Added initial_url to the router component (#510)

* added active_url

* renamed active_url to initial_url

* updated docs

packages/router/src/cfg.rs

@@ -2,4 +2,5 @@
 pub struct RouterCfg {
     pub base_url: Option<String>,
     pub active_class: Option<String>,
+    pub initial_url: Option<String>,
 }

packages/router/src/components/router.rs

@@ -28,6 +28,9 @@ pub struct RouterProps<'a> {
     /// This is useful if you don't want to repeat the same `active_class` prop value in every Link.
     /// By default set to `"active"`.
     pub active_class: Option<&'a str>,
+
+    /// Set the initial url.
+    pub initial_url: Option<String>,
 }
 
 /// A component that conditionally renders children based on the current location of the app.
@@ -43,6 +46,7 @@ pub fn Router<'a>(cx: Scope<'a, RouterProps<'a>>) -> Element {
             RouterCfg {
                 base_url: cx.props.base_url.map(|s| s.to_string()),
                 active_class: cx.props.active_class.map(|s| s.to_string()),
+                initial_url: cx.props.initial_url.clone(),
             },
         ))
     });

packages/router/src/service.rs

@@ -9,6 +9,7 @@ use std::{
     cell::{Cell, RefCell},
     collections::{HashMap, HashSet},
     rc::Rc,
+    str::FromStr,
     sync::Arc,
 };
 use url::Url;
@@ -84,7 +85,19 @@ impl RouterCore {
         #[cfg(not(feature = "web"))]
         let history = Box::new(hash::new());
 
-        let route = Arc::new(history.init_location());
+        let route = match &cfg.initial_url {
+            Some(url) => Arc::new(ParsedRoute {
+                url: Url::from_str(&url).expect(
+                    format!(
+                        "RouterCfg expects a valid initial_url, but got '{}'. Example: '{{scheme}}://{{?authority}}/{{?path}}'",
+                        &url
+                    ).as_str()
+                ),
+                title: None,
+                serialized_state: None,
+            }),
+            None => Arc::new(history.init_location()),
+        };
 
         let svc = Arc::new(Self {
             cfg,