---#![allow(unused)] -fn main() { -let err = use_state(cx, || None); -} -
Whenever we perform an action that generates an error, we'll set that error state. We can then match on the error in a number of ways (early return, return Element, etc).
---#![allow(unused)] -fn main() { -fn Commandline(cx: Scope) -> Element { - let error = use_state(cx, || None); - - cx.render(match *error { - Some(error) => rsx!( - h1 { "An error occured" } - ) - None => rsx!( - input { - oninput: move |_| error.set(Some("bad thing happened!")), - } - ) - }) -} -} -
If you're dealing with a handful of components with minimal nesting, you can just pass the error handle into child components.
---#![allow(unused)] -fn main() { -fn Commandline(cx: Scope) -> Element { - let error = use_state(cx, || None); - - if let Some(error) = **error { - return cx.render(rsx!{ "An error occured" }); - } - - cx.render(rsx!{ - Child { error: error.clone() } - Child { error: error.clone() } - Child { error: error.clone() } - Child { error: error.clone() } - }) -} -} -
Much like before, our child components can manually set the error during their own actions. The advantage to this pattern is that we can easily isolate error states to a few components at a time, making our app more predictable and robust.
-A strategy for handling cascaded errors in larger apps is through signaling an error using global state. This particular pattern involves creating an "error" context, and then setting it wherever relevant. This particular method is not as "sophisticated" as React's error boundary, but it is more fitting for Rust.
-To get started, consider using a built-in hook like use_context and use_context_provider or Fermi. Of course, it's pretty easy to roll your own hook too.
At the "top" of our architecture, we're going to want to explicitly declare a value that could be an error.
---#![allow(unused)] -fn main() { -enum InputError { - None, - TooLong, - TooShort, -} - -static INPUT_ERROR: Atom<InputError> = |_| InputError::None; -} -
Then, in our top level component, we want to explicitly handle the possible error state for this part of the tree.
---#![allow(unused)] -fn main() { -fn TopLevel(cx: Scope) -> Element { - let error = use_read(cx, INPUT_ERROR); - - match error { - TooLong => return cx.render(rsx!{ "FAILED: Too long!" }), - TooShort => return cx.render(rsx!{ "FAILED: Too Short!" }), - _ => {} - } -} -} -
Now, whenever a downstream component has an error in its actions, it can simply just set its own error state:
---#![allow(unused)] -fn main() { -fn Commandline(cx: Scope) -> Element { - let set_error = use_set(cx, INPUT_ERROR); - - cx.render(rsx!{ - input { - oninput: move |evt| { - if evt.value.len() > 20 { - set_error(InputError::TooLong); - } - } - } - }) -} -} -
This approach to error handling is best in apps that have "well defined" error states. Consider using a crate like thiserror or anyhow to simplify the generation of the error types.
This pattern is widely popular in many contexts and is particularly helpful whenever your code generates a non-recoverable error. You can gracefully capture these "global" error states without panicking or mucking up state.
- -As much as possible, break your code down into small, reusable components and hooks, instead of implementing large chunks of the UI in a single component. This will help you keep the code maintainable – it is much easier to e.g. add, remove or re-order parts of the UI if it is organized in components.
-Organize your components in modules to keep the codebase easy to navigate!
-While it is possible to share state between components, this should only be done when necessary. Any component that is associated with a particular state object needs to be re-rendered when that state changes. For this reason:
-This document outlines some of the overall goals for Dioxus. These goals are not set in stone, but they represent general guidelines for the project.
-The goal of Dioxus is to make it easy to build cross-platform applications that scale.
-Dioxus is designed to be cross-platform by default. This means that it should be easy to build applications that run on the web, desktop, and mobile. However, Dioxus should also be flexible enough to allow users to opt into platform-specific features when needed. The use_eval is one example of this. By default, Dioxus does not assume that the platform supports JavaScript, but it does provide a hook that allows users to opt into JavaScript when needed.
As Dioxus applications grow, they should remain relatively performant without the need for manual optimizations. There will be cases where manual optimizations are needed, but Dioxus should try to make these cases as rare as possible.
-One of the benefits of the core architecture of Dioxus is that it delivers reasonable performance even when components are rerendered often. It is based on a Virtual Dom which performs diffing which should prevent unnecessary re-renders even when large parts of the component tree are rerun. On top of this, Dioxus groups static parts of the RSX tree together to skip diffing them entirely.
-As teams grow, the Type safety of Rust is a huge advantage. Dioxus should leverage this advantage to make it easy to build applications with large teams.
-To take full advantage of Rust's type system, Dioxus should try to avoid exposing public Any types and string-ly typed APIs where possible.
Dioxus should be easy to learn and ergonomic to use.
-The API of Dioxus attempts to remain close to React's API where possible. This makes it easier for people to learn Dioxus if they already know React
-We can avoid the tradeoff between simplicity and flexibility by providing multiple layers of API: One for the very common use case, one for low-level control
-cx.hook provides a way to access the underlying persistent reference if needed.Documentation:
-Development happens in the Dioxus GitHub repository. If you've found a bug or have an idea for a feature, please submit an issue (but first check if someone hasn't done it already).
-GitHub discussions can be used as a place to ask for help or talk about features. You can also join our Discord channel where some development discussion happens.
-If you'd like to improve the docs, PRs are welcome! Both Rust docs (source) and this guide (source) can be found in the GitHub repo.
-Part of what makes React great is the rich ecosystem. We'd like the same for Dioxus! So if you have a library in mind that you'd like to write and many people would benefit from, it will be appreciated. You can browse npm.js for inspiration. Once you are done, add your library to the awesome dioxus list or share it in the #I-made-a-thing channel on Discord.
If you've fixed an open issue, feel free to submit a PR! You can also take a look at the roadmap and work on something in there. Consider reaching out to the team first to make sure everyone's on the same page, and you don't do useless work!
-All pull requests (including those made by a team member) must be approved by at least one other team member. -Larger, more nuanced decisions about design, architecture, breaking changes, trade-offs, etc. are made by team consensus.
-The following tools can be helpful when developing Dioxus. Many of these tools are used in the CI pipeline. Running them locally before submitting a PR instead of waiting for CI can save time.
-cargo fmt --all
-
-cargo check --workspace --examples --tests
-
-cargo clippy --workspace --examples --tests -- -D warnings
-
-dioxus-core and dioxus-native-core.cargo miri test --package dioxus-core --test miri_stress
-cargo miri test --package dioxus-native-core --test miri_native
-
-There are many packages in the Dioxus organization. This document will help you understand the purpose of each package and how they fit together.
-Copy version of UseRefThis feature set and roadmap can help you decide if what Dioxus can do today works for you.
-If a feature that you need doesn't exist or you want to contribute to projects on the roadmap, feel free to get involved by joining the discord.
-Generally, here's the status of each platform:
-Web: Dioxus is a great choice for pure web-apps – especially for CRUD/complex apps. However, it does lack the ecosystem of React, so you might be missing a component library or some useful hook.
-SSR: Dioxus is a great choice for pre-rendering, hydration, and rendering HTML on a web endpoint. Be warned – the VirtualDom is not (currently) Send + Sync.
Desktop: You can build very competent single-window desktop apps right now. However, multi-window apps require support from Dioxus core and are not ready.
-Mobile: Mobile support is very young. You'll be figuring things out as you go and there are not many support crates for peripherals.
-LiveView: LiveView support is very young. You'll be figuring things out as you go. Thankfully, none of it is too hard and any work can be upstreamed into Dioxus.
-| Feature | Status | Description |
|---|---|---|
| Conditional Rendering | ✅ | if/then to hide/show component |
| Map, Iterator | ✅ | map/filter/reduce to produce rsx! |
| Keyed Components | ✅ | advanced diffing with keys |
| Web | ✅ | renderer for web browser |
| Desktop (webview) | ✅ | renderer for desktop |
| Shared State (Context) | ✅ | share state through the tree |
| Hooks | ✅ | memory cells in components |
| SSR | ✅ | render directly to string |
| Component Children | ✅ | cx.children() as a list of nodes |
| Headless components | ✅ | components that don't return real elements |
| Fragments | ✅ | multiple elements without a real root |
| Manual Props | ✅ | Manually pass in props with spread syntax |
| Controlled Inputs | ✅ | stateful wrappers around inputs |
| CSS/Inline Styles | ✅ | syntax for inline styles/attribute groups |
| Custom elements | ✅ | Define new element primitives |
| Suspense | ✅ | schedule future render from future/promise |
| Integrated error handling | ✅ | Gracefully handle errors with ? syntax |
| NodeRef | ✅ | gain direct access to nodes |
| Re-hydration | ✅ | Pre-render to HTML to speed up first contentful paint |
| Jank-Free Rendering | ✅ | Large diffs are segmented across frames for silky-smooth transitions |
| Effects | ✅ | Run effects after a component has been committed to render |
| Portals | 🛠 | Render nodes outside of the traditional tree structure |
| Cooperative Scheduling | 🛠 | Prioritize important events over non-important events |
| Server Components | 🛠 | Hybrid components for SPA and Server |
| Bundle Splitting | 👀 | Efficiently and asynchronously load the app |
| Lazy Components | 👀 | Dynamically load the new components as the page is loaded |
| 1st class global state | ✅ | redux/recoil/mobx on top of context |
| Runs natively | ✅ | runs as a portable binary w/o a runtime (Node) |
| Subtree Memoization | ✅ | skip diffing static element subtrees |
| High-efficiency templates | ✅ | rsx! calls are translated to templates on the DOM's side |
| Compile-time correct | ✅ | Throw errors on invalid template layouts |
| Heuristic Engine | ✅ | track component memory usage to minimize future allocations |
| Fine-grained reactivity | 👀 | Skip diffing for fine-grain updates |
These Features are planned for the future of Dioxus:
-We are currently working on our own build tool called Dioxus CLI which will support:
-rsx!While not currently fully implemented, the expectation is that LiveView apps can be a hybrid between Wasm and server-rendered where only portions of a page are "live" and the rest of the page is either server-rendered, statically generated, or handled by the host SPA.
-We are currently working on a native renderer for Dioxus using WGPU called Blitz. This will allow you to build apps that are rendered natively for iOS, Android, and Desktop.
- -This walkthrough will take you through the internals of the Hello World example program. It will explain how major parts of Dioxus internals interact with each other to take the readme example from a source file to a running application. This guide should serve as a high-level overview of the internals of Dioxus. It is not meant to be a comprehensive guide.
-We start will a hello world program. This program renders a desktop app with the text "Hello World" in a webview.
-- -//! Example: README.md showcase -//! -//! The example from the README.md. - -use dioxus::prelude::*; - -fn main() { - dioxus_desktop::launch(app); -} - -fn app(cx: Scope) -> Element { - let mut count = use_state(cx, || 0); - - cx.render(rsx! { - h1 { "High-Five counter: {count}" } - button { onclick: move |_| count += 1, "Up high!" } - button { onclick: move |_| count -= 1, "Down low!" } - }) -} -
Before the Rust compiler runs the program, it will expand all macros. Here is what the hello world example looks like expanded:
--use dioxus::prelude::*; - -fn main() { - dioxus_desktop::launch(app); -} - -fn app(cx: Scope) -> Element { - let mut count = use_state(cx, || 0); - - cx.render( - // rsx expands to LazyNodes::new - ::dioxus::core::LazyNodes::new( - move |__cx: &::dioxus::core::ScopeState| -> ::dioxus::core::VNode { - // The template is every static part of the rsx - static TEMPLATE: ::dioxus::core::Template = ::dioxus::core::Template { - // This is the source location of the rsx that generated this template. This is used to make hot rsx reloading work. Hot rsx reloading just replaces the template with a new one generated from the rsx by the CLI. - name: "examples\\readme.rs:14:15:250", - // The root nodes are the top level nodes of the rsx - roots: &[ - // The h1 node - ::dioxus::core::TemplateNode::Element { - // Find the built in h1 tag in the dioxus_elements crate exported by the dioxus html crate - tag: dioxus_elements::h1::TAG_NAME, - namespace: dioxus_elements::h1::NAME_SPACE, - attrs: &[], - // The children of the h1 node - children: &[ - // The dynamic count text node - // Any nodes that are dynamic have a dynamic placeholder with a unique index - ::dioxus::core::TemplateNode::DynamicText { - // This index is used to find what element in `dynamic_nodes` to use instead of the placeholder - id: 0usize, - }, - ], - }, - // The up high button node - ::dioxus::core::TemplateNode::Element { - tag: dioxus_elements::button::TAG_NAME, - namespace: dioxus_elements::button::NAME_SPACE, - attrs: &[ - // The dynamic onclick listener attribute - // Any attributes that are dynamic have a dynamic placeholder with a unique index. - ::dioxus::core::TemplateAttribute::Dynamic { - // Similar to dynamic nodes, dynamic attributes have a unique index used to find the attribute in `dynamic_attrs` to use instead of the placeholder - id: 0usize, - }, - ], - children: &[::dioxus::core::TemplateNode::Text { text: "Up high!" }], - }, - // The down low button node - ::dioxus::core::TemplateNode::Element { - tag: dioxus_elements::button::TAG_NAME, - namespace: dioxus_elements::button::NAME_SPACE, - attrs: &[ - // The dynamic onclick listener attribute - ::dioxus::core::TemplateAttribute::Dynamic { id: 1usize }, - ], - children: &[::dioxus::core::TemplateNode::Text { text: "Down low!" }], - }, - ], - // Node paths is a list of paths to every dynamic node in the rsx - node_paths: &[ - // The first node path is the path to the dynamic node with an id of 0 (the count text node) - &[ - // Go to the index 0 root node - 0u8, - // - // Go to the first child of the root node - 0u8, - ], - ], - // Attr paths is a list of paths to every dynamic attribute in the rsx - attr_paths: &[ - // The first attr path is the path to the dynamic attribute with an id of 0 (the up high button onclick listener) - &[ - // Go to the index 1 root node - 1u8, - ], - // The second attr path is the path to the dynamic attribute with an id of 1 (the down low button onclick listener) - &[ - // Go to the index 2 root node - 2u8, - ], - ], - }; - // The VNode is a reference to the template with the dynamic parts of the rsx - ::dioxus::core::VNode { - parent: None, - key: None, - // The static template this node will use. The template is stored in a Cell so it can be replaced with a new template when hot rsx reloading is enabled - template: std::cell::Cell::new(TEMPLATE), - root_ids: Default::default(), - dynamic_nodes: __cx.bump().alloc([ - // The dynamic count text node (dynamic node id 0) - __cx.text_node(format_args!("High-Five counter: {0}", count)), - ]), - dynamic_attrs: __cx.bump().alloc([ - // The dynamic up high button onclick listener (dynamic attribute id 0) - dioxus_elements::events::onclick(__cx, move |_| count += 1), - // The dynamic down low button onclick listener (dynamic attribute id 1) - dioxus_elements::events::onclick(__cx, move |_| count -= 1), - ]), - } - }, - ), - ) -} -
The rsx macro separates the static parts of the rsx (the template) and the dynamic parts (the dynamic_nodes and dynamic_attributes).
-The static template only contains the parts of the rsx that cannot change at runtime with holes for the dynamic parts:
- -The dynamic_nodes and dynamic_attributes are the parts of the rsx that can change at runtime:
- -The app is launched by calling the launch function with the root component. Internally, this function will create a new web view using wry and create a virtual dom with the root component. This guide will not explain the renderer in-depth, but you can read more about it in the custom renderer section.
Before we dive into the initial render in the virtual dom, we need to discuss what the virtual dom is. The virtual dom is a representation of the dom that is used to diff the current dom from the new dom. This diff is then used to create a list of mutations that need to be applied to the dom.
-The Virtual Dom roughly looks like this:
---#![allow(unused)] -fn main() { -pub struct VirtualDom { - // All the templates that have been created or set durring hot reloading - pub(crate) templates: FxHashMap<TemplateId, FxHashMap<usize, Template<'static>>>, - - // A slab of all the scopes that have been created - pub(crate) scopes: ScopeSlab, - - // All scopes that have been marked as dirty - pub(crate) dirty_scopes: BTreeSet<DirtyScope>, - - // Every element is actually a dual reference - one to the template and the other to the dynamic node in that template - pub(crate) elements: Slab<ElementRef>, - - // This receiver is used to receive messages from hooks about what scopes need to be marked as dirty - pub(crate) rx: futures_channel::mpsc::UnboundedReceiver<SchedulerMsg>, - - // The changes queued up to be sent to the renderer - pub(crate) mutations: Mutations<'static>, -} -} -
--What is a slab? -A slab acts like a hashmap with integer keys if you don't care about the value of the keys. It is internally backed by a dense vector which makes it more efficient than a hashmap. When you insert a value into a slab, it returns an integer key that you can use to retrieve the value later.
-
--How does Dioxus use slabs? -Dioxus uses "synchronized slabs" to communicate between the renderer and the VDOM. When an node is created in the Virtual Dom, a ElementId is passed along with the mutation to the renderer to identify the node. These ids are used by the Virtual Dom to reference that nodes in future mutations like setting an attribute on a node or removing a node. -When the renderer sends an event to the Virtual Dom, it sends the ElementId of the node that the event was triggered on. The Virtual Dom uses this id to find the node in the slab and then run the necessary event handlers.
-
The virtual dom is a tree of scopes. A new scope is created for every component when it is first rendered and recycled when the component is unmounted.
-Scopes serve three main purposes:
-The root scope is created and rebuilt:
-After the root scope is built, the mutations are sent to the renderer to be applied to the dom.
-After the initial render, the root scope looks like this:
- -The Virtual Dom will only ever rerender a scope if it is marked as dirty. Each hook is responsible for marking the scope as dirty if the state has changed. Hooks can mark a scope as dirty by sending a message to the Virtual Dom's channel.
-There are generally two ways a scope is marked as dirty:
-Once at least one scope is marked as dirty, the renderer can call render_with_deadline to diff the dirty scopes.
If the user clicked the "up high" button, the root scope would be marked as dirty by the use_state hook. Once the desktop renderer calls render_with_deadline, the root scope would be diffed.
To start the diffing process, the component is run. After the root component is run it will look like this:
- -Next, the Virtual Dom will compare the new VNode with the previous VNode and only update the parts of the tree that have changed.
-When a component is re-rendered, the Virtual Dom will compare the new VNode with the previous VNode and only update the parts of the tree that have changed.
-The diffing algorithm goes through the list of dynamic attributes and nodes and compares them to the previous VNode. If the attribute or node has changed, a mutation that describes the change is added to the mutation list.
-Here is what the diffing algorithm looks like for the root scope (red lines indicate that a mutation was generated, and green lines indicate that no mutation was generated)
- -This is only a brief overview of how the Virtual Dom works. There are several aspects not yet covered in this guide including how the Virtual Dom handles async-components, keyed diffing, and how it uses bump allocation to efficiently allocate VNodes. If need more information about the Virtual Dom, you can read the code of the core crate or reach out to us on Discord.
- -Dioxus is an incredibly portable framework for UI development. The lessons, knowledge, hooks, and components you acquire over time can always be used for future projects. However, sometimes those projects cannot leverage a supported renderer or you need to implement your own better renderer.
-Great news: the design of the renderer is entirely up to you! We provide suggestions and inspiration with the 1st party renderers, but only really require processing Mutations and sending UserEvents.
Implementing the renderer is fairly straightforward. The renderer needs to:
-Essentially, your renderer needs to process edits and generate events to update the VirtualDOM. From there, you'll have everything needed to render the VirtualDOM to the screen.
-Internally, Dioxus handles the tree relationship, diffing, memory management, and the event system, leaving as little as possible required for renderers to implement themselves.
-For reference, check out the javascript interpreter or tui renderer as a starting point for your custom renderer.
-Dioxus is built around the concept of Templates. Templates describe a UI tree known at compile time with dynamic parts filled at runtime. This is useful internally to make skip diffing static nodes, but it is also useful for the renderer to reuse parts of the UI tree. This can be useful for things like a list of items. Each item could contain some static parts and some dynamic parts. The renderer can use the template to create a static part of the UI once, clone it for each element in the list, and then fill in the dynamic parts.
-The Mutation type is a serialized enum that represents an operation that should be applied to update the UI. The variants roughly follow this set:
--#![allow(unused)] -fn main() { -enum Mutation { - AppendChildren, - AssignId, - CreatePlaceholder, - CreateTextNode, - HydrateText, - LoadTemplate, - ReplaceWith, - ReplacePlaceholder, - InsertAfter, - InsertBefore, - SetAttribute, - SetText, - NewEventListener, - RemoveEventListener, - Remove, - PushRoot, -} -} -
The Dioxus diffing mechanism operates as a stack machine where the LoadTemplate, CreatePlaceholder, and CreateTextNode mutations pushes a new "real" DOM node onto the stack and AppendChildren, InsertAfter, InsertBefore, ReplacePlaceholder, and ReplaceWith all remove nodes from the stack.
-Dioxus saves and loads elements with IDs. Inside the VirtualDOM, this is just tracked as as a u64.
-Whenever a CreateElement edit is generated during diffing, Dioxus increments its node counter and assigns that new element its current NodeCount. The RealDom is responsible for remembering this ID and pushing the correct node when id is used in a mutation. Dioxus reclaims the IDs of elements when removed. To stay in sync with Dioxus you can use a sparse Vec (Vec<Option
For the sake of understanding, let's consider this example – a very simple UI declaration:
---#![allow(unused)] -fn main() { -rsx!( h1 {"count: {x}"} ) -} -
The above rsx will create a template that contains one static h1 tag and a placeholder for a dynamic text node. The template contains the static parts of the UI, and ids for the dynamic parts along with the paths to access them.
-The template will look something like this:
---#![allow(unused)] -fn main() { -Template { - // Some id that is unique for the entire project - name: "main.rs:1:1:0", - // The root nodes of the template - roots: &[ - TemplateNode::Element { - tag: "h1", - namespace: None, - attrs: &[], - children: &[ - TemplateNode::DynamicText { - id: 0 - }, - ], - } - ], - // the path to each of the dynamic nodes - node_paths: &[ - // the path to dynamic node with a id of 0 - &[ - // on the first root node - 0, - // the first child of the root node - 0, - ] - ], - // the path to each of the dynamic attributes - attr_paths: &'a [&'a [u8]], -} -} -
--For more detailed docs about the struture of templates see the Template api docs
-
This template will be sent to the renderer in the list of templates supplied with the mutations the first time it is used. Any time the renderer encounters a LoadTemplate mutation after this, it should clone the template and store it in the given id.
-For dynamic nodes and dynamic text nodes, a placeholder node should be created and inserted into the UI so that the node can be modified later.
-In HTML renderers, this template could look like this:
-<h1>""</h1>
-
-After the renderer has created all of the new templates, it can begin to process the mutations.
-When the renderer starts, it should contain the Root node on the stack and store the Root node with an id of 0. The Root node is the top-level node of the UI. In HTML, this is the <div id="main"> element.
--#![allow(unused)] -fn main() { -instructions: [] -stack: [ - RootNode, -] -nodes: [ - RootNode, -] -} -
The first mutation is a LoadTemplate mutation. This tells the renderer to load a root from the template with the given id. The renderer will then push the root node of the template onto the stack and store it with an id for later. In this case, the root node is an h1 element.
--#![allow(unused)] -fn main() { -instructions: [ - LoadTemplate { - // the id of the template - name: "main.rs:1:1:0", - // the index of the root node in the template - index: 0, - // the id to store - id: ElementId(1), - } -] -stack: [ - RootNode, - <h1>""</h1>, -] -nodes: [ - RootNode, - <h1>""</h1>, -] -} -
Next, Dioxus will create the dynamic text node. The diff algorithm decides that this node needs to be created, so Dioxus will generate the Mutation HydrateText. When the renderer receives this instruction, it will navigate to the placeholder text node in the template and replace it with the new text.
--#![allow(unused)] -fn main() { -instructions: [ - LoadTemplate { - name: "main.rs:1:1:0", - index: 0, - id: ElementId(1), - }, - HydrateText { - // the id to store the text node - id: ElementId(2), - // the text to set - text: "count: 0", - } -] -stack: [ - RootNode, - <h1>"count: 0"</h1>, -] -nodes: [ - RootNode, - <h1>"count: 0"</h1>, - "count: 0", -] -} -
Remember, the h1 node is not attached to anything (it is unmounted) so Dioxus needs to generate an Edit that connects the h1 node to the Root. It depends on the situation, but in this case, we use AppendChildren. This pops the text node off the stack, leaving the Root element as the next element on the stack.
--#![allow(unused)] -fn main() { -instructions: [ - LoadTemplate { - name: "main.rs:1:1:0", - index: 0, - id: ElementId(1), - }, - HydrateText { - id: ElementId(2), - text: "count: 0", - }, - AppendChildren { - // the id of the parent node - id: ElementId(0), - // the number of nodes to pop off the stack and append - m: 1 - } -] -stack: [ - RootNode, -] -nodes: [ - RootNode, - <h1>"count: 0"</h1>, - "count: 0", -] -} -
Over time, our stack looked like this:
---#![allow(unused)] -fn main() { -[Root] -[Root, <h1>""</h1>] -[Root, <h1>"count: 0"</h1>] -[Root] -} -
Conveniently, this approach completely separates the Virtual DOM and the Real DOM. Additionally, these edits are serializable, meaning we can even manage UIs across a network connection. This little stack machine and serialized edits make Dioxus independent of platform specifics.
-Dioxus is also really fast. Because Dioxus splits the diff and patch phase, it's able to make all the edits to the RealDOM in a very short amount of time (less than a single frame) making rendering very snappy. It also allows Dioxus to cancel large diffing operations if higher priority work comes in while it's diffing.
-This little demo serves to show exactly how a Renderer would need to process a mutation stream to build UIs.
-Like most GUIs, Dioxus relies on an event loop to progress the VirtualDOM. The VirtualDOM itself can produce events as well, so it's important for your custom renderer can handle those too.
-The code for the WebSys implementation is straightforward, so we'll add it here to demonstrate how simple an event loop is:
-pub async fn run(&mut self) -> dioxus_core::error::Result<()> {
- // Push the body element onto the WebsysDom's stack machine
- let mut websys_dom = crate::new::WebsysDom::new(prepare_websys_dom());
- websys_dom.stack.push(root_node);
-
- // Rebuild or hydrate the virtualdom
- let mutations = self.internal_dom.rebuild();
- websys_dom.apply_mutations(mutations);
-
- // Wait for updates from the real dom and progress the virtual dom
- loop {
- let user_input_future = websys_dom.wait_for_event();
- let internal_event_future = self.internal_dom.wait_for_work();
-
- match select(user_input_future, internal_event_future).await {
- Either::Left((_, _)) => {
- let mutations = self.internal_dom.work_with_deadline(|| false);
- websys_dom.apply_mutations(mutations);
- },
- Either::Right((event, _)) => websys_dom.handle_event(event),
- }
-
- // render
- }
-}
-
-It's important to decode what the real events are for your event system into Dioxus' synthetic event system (synthetic meaning abstracted). This simply means matching your event type and creating a Dioxus UserEvent type. Right now, the virtual event system is modeled almost entirely around the HTML spec, but we are interested in slimming it down.
fn virtual_event_from_websys_event(event: &web_sys::Event) -> VirtualEvent {
- match event.type_().as_str() {
- "keydown" => {
- let event: web_sys::KeyboardEvent = event.clone().dyn_into().unwrap();
- UserEvent::KeyboardEvent(UserEvent {
- scope_id: None,
- priority: EventPriority::Medium,
- name: "keydown",
- // This should be whatever element is focused
- element: Some(ElementId(0)),
- data: Arc::new(KeyboardData{
- char_code: event.char_code(),
- key: event.key(),
- key_code: event.key_code(),
- alt_key: event.alt_key(),
- ctrl_key: event.ctrl_key(),
- meta_key: event.meta_key(),
- shift_key: event.shift_key(),
- location: event.location(),
- repeat: event.repeat(),
- which: event.which(),
- })
- })
- }
- _ => todo!()
- }
-}
-
-If you need to go as far as relying on custom elements/attributes for your renderer – you totally can. This still enables you to use Dioxus' reactive nature, component system, shared state, and other features, but will ultimately generate different nodes. All attributes and listeners for the HTML and SVG namespace are shuttled through helper structs that essentially compile away. You can drop in your elements any time you want, with little hassle. However, you must be sure your renderer can handle the new namespace.
-For more examples and information on how to create custom namespaces, see the dioxus_html crate.
If you are creating a renderer in rust, the native-core crate provides some utilities to implement a renderer. It provides an abstraction over Mutations and Templates and contains helpers that can handle the layout and text editing for you.
-The RealDom is a higher-level abstraction over updating the Dom. It uses an entity component system to manage the state of nodes. This system allows you to modify insert and modify arbitrary components on nodes. On top of this, the RealDom provides a way to manage a tree of nodes, and the State trait provides a way to automatically add and update these components when the tree is modified. It also provides a way to apply Mutations to the RealDom.
Let's build a toy renderer with borders, size, and text color. -Before we start let's take a look at an example element we can render:
---#![allow(unused)] -fn main() { -cx.render(rsx!{ - div{ - color: "red", - p{ - border: "1px solid black", - "hello world" - } - } -}) -} -
In this tree, the color depends on the parent's color. The layout depends on the children's layout, the current text, and the text size. The border depends on only the current node.
-In the following diagram arrows represent dataflow:
- -To help in building a Dom, native-core provides the State trait and a RealDom struct. The State trait provides a way to describe how states in a node depend on other states in its relatives. By describing how to update a single node from its relations, native-core will derive a way to update the states of all nodes for you. Once you have a state you can provide it as a generic to RealDom. RealDom provides all of the methods to interact and update your new dom.
-Native Core cannot create all of the required methods for the State trait, but it can derive some of them. To implement the State trait, you must implement the following methods and let the #[partial_derive_state] macro handle the rest:
// All states must derive Component (https://docs.rs/shipyard/latest/shipyard/derive.Component.html)
-// They also must implement Default or provide a custom implementation of create in the State trait
-#[derive(Default, Component)]
-struct MyState;
-
-/// Derive some of the boilerplate for the State implementation
-#[partial_derive_state]
-impl State for MyState {
- // The states of the parent nodes this state depends on
- type ParentDependencies = ();
-
- // The states of the child nodes this state depends on
- type ChildDependencies = (Self,);
-
- // The states of the current node this state depends on
- type NodeDependencies = ();
-
- // The parts of the current text, element, or placeholder node in the tree that this state depends on
- const NODE_MASK: NodeMaskBuilder<'static> = NodeMaskBuilder::new();
-
- // How to update the state of the current node based on the state of the parent nodes, child nodes, and the current node
- // Returns true if the node was updated and false if the node was not updated
- fn update<'a>(
- &mut self,
- // The view of the current node limited to the parts this state depends on
- _node_view: NodeView<()>,
- // The state of the current node that this state depends on
- _node: <Self::NodeDependencies as Dependancy>::ElementBorrowed<'a>,
- // The state of the parent nodes that this state depends on
- _parent: Option<<Self::ParentDependencies as Dependancy>::ElementBorrowed<'a>>,
- // The state of the child nodes that this state depends on
- _children: Vec<<Self::ChildDependencies as Dependancy>::ElementBorrowed<'a>>,
- // The context of the current node used to pass global state into the tree
- _context: &SendAnyMap,
- ) -> bool {
- todo!()
- }
-
- // partial_derive_state will generate a default implementation of all the other methods
-}
-
-Lets take a look at how to implement the State trait for a simple renderer.
---#![allow(unused)] -fn main() { -struct FontSize(f64); - -// All states need to derive Component -#[derive(Default, Debug, Copy, Clone, Component)] -struct Size(f64, f64); - -/// Derive some of the boilerplate for the State implementation -#[partial_derive_state] -impl State for Size { - type ParentDependencies = (); - - // The size of the current node depends on the size of its children - type ChildDependencies = (Self,); - - type NodeDependencies = (); - - // Size only cares about the width, height, and text parts of the current node - const NODE_MASK: NodeMaskBuilder<'static> = NodeMaskBuilder::new() - // Get access to the width and height attributes - .with_attrs(AttributeMaskBuilder::Some(&["width", "height"])) - // Get access to the text of the node - .with_text(); - - fn update<'a>( - &mut self, - node_view: NodeView<()>, - _node: <Self::NodeDependencies as Dependancy>::ElementBorrowed<'a>, - _parent: Option<<Self::ParentDependencies as Dependancy>::ElementBorrowed<'a>>, - children: Vec<<Self::ChildDependencies as Dependancy>::ElementBorrowed<'a>>, - context: &SendAnyMap, - ) -> bool { - let font_size = context.get::<FontSize>().unwrap().0; - let mut width; - let mut height; - if let Some(text) = node_view.text() { - // if the node has text, use the text to size our object - width = text.len() as f64 * font_size; - height = font_size; - } else { - // otherwise, the size is the maximum size of the children - width = children - .iter() - .map(|(item,)| item.0) - .reduce(|accum, item| if accum >= item { accum } else { item }) - .unwrap_or(0.0); - - height = children - .iter() - .map(|(item,)| item.1) - .reduce(|accum, item| if accum >= item { accum } else { item }) - .unwrap_or(0.0); - } - // if the node contains a width or height attribute it overrides the other size - for a in node_view.attributes().into_iter().flatten() { - match &*a.attribute.name { - "width" => width = a.value.as_float().unwrap(), - "height" => height = a.value.as_float().unwrap(), - // because Size only depends on the width and height, no other attributes will be passed to the member - _ => panic!(), - } - } - // to determine what other parts of the dom need to be updated we return a boolean that marks if this member changed - let changed = (width != self.0) || (height != self.1); - *self = Self(width, height); - changed - } -} - -#[derive(Debug, Clone, Copy, PartialEq, Default, Component)] -struct TextColor { - r: u8, - g: u8, - b: u8, -} - -#[partial_derive_state] -impl State for TextColor { - // TextColor depends on the TextColor part of the parent - type ParentDependencies = (Self,); - - type ChildDependencies = (); - - type NodeDependencies = (); - - // TextColor only cares about the color attribute of the current node - const NODE_MASK: NodeMaskBuilder<'static> = - // Get access to the color attribute - NodeMaskBuilder::new().with_attrs(AttributeMaskBuilder::Some(&["color"])); - - fn update<'a>( - &mut self, - node_view: NodeView<()>, - _node: <Self::NodeDependencies as Dependancy>::ElementBorrowed<'a>, - parent: Option<<Self::ParentDependencies as Dependancy>::ElementBorrowed<'a>>, - _children: Vec<<Self::ChildDependencies as Dependancy>::ElementBorrowed<'a>>, - _context: &SendAnyMap, - ) -> bool { - // TextColor only depends on the color tag, so getting the first tag is equivilent to looking through all tags - let new = match node_view - .attributes() - .and_then(|mut attrs| attrs.next()) - .and_then(|attr| attr.value.as_text()) - { - // if there is a color tag, translate it - Some("red") => TextColor { r: 255, g: 0, b: 0 }, - Some("green") => TextColor { r: 0, g: 255, b: 0 }, - Some("blue") => TextColor { r: 0, g: 0, b: 255 }, - Some(color) => panic!("unknown color {color}"), - // otherwise check if the node has a parent and inherit that color - None => match parent { - Some((parent,)) => *parent, - None => Self::default(), - }, - }; - // check if the member has changed - let changed = new != *self; - *self = new; - changed - } -} - -#[derive(Debug, Clone, Copy, PartialEq, Default, Component)] -struct Border(bool); - -#[partial_derive_state] -impl State for Border { - // TextColor depends on the TextColor part of the parent - type ParentDependencies = (Self,); - - type ChildDependencies = (); - - type NodeDependencies = (); - - // Border does not depended on any other member in the current node - const NODE_MASK: NodeMaskBuilder<'static> = - // Get access to the border attribute - NodeMaskBuilder::new().with_attrs(AttributeMaskBuilder::Some(&["border"])); - - fn update<'a>( - &mut self, - node_view: NodeView<()>, - _node: <Self::NodeDependencies as Dependancy>::ElementBorrowed<'a>, - _parent: Option<<Self::ParentDependencies as Dependancy>::ElementBorrowed<'a>>, - _children: Vec<<Self::ChildDependencies as Dependancy>::ElementBorrowed<'a>>, - _context: &SendAnyMap, - ) -> bool { - // check if the node contians a border attribute - let new = Self( - node_view - .attributes() - .and_then(|mut attrs| attrs.next().map(|a| a.attribute.name == "border")) - .is_some(), - ); - // check if the member has changed - let changed = new != *self; - *self = new; - changed - } -} -} -
Now that we have our state, we can put it to use in our RealDom. We can update the RealDom with apply_mutations to update the structure of the dom (adding, removing, and changing properties of nodes) and then update_state to update the States for each of the nodes that changed.
--fn main() -> Result<(), Box<dyn std::error::Error>> { - fn app(cx: Scope) -> Element { - let count = use_state(cx, || 0); - - use_future(cx, (count,), |(count,)| async move { - loop { - tokio::time::sleep(std::time::Duration::from_secs(1)).await; - count.set(*count + 1); - } - }); - - cx.render(rsx! { - div{ - color: "red", - "{count}" - } - }) - } - - // create the vdom, the real_dom, and the binding layer between them - let mut vdom = VirtualDom::new(app); - let mut rdom: RealDom = RealDom::new([ - Border::to_type_erased(), - TextColor::to_type_erased(), - Size::to_type_erased(), - ]); - let mut dioxus_intigration_state = DioxusState::create(&mut rdom); - - let mutations = vdom.rebuild(); - // update the structure of the real_dom tree - dioxus_intigration_state.apply_mutations(&mut rdom, mutations); - let mut ctx = SendAnyMap::new(); - // set the font size to 3.3 - ctx.insert(FontSize(3.3)); - // update the State for nodes in the real_dom tree - let _to_rerender = rdom.update_state(ctx); - - // we need to run the vdom in a async runtime - tokio::runtime::Builder::new_current_thread() - .enable_all() - .build()? - .block_on(async { - loop { - // wait for the vdom to update - vdom.wait_for_work().await; - - // get the mutations from the vdom - let mutations = vdom.render_immediate(); - - // update the structure of the real_dom tree - dioxus_intigration_state.apply_mutations(&mut rdom, mutations); - - // update the state of the real_dom tree - let mut ctx = SendAnyMap::new(); - // set the font size to 3.3 - ctx.insert(FontSize(3.3)); - let _to_rerender = rdom.update_state(ctx); - - // render... - rdom.traverse_depth_first(|node| { - let indent = " ".repeat(node.height() as usize); - let color = *node.get::<TextColor>().unwrap(); - let size = *node.get::<Size>().unwrap(); - let border = *node.get::<Border>().unwrap(); - let id = node.id(); - let node = node.node_type(); - let node_type = &*node; - println!("{indent}{id:?} {color:?} {size:?} {border:?} {node_type:?}"); - }); - } - }) -} -
For most platforms, the layout of the Elements will stay the same. The layout_attributes module provides a way to apply HTML attributes a Taffy layout style.
-To make it easier to implement text editing in rust renderers, native-core also contains a renderer-agnostic cursor system. The cursor can handle text editing, selection, and movement with common keyboard shortcuts integrated.
--#![allow(unused)] -fn main() { -fn text_editing() { - let mut cursor = Cursor::default(); - let mut text = String::new(); - - // handle keyboard input with a max text length of 10 - cursor.handle_input( - &Code::ArrowRight, - &Key::ArrowRight, - &Modifiers::empty(), - &mut text, - 10, - ); - - // mannually select text between characters 0-5 on the first line (this could be from dragging with a mouse) - cursor.start = Pos::new(0, 0); - cursor.end = Some(Pos::new(5, 0)); - - // delete the selected text and move the cursor to the start of the selection - cursor.delete_selection(&mut text); -} -} -
That should be it! You should have nearly all the knowledge required on how to implement your renderer. We're super interested in seeing Dioxus apps brought to custom desktop renderers, mobile renderers, video game UI, and even augmented reality! If you're interested in contributing to any of these projects, don't be afraid to reach out or join the community.
- -In some cases, you may wish to create a component that acts as a container for some other content, without the component needing to know what that content is. To achieve this, create a prop of type Element:
--#![allow(unused)] -fn main() { -#[derive(Props)] -struct ClickableProps<'a> { - href: &'a str, - body: Element<'a>, -} - -fn Clickable<'a>(cx: Scope<'a, ClickableProps<'a>>) -> Element { - cx.render(rsx!( - a { - href: "{cx.props.href}", - class: "fancy-button", - &cx.props.body - } - )) -} -} -
Then, when rendering the component, you can pass in the output of cx.render(rsx!(...)):
--#![allow(unused)] -fn main() { - cx.render(rsx! { - Clickable { - href: "https://www.youtube.com/watch?v=C-M2hs3sXGo", - body: cx.render(rsx!("How to " i {"not"} " be seen")), - } - }) -} -
--Note: Since
-Element<'a>is a borrowed prop, there will be no memoization.
--Warning: While it may compile, do not include the same
-Elementmore than once in the RSX. The resulting behavior is unspecified.
children fieldRather than passing the RSX through a regular prop, you may wish to accept children similarly to how elements can have children. The "magic" children prop lets you achieve this:
--#![allow(unused)] -fn main() { -#[derive(Props)] -struct ClickableProps<'a> { - href: &'a str, - children: Element<'a>, -} - -fn Clickable<'a>(cx: Scope<'a, ClickableProps<'a>>) -> Element { - cx.render(rsx!( - a { - href: "{cx.props.href}", - class: "fancy-button", - &cx.props.children - } - )) -} -} -
This makes using the component much simpler: simply put the RSX inside the {} brackets – and there is no need for a render call or another macro!
- --#![allow(unused)] -fn main() { - cx.render(rsx! { - Clickable { - href: "https://www.youtube.com/watch?v=C-M2hs3sXGo", - "How to " i {"not"} " be seen" - } - }) -} -
Just like you can pass arguments to a function, you can pass props to a component that customize its behavior! The components we've seen so far didn't accept any props – so let's write some components that do.
-#[derive(Props)]Component props are a single struct annotated with #[derive(Props)]. For a component to accept props, the type of its argument must be Scope<YourPropsStruct>. Then, you can access the value of the props using cx.props.
There are 2 flavors of Props structs:
-PartialEq, allow for memoization (if the props don't change, Dioxus won't re-render the component)Owned Props are very simple – they don't borrow anything. Example:
---#![allow(unused)] -fn main() { -// Remember: Owned props must implement `PartialEq`! -#[derive(PartialEq, Props)] -struct LikesProps { - score: i32, -} - -fn Likes(cx: Scope<LikesProps>) -> Element { - cx.render(rsx! { - div { - "This post has ", - b { "{cx.props.score}" }, - " likes" - } - }) -} -} -
You can then pass prop values to the component the same way you would pass attributes to an element:
---#![allow(unused)] -fn main() { -fn App(cx: Scope) -> Element { - cx.render(rsx! { - Likes { - score: 42, - }, - }) -} -} -

Owned props work well if your props are easy to copy around – like a single number. But what if we need to pass a larger data type, like a String from an App Component to a TitleCard subcomponent? A naive solution might be to .clone() the String, creating a copy of it for the subcomponent – but this would be inefficient, especially for larger Strings.
Rust allows for something more efficient – borrowing the String as a &str – this is what Borrowed Props are for!
--#![allow(unused)] -fn main() { -#[derive(Props)] -struct TitleCardProps<'a> { - title: &'a str, -} - -fn TitleCard<'a>(cx: Scope<'a, TitleCardProps<'a>>) -> Element { - cx.render(rsx! { - h1 { "{cx.props.title}" } - }) -} -} -
We can then use the component like this:
---#![allow(unused)] -fn main() { -fn App(cx: Scope) -> Element { - let hello = "Hello Dioxus!"; - - cx.render(rsx!(TitleCard { title: hello })) -} -} -

Borrowed props can be very useful, but they do not allow for memorization so they will always rerun when the parent scope is rerendered. Because of this Borrowed Props should be reserved for components that are cheap to rerun or places where cloning data is an issue. Using Borrowed Props everywhere will result in large parts of your app rerunning every interaction.
-The #[derive(Props)] macro has some features that let you customize the behavior of props.
You can create optional fields by using the Option<…> type for a field:
--#![allow(unused)] -fn main() { -#[derive(Props)] -struct OptionalProps<'a> { - title: &'a str, - subtitle: Option<&'a str>, -} - -fn Title<'a>(cx: Scope<'a, OptionalProps>) -> Element<'a> { - cx.render(rsx!(h1{ - "{cx.props.title}: ", - cx.props.subtitle.unwrap_or("No subtitle provided"), - })) -} -} -
Then, you can choose to either provide them or not:
---#![allow(unused)] -fn main() { -Title { - title: "Some Title", -}, -Title { - title: "Some Title", - subtitle: "Some Subtitle", -}, -// Providing an Option explicitly won't compile though: -// Title { -// title: "Some Title", -// subtitle: None, -// }, -} -
OptionsIf you want to explicitly require an Option, and not an optional prop, you can annotate it with #[props(!optional)]:
--#![allow(unused)] -fn main() { -#[derive(Props)] -struct ExplicitOptionProps<'a> { - title: &'a str, - #[props(!optional)] - subtitle: Option<&'a str>, -} - -fn ExplicitOption<'a>(cx: Scope<'a, ExplicitOptionProps>) -> Element<'a> { - cx.render(rsx!(h1 { - "{cx.props.title}: ", - cx.props.subtitle.unwrap_or("No subtitle provided"), - })) -} -} -
Then, you have to explicitly pass either Some("str") or None:
--#![allow(unused)] -fn main() { -ExplicitOption { - title: "Some Title", - subtitle: None, -}, -ExplicitOption { - title: "Some Title", - subtitle: Some("Some Title"), -}, -// This won't compile: -// ExplicitOption { -// title: "Some Title", -// }, -} -
You can use #[props(default = 42)] to make a field optional and specify its default value:
--#![allow(unused)] -fn main() { -#[derive(PartialEq, Props)] -struct DefaultProps { - // default to 42 when not provided - #[props(default = 42)] - number: i64, -} - -fn DefaultComponent(cx: Scope<DefaultProps>) -> Element { - cx.render(rsx!(h1 { "{cx.props.number}" })) -} -} -
Then, similarly to optional props, you don't have to provide it:
---#![allow(unused)] -fn main() { -DefaultComponent { - number: 5, -}, -DefaultComponent {}, -} -
.intoIt is common for Rust functions to accept impl Into<SomeType> rather than just SomeType to support a wider range of parameters. If you want similar functionality with props, you can use #[props(into)]. For example, you could add it on a String prop – and &str will also be automatically accepted, as it can be converted into String:
--#![allow(unused)] -fn main() { -#[derive(PartialEq, Props)] -struct IntoProps { - #[props(into)] - string: String, -} - -fn IntoComponent(cx: Scope<IntoProps>) -> Element { - cx.render(rsx!(h1 { "{cx.props.string}" })) -} -} -
Then, you can use it so:
---#![allow(unused)] -fn main() { -IntoComponent { - string: "some &str", -}, -} -
inline_props macroSo far, every Component function we've seen had a corresponding ComponentProps struct to pass in props. This was quite verbose... Wouldn't it be nice to have props as simple function arguments? Then we wouldn't need to define a Props struct, and instead of typing cx.props.whatever, we could just use whatever directly!
inline_props allows you to do just that. Instead of typing the "full" version:
--#![allow(unused)] -fn main() { -#[derive(Props, PartialEq)] -struct TitleCardProps { - title: String, -} - -fn TitleCard(cx: Scope<TitleCardProps>) -> Element { - cx.render(rsx!{ - h1 { "{cx.props.title}" } - }) -} -} -
...you can define a function that accepts props as arguments. Then, just annotate it with #[inline_props], and the macro will turn it into a regular Component for you:
--#![allow(unused)] -fn main() { -#[inline_props] -fn TitleCard(cx: Scope, title: String) -> Element { - cx.render(rsx!{ - h1 { "{title}" } - }) -} -} -
-- -While the new Component is shorter and easier to read, this macro should not be used by library authors since you have less control over Prop documentation.
-
Just like you wouldn't want to write a complex program in a single, long, main function, you shouldn't build a complex UI in a single App function. Instead, you should break down the functionality of an app in logical parts called components.
A component is a Rust function, named in UpperCammelCase, that takes a Scope parameter and returns an Element describing the UI it wants to render. In fact, our App function is a component!
--#![allow(unused)] -fn main() { -// define a component that renders a div with the text "Hello, world!" -fn App(cx: Scope) -> Element { - cx.render(rsx! { - div { - "Hello, world!" - } - }) -} -} -
--You'll probably want to add
-#![allow(non_snake_case)]to the top of your crate to avoid warnings about UpperCammelCase component names
A Component is responsible for some rendering task – typically, rendering an isolated part of the user interface. For example, you could have an About component that renders a short description of Dioxus Labs:
--#![allow(unused)] -fn main() { -pub fn About(cx: Scope) -> Element { - cx.render(rsx!(p { - b {"Dioxus Labs"} - " An Open Source project dedicated to making Rust UI wonderful." - })) -} -} -
Then, you can render your component in another component, similarly to how elements are rendered:
---#![allow(unused)] -fn main() { -fn App(cx: Scope) -> Element { - cx.render(rsx! { - About {}, - About {}, - }) -} -} -

-- -At this point, it might seem like components are nothing more than functions. However, as you learn more about the features of Dioxus, you'll see that they are actually more powerful!
-
Dioxus is a declarative framework. This means that instead of telling Dioxus what to do (e.g. to "create an element" or "set the color to red") we simply declare what we want the UI to look like using RSX.
-You have already seen a simple example of RSX syntax in the "hello world" application:
---#![allow(unused)] -fn main() { -// define a component that renders a div with the text "Hello, world!" -fn App(cx: Scope) -> Element { - cx.render(rsx! { - div { - "Hello, world!" - } - }) -} -} -
Here, we use the rsx! macro to declare that we want a div element, containing the text "Hello, world!". Dioxus takes the RSX and constructs a UI from it.
RSX is very similar to HTML in that it describes elements with attributes and children. Here's an empty div element in RSX, as well as the resulting HTML:
--#![allow(unused)] -fn main() { -cx.render(rsx!(div { - // attributes / listeners - // children -})) -} -
<div></div>
-
-Attributes (and listeners) modify the behavior or appearance of the element they are attached to. They are specified inside the {} brackets, using the name: value syntax. You can provide the value as a literal in the RSX:
--#![allow(unused)] -fn main() { -cx.render(rsx!(a { - href: "https://www.youtube.com/watch?v=dQw4w9WgXcQ", - class: "primary_button", - color: "red", -})) -} -
<a href="https://www.youtube.com/watch?v=dQw4w9WgXcQ" class="primary_button" autofocus="true" style="color: red"></a>
-
---Note: All attributes defined in
-dioxus-htmlfollow the snake_case naming convention. They transform theirsnake_casenames to HTML'scamelCaseattributes.
--Note: Styles can be used directly outside of the
-style:attribute. In the above example,color: "red"is turned intostyle="color: red".
Dioxus has a pre-configured set of attributes that you can use. RSX is validated at compile time to make sure you didn't specify an invalid attribute. If you want to override this behavior with a custom attribute name, specify the attribute in quotes:
---#![allow(unused)] -fn main() { - cx.render(rsx!(b { - "customAttribute": "value", - })) -} -
<b customAttribute="value">
-</b>
-
-Similarly to how you can format Rust strings, you can also interpolate in RSX text. Use {variable} to Display the value of a variable in a string, or {variable:?} to use the Debug representation:
--#![allow(unused)] -fn main() { -let coordinates = (42, 0); -let country = "es"; -cx.render(rsx!(div { - class: "country-{country}", - "position": "{coordinates:?}", - // arbitrary expressions are allowed, - // as long as they don't contain `{}` - div { - "{country.to_uppercase()}" - }, - div { - "{7*6}" - }, - // {} can be escaped with {{}} - div { - "{{}}" - }, -})) -} -
<div class="country-es" position="(42, 0)">
- <div>ES</div>
- <div>42</div>
- <div>{}</div>
-</div>
-
-To add children to an element, put them inside the {} brackets after all attributes and listeners in the element. They can be other elements, text, or components. For example, you could have an ol (ordered list) element, containing 3 li (list item) elements, each of which contains some text:
--#![allow(unused)] -fn main() { -cx.render(rsx!(ol { - li {"First Item"} - li {"Second Item"} - li {"Third Item"} -})) -} -
<ol>
- <li>First Item</li>
- <li>Second Item</li>
- <li>Third Item</li>
-</ol>
-
-You can render multiple elements at the top level of rsx! and they will be automatically grouped.
--#![allow(unused)] -fn main() { -cx.render(rsx!( - p {"First Item"}, - p {"Second Item"}, -)) -} -
<p>First Item</p>
-<p>Second Item</p>
-
-You can include arbitrary Rust expressions as children within RSX that implements IntoDynNode. This is useful for displaying data from an iterator:
---#![allow(unused)] -fn main() { -let text = "Dioxus"; -cx.render(rsx!(span { - text.to_uppercase(), - // create a list of text from 0 to 9 - (0..10).map(|i| rsx!{ i.to_string() }) -})) -} -
<span>DIOXUS0123456789</span>
-
-In addition to iterators you can also use for loops directly within RSX:
---#![allow(unused)] -fn main() { -cx.render(rsx!{ - // use a for loop where the body itself is RSX - div { - // create a list of text from 0 to 9 - for i in 0..3 { - // NOTE: the body of the loop is RSX not a rust statement - div { - "{i}" - } - } - } - // iterator equivalent - div { - (0..3).map(|i| rsx!{ div { "{i}" } }) - } -}) -} -
<div>0</div>
-<div>1</div>
-<div>2</div>
-<div>0</div>
-<div>1</div>
-<div>2</div>
-
-You can also use if statements without an else branch within RSX:
---#![allow(unused)] -fn main() { -cx.render(rsx!{ - // use if statements without an else - if true { - rsx!(div { "true" }) - } -}) -} -
<div>true</div>
-
-
- While most attributes are simply passed on to the HTML, some have special behaviors.
-If you're working with pre-rendered assets, output from templates, or output from a JS library, then you might want to pass HTML directly instead of going through Dioxus. In these instances, reach for dangerous_inner_html.
For example, shipping a markdown-to-Dioxus converter might significantly bloat your final application size. Instead, you'll want to pre-render your markdown to HTML and then include the HTML directly in your output. We use this approach for the Dioxus homepage:
---#![allow(unused)] -fn main() { -// this should come from a trusted source -let contents = "live <b>dangerously</b>"; - -cx.render(rsx! { - div { - dangerous_inner_html: "{contents}", - } -}) -} -
--Note! This attribute is called "dangerous_inner_html" because it is dangerous to pass it data you don't trust. If you're not careful, you can easily expose cross-site scripting (XSS) attacks to your users.
-If you're handling untrusted input, make sure to sanitize your HTML before passing it into
-dangerous_inner_html– or just pass it to a Text Element to escape any HTML tags.
Most attributes, when rendered, will be rendered exactly as the input you provided. However, some attributes are considered "boolean" attributes and just their presence determines whether they affect the output. For these attributes, a provided value of "false" will cause them to be removed from the target element.
So this RSX wouldn't actually render the hidden attribute:
--#![allow(unused)] -fn main() { -cx.render(rsx! { - div { - hidden: "false", - "hello" - } -}) -} -
<div>hello</div>
-
-Not all attributes work like this however. Only the following attributes have this behavior:
-allowfullscreenallowpaymentrequestasyncautofocusautoplaycheckedcontrolsdefaultdeferdisabledformnovalidatehiddenismapitemscopeloopmultiplemutednomodulenovalidateopenplaysinlinereadonlyrequiredreversedselectedtruespeedFor any other attributes, a value of "false" will be sent directly to the DOM.
--This guide assumes you read the Web guide and installed the Dioxus-cli
-
For this guide, we're going to show how to use Dioxus with Axum, but dioxus-fullstack also integrates with the Warp and Salvo web frameworks.
Make sure you have Rust and Cargo installed, and then create a new project:
-cargo new --bin demo
-cd demo
-
-Add dioxus and dioxus-fullstack as dependencies:
cargo add dioxus
-cargo add dioxus-fullstack --features axum, ssr
-
-Next, add all the Axum dependencies. This will be different if you're using a different Web Framework
-cargo add tokio --features full
-cargo add axum
-
-Your dependencies should look roughly like this:
-[dependencies]
-axum = "*"
-dioxus = { version = "*" }
-dioxus-fullstack = { version = "*", features = ["axum", "ssr"] }
-tokio = { version = "*", features = ["full"] }
-
-Now, set up your Axum app to serve the Dioxus app.
--#![allow(non_snake_case, unused)] -use dioxus::prelude::*; - -#[tokio::main] -async fn main() { - #[cfg(feature = "ssr")] - { - use dioxus_fullstack::prelude::*; - - let addr = std::net::SocketAddr::from(([127, 0, 0, 1], 8080)); - axum::Server::bind(&addr) - .serve( - axum::Router::new() - .serve_dioxus_application("", ServeConfigBuilder::new(app, ())) - .into_make_service(), - ) - .await - .unwrap(); - } -} - -fn app(cx: Scope) -> Element { - let mut count = use_state(cx, || 0); - - cx.render(rsx! { - h1 { "High-Five counter: {count}" } - button { onclick: move |_| count += 1, "Up high!" } - button { onclick: move |_| count -= 1, "Down low!" } - }) -} -
Now, run your app with cargo run and open http://localhost:8080 in your browser. You should see a server-side rendered page with a counter.
Right now, the page is static. We can't interact with the buttons. To fix this, we can hydrate the page with dioxus-web.
First, modify your Cargo.toml to include two features, one for the server called ssr, and one for the client called web.
[dependencies]
-# Common dependancies
-dioxus = { version = "*" }
-dioxus-fullstack = { version = "*" }
-
-# Web dependancies
-dioxus-web = { version = "*", features=["hydrate"], optional = true }
-
-# Server dependancies
-axum = { version = "0.6.12", optional = true }
-tokio = { version = "1.27.0", features = ["full"], optional = true }
-
-[features]
-default = []
-ssr = ["axum", "tokio", "dioxus-fullstack/axum"]
-web = ["dioxus-web"]
-
-Next, we need to modify our main.rs to use either hydrate on the client or render on the server depending on the active features.
-#![allow(non_snake_case, unused)] -use dioxus::prelude::*; - -fn main() { - #[cfg(feature = "web")] - dioxus_web::launch_cfg(app, dioxus_web::Config::new().hydrate(true)); - #[cfg(feature = "ssr")] - { - use dioxus_fullstack::prelude::*; - tokio::runtime::Runtime::new() - .unwrap() - .block_on(async move { - let addr = std::net::SocketAddr::from(([127, 0, 0, 1], 8080)); - axum::Server::bind(&addr) - .serve( - axum::Router::new() - .serve_dioxus_application("", ServeConfigBuilder::new(app, ())) - .into_make_service(), - ) - .await - .unwrap(); - }); - } -} - -fn app(cx: Scope) -> Element { - let mut count = use_state(cx, || 0); - - cx.render(rsx! { - h1 { "High-Five counter: {count}" } - button { onclick: move |_| count += 1, "Up high!" } - button { onclick: move |_| count -= 1, "Down low!" } - }) -} -
Now, build your client-side bundle with dioxus build --features web and run your server with cargo run --features ssr. You should see the same page as before, but now you can interact with the buttons!
Let's make the initial count of the counter dynamic based on the current page.
-To do this, we must remove the serve_dioxus_application and replace it with a custom implementation of its four key functions:
-The only thing we need to change on the client is the props. dioxus-fullstack will automatically serialize the props it uses to server render the app and send them to the client. In the client section of main.rs, we need to add get_root_props_from_document to deserialize the props before we hydrate the app.
-#![allow(non_snake_case, unused)] -use dioxus::prelude::*; -use dioxus_fullstack::prelude::*; - -fn main() { - #[cfg(feature = "web")] - dioxus_web::launch_with_props( - app, - // Get the root props from the document - get_root_props_from_document().unwrap_or_default(), - dioxus_web::Config::new().hydrate(true), - ); - #[cfg(feature = "ssr")] - { - use axum::extract::Path; - use axum::extract::State; - use axum::routing::get; - tokio::runtime::Runtime::new() - .unwrap() - .block_on(async move { - let addr = std::net::SocketAddr::from(([127, 0, 0, 1], 8080)); - axum::Server::bind(&addr) - .serve( - axum::Router::new() - // Serve the dist folder with the static javascript and WASM files created by the dixous CLI - .serve_static_assets("./dist") - // Register server functions - .register_server_fns("") - // Connect to the hot reload server in debug mode - .connect_hot_reload() - // Render the application. This will serialize the root props (the intial count) into the HTML - .route( - "/", - get(move | State(ssr_state): State<SSRState>| async move { axum::body::Full::from( - ssr_state.render( - &ServeConfigBuilder::new( - app, - 0, - ) - .build(), - ) - )}), - ) - // Render the application with a different intial count - .route( - "/:initial_count", - get(move |Path(intial_count): Path<usize>, State(ssr_state): State<SSRState>| async move { axum::body::Full::from( - ssr_state.render( - &ServeConfigBuilder::new( - app, - intial_count, - ) - .build(), - ) - )}), - ) - .with_state(SSRState::default()) - .into_make_service(), - ) - .await - .unwrap(); - }); - } -} - -fn app(cx: Scope<usize>) -> Element { - let mut count = use_state(cx, || *cx.props); - - cx.render(rsx! { - h1 { "High-Five counter: {count}" } - button { onclick: move |_| count += 1, "Up high!" } - button { onclick: move |_| count -= 1, "Down low!" } - }) -} -
Now, build your client-side bundle with dioxus build --features web and run your server with cargo run --features ssr. Navigate to http://localhost:8080/1 and you should see the counter start at 1. Navigate to http://localhost:8080/2 and you should see the counter start at 2.
So far you have learned about three different approaches to target the web with Dioxus:
-Each approach has its tradeoffs:
-With Client side rendering, you send the entire content of your application to the client, and then the client generates all of the HTML of the page dynamically.
-This means that the page will be blank until the JavaScript bundle has loaded and the application has initialized. This can result in slower first render times and makes the page less SEO-friendly.
---SEO stands for Search Engine Optimization. It refers to the practice of making your website more likely to appear in search engine results. Search engines like Google and Bing use web crawlers to index the content of websites. Most of these crawlers are not able to run JavaScript, so they will not be able to index the content of your page if it is rendered client-side.
-
--Client-side rendering is a good starting point for most applications. It is well supported and makes it easy to communicate with the client/browser APIs
-
Liveview rendering communicates with the server over a WebSocket connection. It essentially moves all of the work that Client-side rendering does to the server.
-This makes it easy to communicate with the server, but more difficult to communicate with the client/browser APIS.
-Each interaction also requires a message to be sent to the server and back which can cause issues with latency.
-Because Liveview uses a websocket to render, the page will be blank until the WebSocket connection has been established and the first renderer has been sent form the websocket. Just like with client side rendering, this can make the page less SEO-friendly.
-Because the page is rendered on the server and the page is sent to the client piece by piece, you never need to send the entire application to the client. The initial load time can be faster than client-side rendering with large applications because Liveview only needs to send a constant small websocket script regardless of the size of the application.
---Liveview is a good fit for applications that already need to communicate with the server frequently (like real time collaborative apps), but don't need to communicate with as many client/browser APIs
-
--Server-side rendering is not a good fit for purely static sites like a blog
-
Each of these approaches has its tradeoffs. What if we could combine the best parts of each approach?
-We can achieve this by rendering the initial page on the server (SSR) and then taking over rendering on the client (Client-side rendering). Taking over rendering on the client is called hydration.
-Finally, we can use server functions to communicate with the server in a type-safe way.
-This approach uses both the dioxus-web and dioxus-ssr crates. To integrate those two packages and axum, warp, or salvo, Dioxus provides the dioxus-fullstack crate.
dixous-server provides server functions that allow you to call an automatically generated API on the server from the client as if it were a local function.
To make a server function, simply add the #[server(YourUniqueType)] attribute to a function. The function must:
Result with an error type of ServerFnErrorYou must call register on the type you passed into the server macro in your main function before starting your server to tell Dioxus about the server function.
Let's continue building on the app we made in the getting started guide. We will add a server function to our app that allows us to double the count on the server.
-First, add serde as a dependency:
-cargo add serde
-
-Next, add the server function to your main.rs:
-#![allow(non_snake_case, unused)] -use dioxus::prelude::*; -use dioxus_fullstack::prelude::*; - -fn main() { - #[cfg(feature = "web")] - dioxus_web::launch_with_props( - app, - // Get the root props from the document - get_root_props_from_document().unwrap_or_default(), - dioxus_web::Config::new().hydrate(true), - ); - #[cfg(feature = "ssr")] - { - use axum::extract::Path; - use axum::extract::State; - use axum::routing::get; - - // Register the server function before starting the server - DoubleServer::register().unwrap(); - - tokio::runtime::Runtime::new() - .unwrap() - .block_on(async move { - let addr = std::net::SocketAddr::from(([127, 0, 0, 1], 8080)); - axum::Server::bind(&addr) - .serve( - axum::Router::new() - // Serve the dist folder with the static javascript and WASM files created by the dixous CLI - .serve_static_assets("./dist") - // Register server functions - .register_server_fns("") - // Connect to the hot reload server in debug mode - .connect_hot_reload() - // Render the application. This will serialize the root props (the intial count) into the HTML - .route( - "/", - get(move |Path(intial_count): Path<usize>, State(ssr_state): State<SSRState>| async move { axum::body::Full::from( - ssr_state.render( - &ServeConfigBuilder::new( - app, - intial_count, - ) - .build(), - ) - )}), - ) - // Render the application with a different intial count - .route( - "/:initial_count", - get(move |Path(intial_count): Path<usize>, State(ssr_state): State<SSRState>| async move { axum::body::Full::from( - ssr_state.render( - &ServeConfigBuilder::new( - app, - intial_count, - ) - .build(), - ) - )}), - ) - .with_state(SSRState::default()) - .into_make_service(), - ) - .await - .unwrap(); - }); - } -} - -fn app(cx: Scope<usize>) -> Element { - let mut count = use_state(cx, || *cx.props); - - cx.render(rsx! { - h1 { "High-Five counter: {count}" } - button { onclick: move |_| count += 1, "Up high!" } - button { onclick: move |_| count -= 1, "Down low!" } - button { - onclick: move |_| { - to_owned![count]; - async move { - // Call the server function just like a local async function - if let Ok(new_count) = double_server(*count.current()).await { - count.set(new_count); - } - } - }, - "Double" - } - }) -} - -#[server(DoubleServer)] -async fn double_server(number: usize) -> Result<usize, ServerFnError> { - // Perform some expensive computation or access a database on the server - tokio::time::sleep(std::time::Duration::from_secs(1)).await; - let result = number * 2; - println!("server calculated {result}"); - Ok(result) -} -
Now, build your client-side bundle with dioxus build --features web and run your server with cargo run --features ssr. You should see a new button that multiplies the count by 2.
That's it! You've created a full-stack Dioxus app. You can find more examples of full-stack apps and information about how to integrate with other frameworks and desktop renderers in the dioxus-fullstack examples directory.
- -Build a standalone native desktop app that looks and feels the same across operating systems.
-Apps built with Dioxus are typically <5mb in size and use existing system resources, so they won't hog extreme amounts of RAM or memory.
-Examples:
- - -The desktop is a powerful target for Dioxus but is currently limited in capability when compared to the Web platform. Currently, desktop apps are rendered with the platform's WebView library, but your Rust code is running natively on a native thread. This means that browser APIs are not available, so rendering WebGL, Canvas, etc is not as easy as the Web. However, native system APIs are accessible, so streaming, WebSockets, filesystem, etc are all viable APIs. In the future, we plan to move to a custom web renderer-based DOM renderer with WGPU integrations.
-Dioxus Desktop is built off Tauri. Right now there aren't any Dioxus abstractions over the menubar, handling, etc, so you'll want to leverage Tauri – mostly Wry and Tao) directly.
-Dioxus desktop renders through a web view. Depending on your platform, you might need to install some dependancies.
-Windows Desktop apps depend on WebView2 – a library that should be installed in all modern Windows distributions. If you have Edge installed, then Dioxus will work fine. If you don't have Webview2, then you can install it through Microsoft. MS provides 3 options:
-For development purposes, use Option 1.
-Webview Linux apps require WebkitGtk. When distributing, this can be part of your dependency tree in your .rpm or .deb. However, likely, your users will already have WebkitGtk.
sudo apt install libwebkit2gtk-4.1-dev libgtk-3-dev libayatana-appindicator3-dev
-
-When using Debian/bullseye libappindicator3-dev is no longer available but replaced by libayatana-appindicator3-dev.
# on Debian/bullseye use:
-sudo apt install libwebkit2gtk-4.1-dev libgtk-3-dev libayatana-appindicator3-dev
-
-If you run into issues, make sure you have all the basics installed, as outlined in the Tauri docs.
-Currently – everything for macOS is built right in! However, you might run into an issue if you're using nightly Rust due to some permissions issues in our Tao dependency (which have been resolved but not published).
-Create a new crate:
-cargo new --bin demo
-cd demo
-
-Add Dioxus and the desktop renderer as dependencies (this will edit your Cargo.toml):
cargo add dioxus
-cargo add dioxus-desktop
-
-Edit your main.rs:
- -#![allow(non_snake_case)] -// import the prelude to get access to the `rsx!` macro and the `Scope` and `Element` types -use dioxus::prelude::*; - -fn main() { - // launch the dioxus app in a webview - dioxus_desktop::launch(App); -} - -// define a component that renders a div with the text "Hello, world!" -fn App(cx: Scope) -> Element { - cx.render(rsx! { - div { - "Hello, world!" - } - }) -} -
For the web renderer, you can use the dioxus cli to serve your application with hot reloading enabled.
-Install dioxus-cli. -Hot reloading is automatically enabled when using the web renderer on debug builds.
-dioxus serve --hot-reload
-
-For desktop, LiveView, and tui, you can place the hot reload macro at the top of your main function to enable hot reloading. -Hot reloading is automatically enabled on debug builds.
-For more information about hot reloading on native platforms and configuration options see the dioxus-hot-reload crate.
-Add the following to your main function:
--fn main() { - hot_reload_init!(); - // launch your application -} -
cargo run
-
-This section will help you set up your Dioxus project!
-Dioxus integrates very well with the Rust-Analyzer LSP plugin which will provide appropriate syntax highlighting, code navigation, folding, and more.
-Head over to https://rust-lang.org and install the Rust compiler.
-We strongly recommend going through the official Rust book completely. However, we hope that a Dioxus app can serve as a great first Rust project. With Dioxus, you'll learn about:
-We've put a lot of care into making Dioxus syntax familiar and easy to understand, so you won't need deep knowledge of async, lifetimes, or smart pointers until you start building complex Dioxus apps.
-Dioxus supports multiple platforms. Choose the platform you want to target below to get platform-specific setup instructions:
-Liveview allows apps to run on the server and render in the browser. It uses WebSockets to communicate between the server and the browser.
-Examples:
- -Liveview is currently limited in capability when compared to the Web platform. Liveview apps run on the server in a native thread. This means that browser APIs are not available, so rendering WebGL, Canvas, etc is not as easy as the Web. However, native system APIs are accessible, so streaming, WebSockets, filesystem, etc are all viable APIs.
-For this guide, we're going to show how to use Dioxus Liveview with Axum.
-Make sure you have Rust and Cargo installed, and then create a new project:
-cargo new --bin demo
-cd app
-
-Add Dioxus and the liveview renderer with the Axum feature as dependencies:
-cargo add dioxus
-cargo add dioxus-liveview --features axum
-
-Next, add all the Axum dependencies. This will be different if you're using a different Web Framework
-cargo add tokio --features full
-cargo add axum
-
-Your dependencies should look roughly like this:
-[dependencies]
-axum = "0.4.5"
-dioxus = { version = "*" }
-dioxus-liveview = { version = "*", features = ["axum"] }
-tokio = { version = "1.15.0", features = ["full"] }
-
-Now, set up your Axum app to respond on an endpoint.
--#[tokio::main] -async fn main() { - let addr: std::net::SocketAddr = ([127, 0, 0, 1], 3030).into(); - - let view = dioxus_liveview::LiveViewPool::new(); - - let app = Router::new() - // The root route contains the glue code to connect to the WebSocket - .route( - "/", - get(move || async move { - Html(format!( - r#" - <!DOCTYPE html> - <html> - <head> <title>Dioxus LiveView with Axum</title> </head> - <body> <div id="main"></div> </body> - {glue} - </html> - "#, - // Create the glue code to connect to the WebSocket on the "/ws" route - glue = dioxus_liveview::interpreter_glue(&format!("ws://{addr}/ws")) - )) - }), - ) - // The WebSocket route is what Dioxus uses to communicate with the browser - .route( - "/ws", - get(move |ws: WebSocketUpgrade| async move { - ws.on_upgrade(move |socket| async move { - // When the WebSocket is upgraded, launch the LiveView with the app component - _ = view.launch(dioxus_liveview::axum_socket(socket), app).await; - }) - }), - ); - - println!("Listening on http://{addr}"); - - axum::Server::bind(&addr.to_string().parse().unwrap()) - .serve(app.into_make_service()) - .await - .unwrap(); -} -
And then add our app component:
---#![allow(unused)] -fn main() { -fn app(cx: Scope) -> Element { - cx.render(rsx! { - div { - "Hello, world!" - } - }) -} -} -
And that's it!
- -Build a mobile app with Dioxus!
-Example: Todo App
-Mobile is currently the least-supported renderer target for Dioxus. Mobile apps are rendered with either the platform's WebView or experimentally through WGPU. WebView doesn't support animations, transparency, and native widgets.
-Mobile support is currently best suited for CRUD-style apps, ideally for internal teams who need to develop quickly but don't care much about animations or native widgets.
-This guide is primarily targeted at iOS apps, however, you can follow it while using the android guide in cargo-mobile.
Getting set up with mobile can be quite challenging. The tooling here isn't great (yet) and might take some hacking around to get things working. macOS M1 is broadly unexplored and might not work for you.
-We're going to be using cargo-mobile to build for mobile. First, install it:
cargo install --git https://github.com/BrainiumLLC/cargo-mobile
-
-And then initialize your app for the right platform. Use the winit template for now. Right now, there's no "Dioxus" template in cargo-mobile.
cargo mobile init
-
-We're going to completely clear out the dependencies it generates for us, swapping out winit with dioxus-mobile.
-[package]
-name = "dioxus-ios-demo"
-version = "0.1.0"
-authors = []
-edition = "2018"
-
-
-# leave the `lib` declaration
-[lib]
-crate-type = ["staticlib", "cdylib", "rlib"]
-
-
-# leave the binary it generates for us
-[[bin]]
-name = "dioxus-ios-demo-desktop"
-path = "gen/bin/desktop.rs"
-
-# clear all the dependencies
-[dependencies]
-mobile-entry-point = "0.1.0"
-dioxus = { version = "*"}
-dioxus-desktop = { version = "*" }
-simple_logger = "*"
-
-Edit your lib.rs:
- -use dioxus::prelude::*; - -fn main() { - dioxus_desktop::launch(app); -} - -fn app(cx: Scope) -> Element { - cx.render(rsx!{ - div { - "hello world!" - } - }) -} -
For lower-level control over the rendering process, you can use the dioxus-ssr crate directly. This can be useful when integrating with a web framework that dioxus-server does not support, or pre-rendering pages.
For this guide, we're going to show how to use Dioxus SSR with Axum.
-Make sure you have Rust and Cargo installed, and then create a new project:
-cargo new --bin demo
-cd demo
-
-Add Dioxus and the ssr renderer as dependencies:
-cargo add dioxus
-cargo add dioxus-ssr
-
-Next, add all the Axum dependencies. This will be different if you're using a different Web Framework
-cargo add tokio --features full
-cargo add axum
-
-Your dependencies should look roughly like this:
-[dependencies]
-axum = "0.4.5"
-dioxus = { version = "*" }
-dioxus-ssr = { version = "*" }
-tokio = { version = "1.15.0", features = ["full"] }
-
-Now, set up your Axum app to respond on an endpoint.
--#![allow(non_snake_case)] -use axum::{response::Html, routing::get, Router}; -// import the prelude to get access to the `rsx!` macro and the `Scope` and `Element` types -use dioxus::prelude::*; - -#[tokio::main] -async fn main() { - let addr = std::net::SocketAddr::from(([127, 0, 0, 1], 3000)); - println!("listening on http://{}", addr); - - axum::Server::bind(&addr) - .serve( - Router::new() - .route("/", get(app_endpoint)) - .into_make_service(), - ) - .await - .unwrap(); -} - -
And then add our endpoint. We can either render rsx! directly:
--#![allow(unused)] -fn main() { -async fn app_endpoint() -> Html<String> { - // render the rsx! macro to HTML - Html(dioxus_ssr::render_lazy(rsx! { - div { "hello world!" } - })) -} -} -
Or we can render VirtualDoms.
---#![allow(unused)] -fn main() { -async fn second_app_endpoint() -> Html<String> { - // create a component that renders a div with the text "hello world" - fn app(cx: Scope) -> Element { - cx.render(rsx!(div { "hello world" })) - } - // create a VirtualDom with the app component - let mut app = VirtualDom::new(app); - // rebuild the VirtualDom before rendering - let _ = app.rebuild(); - - // render the VirtualDom to HTML - Html(dioxus_ssr::render(&app)) -} -} -
And then add our app component:
---#![allow(unused)] -fn main() { -// define a component that renders a div with the text "Hello, world!" -fn App(cx: Scope) -> Element { - cx.render(rsx! { - div { - "Hello, world!" - } - }) -} -} -
And that's it!
-The Dioxus VirtualDom, sadly, is not currently Send. Internally, we use quite a bit of interior mutability which is not thread-safe.
-When working with web frameworks that require Send, it is possible to render a VirtualDom immediately to a String – but you cannot hold the VirtualDom across an await point. For retained-state SSR (essentially LiveView), you'll need to spawn a VirtualDom on its own thread and communicate with it via channels or create a pool of VirtualDoms.
-You might notice that you cannot hold the VirtualDom across an await point. Because Dioxus is currently not ThreadSafe, it must remain on the thread it started. We are working on loosening this requirement.
You can build a text-based interface that will run in the terminal using Dioxus.
-
--Note: this book was written with HTML-based platforms in mind. You might be able to follow along with TUI, but you'll have to adapt a bit.
-
TUI support is currently quite experimental. But, if you're willing to venture into the realm of the unknown, this guide will get you started.
-Start by making a new package and adding Dioxus and the TUI renderer as dependancies.
-cargo new --bin demo
-cd demo
-cargo add dioxus
-cargo add dioxus-tui
-
-Then, edit your main.rs with the basic template.
-#![allow(non_snake_case)] -// import the prelude to get access to the `rsx!` macro and the `Scope` and `Element` types -use dioxus::prelude::*; - -fn main() { - // launch the app in the terminal - dioxus_tui::launch(App); -} - -// create a component that renders a div with the text "Hello, world!" -fn App(cx: Scope) -> Element { - cx.render(rsx! { - div { - "Hello, world!" - } - }) -} -
To run our app:
-cargo run
-
-Press "ctrl-c" to close the app. To switch from "ctrl-c" to just "q" to quit you can launch the app with a configuration to disable the default quit and use the root TuiContext to quit on your own.
-- -// todo remove deprecated -#![allow(non_snake_case, deprecated)] - -use dioxus::events::{KeyCode, KeyboardEvent}; -use dioxus::prelude::*; -use dioxus_tui::TuiContext; - -fn main() { - dioxus_tui::launch_cfg( - App, - dioxus_tui::Config::new() - .without_ctrl_c_quit() - // Some older terminals only support 16 colors or ANSI colors - // If your terminal is one of these, change this to BaseColors or ANSI - .with_rendering_mode(dioxus_tui::RenderingMode::Rgb), - ); -} - -fn App(cx: Scope) -> Element { - let tui_ctx: TuiContext = cx.consume_context().unwrap(); - - cx.render(rsx! { - div { - width: "100%", - height: "10px", - background_color: "red", - justify_content: "center", - align_items: "center", - onkeydown: move |k: KeyboardEvent| if let KeyCode::Q = k.key_code { - tui_ctx.quit(); - }, - - "Hello world!" - } - }) -} -
Build single-page applications that run in the browser with Dioxus. To run on the Web, your app must be compiled to WebAssembly and depend on the dioxus and dioxus-web crates.
A build of Dioxus for the web will be roughly equivalent to the size of a React build (70kb vs 65kb) but it will load significantly faster because WebAssembly can be compiled as it is streamed.
-Examples:
- - ---Note: Because of the limitations of Wasm, not every crate will work with your web apps, so you'll need to make sure that your crates work without native system calls (timers, IO, etc).
-
The Web is the best-supported target platform for Dioxus.
-To develop your Dioxus app for the web, you'll need a tool to build and serve your assets. We recommend using dioxus-cli which includes a build system, Wasm optimization, a dev server, and support hot reloading:
-cargo install dioxus-cli
-
-Make sure the wasm32-unknown-unknown target for rust is installed:
rustup target add wasm32-unknown-unknown
-
-Create a new crate:
-cargo new --bin demo
-cd demo
-
-Add Dioxus and the web renderer as dependencies (this will edit your Cargo.toml):
cargo add dioxus
-cargo add dioxus-web
-
-Edit your main.rs:
-#![allow(non_snake_case)] -// import the prelude to get access to the `rsx!` macro and the `Scope` and `Element` types -use dioxus::prelude::*; - -fn main() { - // launch the web app - dioxus_web::launch(App); -} - -// create a component that renders a div with the text "Hello, world!" -fn App(cx: Scope) -> Element { - cx.render(rsx! { - div { - "Hello, world!" - } - }) -} -
And to serve our app:
-dioxus serve
-
-
- 
Dioxus is a portable, performant, and ergonomic framework for building cross-platform user interfaces in Rust. This guide will help you get started with writing Dioxus apps for the Web, Desktop, Mobile, and more.
---#![allow(unused)] -fn main() { -fn app(cx: Scope) -> Element { - let mut count = use_state(cx, || 0); - - cx.render(rsx!( - h1 { "High-Five counter: {count}" } - button { onclick: move |_| count += 1, "Up high!" } - button { onclick: move |_| count -= 1, "Down low!" } - )) -} -} -
Dioxus is heavily inspired by React. If you know React, getting started with Dioxus will be a breeze.
---This guide assumes you already know some Rust! If not, we recommend reading the book to learn Rust first.
-
Dioxus is a portable toolkit, meaning the Core implementation can run anywhere with no platform-dependent linking. Unlike many other Rust frontend toolkits, Dioxus is not intrinsically linked to WebSys. In fact, every element and event listener can be swapped out at compile time. By default, Dioxus ships with the html feature enabled, but this can be disabled depending on your target renderer.
Right now, we have several 1st-party renderers:
-Dioxus has not reached a stable release yet.
-Web: Since the web is a fairly mature platform, we expect there to be very little API churn for web-based features.
-Desktop: APIs will likely be in flux as we figure out better patterns than our ElectronJS counterpart.
-SSR: We don't expect the SSR API to change drastically in the future.
- -