chore: rename ctx to cx

This commit is contained in:
Jonathan Kelley committed 2021-06-25 21:15:33 -04:00
1 parent 23c14078bb
commit 81382e7044
99 files changed
+789 -664

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+3 -3
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@@ -8,9 +8,9 @@ struct MyProps {
name: String
}
fn Example(ctx: Context<MyProps>) -> VNode {
ctx.render(html! {
<div> "Hello {ctx.name}!" </div>
fn Example(cx: Context<MyProps>) -> VNode {
cx.render(html! {
<div> "Hello {cx.name}!" </div>
})
}
```
+3 -3
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@@ -11,7 +11,7 @@ This macro allows allows a classic struct definition to be embedded directly int
```rust
// Inlines and destructure props *automatically*
#[functional_component]
fn Example(ctx: Context, name: &str, pending: bool, count: i32 ) -> VNode {
fn Example(cx: Context, name: &str, pending: bool, count: i32 ) -> VNode {
html! {
<div>
<p> "Hello, {name}!" </p>
@@ -32,10 +32,10 @@ struct ExampleProps {
count: i32
};
fn Example(ctx: &mut Context<ExampleProps>) -> VNode {
fn Example(cx: &mut Context<ExampleProps>) -> VNode {
let ExampleProps {
name, pending, count
} = ctx.props;
} = cx.props;
rsx! {
<div>
+11 -11
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@@ -12,8 +12,8 @@ You'll want to write RSX where you can, and in a future release we'll have a too
```rust
#[fc]
fn Example(ctx: Context, name: &str, pending: bool, count: i32 ) -> VNode {
ctx.render(html! {
fn Example(cx: Context, name: &str, pending: bool, count: i32 ) -> VNode {
cx.render(html! {
<div>
<p> "Hello, {name}!" </p>
<p> "Status: {pending}!" </p>
@@ -33,8 +33,8 @@ It's also a bit easier on the eyes 🙂.
```rust
#[fc]
fn Example(ctx: Context, name: &str, pending: bool, count: i32 ) -> VNode {
ctx.render(rsx! {
fn Example(cx: Context, name: &str, pending: bool, count: i32 ) -> VNode {
cx.render(rsx! {
div {
p {"Hello, {name}!"}
p {"Status: {pending}!"}
@@ -58,11 +58,11 @@ Commas are entirely optional, but might be useful to delineate between elements
The `render` function provides an **extremely efficient** allocator for VNodes and text, so try not to use the `format!` macro in your components. Rust's default `ToString` methods pass through the global allocator, but all text in components is allocated inside a manually-managed Bump arena.
```rust
static Example: FC<()> = |ctx| {
static Example: FC<()> = |cx| {
let text = "example";
ctx.render(rsx!{
cx.render(rsx!{
div {
h1 { "Example" },
@@ -114,9 +114,9 @@ static Example: FC<()> = |ctx| {
// rsx! is lazy, and the underlying closures cannot have the same type
// Rendering produces the VNode type
{match rand::gen_range::<i32>(1..3) {
1 => rsx!(in ctx, h1 { "big" })
2 => rsx!(in ctx, h2 { "medium" })
_ => rsx!(in ctx, h3 { "small" })
1 => rsx!(in cx, h1 { "big" })
2 => rsx!(in cx, h2 { "medium" })
_ => rsx!(in cx, h3 { "small" })
}}
// Optionals
@@ -127,12 +127,12 @@ static Example: FC<()> = |ctx| {
// Child nodes
// Returns &[VNode]
{ctx.children()}
{cx.children()}
// Duplicating nodes
// Clones the nodes by reference, so they are literally identical
{{
let node = rsx!(in ctx, h1{ "TopNode" });
let node = rsx!(in cx, h1{ "TopNode" });
(0..10).map(|_| node.clone())
}}
+6 -7
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@@ -1,17 +1,16 @@
```rust
fn Example(ctx: &mut Context<()>) -> VNode {
let service = use_combubulator(ctx);
fn Example(cx: &mut Context<()>) -> VNode {
let service = use_combubulator(cx);
let Status { name, pending, count } = service.info();
html! {
<div>
html! {
<div>
<p> "Hello, {name}!" </p>
<p> "Status: {pending}!" </p>
<p> "Count {count}!" </p>
<button onclick=|_| service.update()>
<button onclick=|_| service.update()>
"Refresh services"
</button>
</div>
</div>
}
}
```
+15 -17
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@@ -1,47 +1,45 @@
# Context API
```rust
// Create contexts available to children
// Only one context can be associated with any given component
// This is known as "exposed state". Children can access this context,
// but will not be automatically subscribed.
fn ContextCreate(ctx: &mut Context<()>) -> VNode {
let context = ctx.set_context(|| CustomContext::new());
html! { <> {ctx.children()} </> }
fn ContextCreate(cx: &mut Context<()>) -> VNode {
let context = cx.set_context(|| CustomContext::new());
html! { <> {cx.children()} </> }
}
fn ContextRead(ctx: &mut Context<()>) -> VNode {
fn ContextRead(cx: &mut Context<()>) -> VNode {
// Panics if context is not available
let some_ctx = ctx.get_context::<CustomContext>();
let text = some_ctx.select("some_selector");
let some_cx = cx.get_context::<CustomContext>();
let text = some_cx.select("some_selector");
html! { <div> "{text}" </div> }
}
fn Subscription(ctx: &mut Context<()>) -> VNode {
fn Subscription(cx: &mut Context<()>) -> VNode {
// Open a "port" on the component for actions to trigger a re-evaluation
let subscription = ctx.new_subscription();
let subscription = cx.new_subscription();
// A looping timer - the effect is re-called on every re-evaluation
use_async_effect(ctx, move || async {
use_async_effect(cx, move || async {
timer::new(2000).await;
subscription.call();
}, None);
// A one-shot timer, the deps don't change so the effect only happens once
use_async_effect_deps(ctx, move || async {
use_async_effect_deps(cx, move || async {
timer::new(2000).await;
subscription.call();
}, ());
}
// Mix subscriptions and context to make a simple Redux
fn use_global_state<T: UserContextTrait>(ctx: &mut Context<()>) -> T {
let some_ctx = ctx.get_context::<T>();
let component_subscription = ctx.new_subscription();
some_ctx.subscribe_component(component_subscription);
some_ctx
fn use_global_state<T: UserContextTrait>(cx: &mut Context<()>) -> T {
let some_cx = cx.get_context::<T>();
let component_subscription = cx.new_subscription();
some_cx.subscribe_component(component_subscription);
some_cx
}
```
+7 -11
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@@ -1,11 +1,11 @@
# Subscriptions
# Subscriptions
Yew subscriptions are used to schedule update for components into the future. The `Context` object can create subscriptions:
```rust
fn Component(ctx: Component<()>) -> VNode {
let update = ctx.schedule();
fn Component(cx: Component<()>) -> VNode {
let update = cx.schedule();
// Now, when the subscription is called, the component will be re-evaluted
update.consume();
}
@@ -13,16 +13,15 @@ fn Component(ctx: Component<()>) -> VNode {
Whenever a component's subscription is called, the component will then re-evaluated. You can consider the input properties of
a component to be just another form of subscription. By default, the Dioxus component system automatically diffs a component's props
when the parent function is called, and if the props are different, the child component's subscription is called.
when the parent function is called, and if the props are different, the child component's subscription is called.
The subscription API exposes this functionality allowing hooks and state management solutions the ability to update components whenever
some state or event occurs outside of the component. For instance, the `use_context` hook uses this to subscribe components that use a
particular context.
```rust
fn use_context<I>(ctx: Context<T>) -> I {
fn use_context<I>(cx: Context<T>) -> I {
}
@@ -32,6 +31,3 @@ fn use_context<I>(ctx: Context<T>) -> I {
```
+11 -13
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@@ -5,14 +5,15 @@ Concurrent mode provides a mechanism for building efficient asynchronous compone
To make a component asynchronous, simply change its function signature to async.
```rust
fn Example(ctx: Context<()>) -> Vnode {
fn Example(cx: Context<()>) -> Vnode {
rsx!{ <div> "Hello world!" </div> }
}
```
becomes
```rust
async fn Example(ctx: Context<()>) -> Vnode {
async fn Example(cx: Context<()>) -> Vnode {
rsx!{ <div> "Hello world!" </div> }
}
```
@@ -20,7 +21,7 @@ async fn Example(ctx: Context<()>) -> Vnode {
Now, logic in components can be awaited to delay updates of the component and its children. Like so:
```rust
async fn Example(ctx: Context<()>) -> Vnode {
async fn Example(cx: Context<()>) -> Vnode {
let name = fetch_name().await;
rsx!{ <div> "Hello {name}" </div> }
}
@@ -30,7 +31,7 @@ async fetch_name() -> String {
}
```
This component will only schedule its render once the fetch is complete. However, we *don't* recommend using async/await directly in your components.
This component will only schedule its render once the fetch is complete. However, we _don't_ recommend using async/await directly in your components.
Async is a notoriously challenging yet rewarding tool for efficient tools. If not careful, locking and unlocking shared aspects of the component's context can lead to data races and panics. If a shared resource is locked while the component is awaiting, then other components can be locked or panic when trying to access the same resource. These rules are especially important when references to shared global state are accessed using the context object's lifetime. If mutable references to data captured immutably by the context are taken, then the component will panic, and cause confusion.
@@ -39,7 +40,7 @@ Instead, we suggest using hooks and future combinators that can safely utilize t
As part of our Dioxus hooks crate, we provide a data loader hook which pauses a component until its async dependencies are ready. This caches requests, reruns the fetch if dependencies have changed, and provides the option to render something else while the component is loading.
```rust
async fn ExampleLoader(ctx: Context<()>) -> Vnode {
async fn ExampleLoader(cx: Context<()>) -> Vnode {
/*
Fetch, pause the component from rendering at all.
@@ -49,8 +50,8 @@ async fn ExampleLoader(ctx: Context<()>) -> Vnode {
This API stores the result on the Context object, so the loaded data is taken as reference.
*/
let name: &Result<SomeStructure> = use_fetch_data("http://example.com/json", ())
.place_holder(|ctx| rsx!{<div> "loading..." </div>})
.delayed_place_holder(1000, |ctx| rsx!{ <div> "still loading..." </div>})
.place_holder(|cx| rsx!{<div> "loading..." </div>})
.delayed_place_holder(1000, |cx| rsx!{ <div> "still loading..." </div>})
.await;
match name {
@@ -60,14 +61,11 @@ async fn ExampleLoader(ctx: Context<()>) -> Vnode {
}
```
```rust
async fn Example(ctx: Context<()>) -> VNode {
async fn Example(cx: Context<()>) -> VNode {
// Diff this set between the last set
// Check if we have any outstanding tasks?
//
//
// Eventually, render the component into the VDOM when the future completes
<div>
<Example />
@@ -79,6 +77,6 @@ async fn Example(ctx: Context<()>) -> VNode {
<Suspense placeholder={html!{<div>"Loading"</div>}}>
<Example />
</Suspense>
</div>
</div>
}
```
+9 -9
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@@ -2,13 +2,13 @@
Dioxus differs slightly from other UI virtual doms in some subtle ways due to its memory allocator.
One important aspect to understand is how props are passed down from parent components to children. All "components" (custom user-made UI elements) are tightly allocated together in an arena. However, because props and hooks are generically typed, they are casted to any and allocated on the heap - not in the arena with the components.
One important aspect to understand is how props are passed down from parent components to children. All "components" (custom user-made UI elements) are tightly allocated together in an arena. However, because props and hooks are generically typed, they are casted to any and allocated on the heap - not in the arena with the components.
With this system, we try to be more efficient when leaving the component arena and entering the heap. By default, props are memoized between renders using COW and context. This makes props comparisons fast - done via ptr comparisons on the cow pointer. Because memoization is done by default, parent re-renders will *not* cascade to children if the child's props did not change.
With this system, we try to be more efficient when leaving the component arena and entering the heap. By default, props are memoized between renders using COW and context. This makes props comparisons fast - done via ptr comparisons on the cow pointer. Because memoization is done by default, parent re-renders will _not_ cascade to children if the child's props did not change.
https://dmitripavlutin.com/use-react-memo-wisely/
This behavior is defined as an implicit attribute to user components. When in React land you might wrap a component is `react.memo`, Dioxus components are automatically memoized via an implicit attribute. You can manually configure this behavior on any component with "nomemo" to disable memoization.
This behavior is defined as an implicit attribute to user components. When in React land you might wrap a component is `react.memo`, Dioxus components are automatically memoized via an implicit attribute. You can manually configure this behavior on any component with "nomemo" to disable memoization.
```rust
fn test() -> VNode {
@@ -21,9 +21,9 @@ fn test() -> VNode {
}
}
static TestComponent: FC<()> = |ctx| html!{<div>"Hello world"</div>};
static TestComponent: FC<()> = |cx| html!{<div>"Hello world"</div>};
static TestComponent: FC<()> = |ctx| {
static TestComponent: FC<()> = |cx| {
let g = "BLAH";
html! {
<div> "Hello world" </div>
@@ -31,7 +31,7 @@ static TestComponent: FC<()> = |ctx| {
};
#[functional_component]
static TestComponent: FC<{ name: String }> = |ctx| html! { <div> "Hello {name}" </div> };
static TestComponent: FC<{ name: String }> = |cx| html! { <div> "Hello {name}" </div> };
```
## Why this behavior?
@@ -41,8 +41,8 @@ static TestComponent: FC<{ name: String }> = |ctx| html! { <div> "Hello {name}"
Take a component likes this:
```rust
fn test(ctx: Context<()>) -> VNode {
let Bundle { alpha, beta, gamma } = use_context::<SomeContext>(ctx);
fn test(cx: Context<()>) -> VNode {
let Bundle { alpha, beta, gamma } = use_context::<SomeContext>(cx);
html! {
<div>
<Component name=alpha />
@@ -53,4 +53,4 @@ fn test(ctx: Context<()>) -> VNode {
}
```
While the contents of the destructued bundle might change, not every child component will need to be re-rendered.
While the contents of the destructued bundle might change, not every child component will need to be re-rendered.