feat: add OptionalParamSegment (closes #2896) (#3140)

examples/hackernews/src/lib.rs

@@ -4,7 +4,7 @@ mod routes;
 use leptos_meta::{provide_meta_context, Link, Meta, Stylesheet};
 use leptos_router::{
     components::{FlatRoutes, Route, Router, RoutingProgress},
-    ParamSegment, StaticSegment,
+    OptionalParamSegment, ParamSegment, StaticSegment,
 };
 use routes::{nav::*, stories::*, story::*, users::*};
 use std::time::Duration;
@@ -28,9 +28,7 @@ pub fn App() -> impl IntoView {
                 <FlatRoutes fallback=|| "Not found.">
                     <Route path=(StaticSegment("users"), ParamSegment("id")) view=User/>
                     <Route path=(StaticSegment("stories"), ParamSegment("id")) view=Story/>
-                    <Route path=ParamSegment("stories") view=Stories/>
-                    // TODO allow optional params without duplication
-                    <Route path=StaticSegment("") view=Stories/>
+                    <Route path=OptionalParamSegment("stories") view=Stories/>
                 </FlatRoutes>
             </main>
         </Router>

examples/hackernews_axum/src/lib.rs

@@ -4,7 +4,7 @@ mod routes;
 use leptos_meta::{provide_meta_context, Link, Meta, MetaTags, Stylesheet};
 use leptos_router::{
     components::{FlatRoutes, Route, Router, RoutingProgress},
-    ParamSegment, StaticSegment,
+    OptionalParamSegment, ParamSegment, StaticSegment,
 };
 use routes::{nav::*, stories::*, story::*, users::*};
 use std::time::Duration;
@@ -46,9 +46,7 @@ pub fn App() -> impl IntoView {
                 <FlatRoutes fallback=|| "Not found.">
                     <Route path=(StaticSegment("users"), ParamSegment("id")) view=User/>
                     <Route path=(StaticSegment("stories"), ParamSegment("id")) view=Story/>
-                    <Route path=ParamSegment("stories") view=Stories/>
-                    // TODO allow optional params without duplication
-                    <Route path=StaticSegment("") view=Stories/>
+                    <Route path=OptionalParamSegment("stories") view=Stories/>
                 </FlatRoutes>
             </main>
         </Router>

examples/hackernews_islands_axum/src/lib.rs

@@ -4,7 +4,7 @@ mod routes;
 use leptos_meta::{provide_meta_context, Link, Meta, MetaTags, Stylesheet};
 use leptos_router::{
     components::{FlatRoutes, Route, Router},
-    ParamSegment, StaticSegment,
+    OptionalParamSegment, ParamSegment, StaticSegment,
 };
 use routes::{nav::*, stories::*, story::*, users::*};
 #[cfg(feature = "ssr")]
@@ -42,9 +42,7 @@ pub fn App() -> impl IntoView {
                 <FlatRoutes fallback=|| "Not found.">
                     <Route path=(StaticSegment("users"), ParamSegment("id")) view=User/>
                     <Route path=(StaticSegment("stories"), ParamSegment("id")) view=Story/>
-                    <Route path=ParamSegment("stories") view=Stories/>
-                    // TODO allow optional params without duplication
-                    <Route path=StaticSegment("") view=Stories/>
+                    <Route path=OptionalParamSegment("stories") view=Stories/>
                 </FlatRoutes>
             </main>
         </Router>

examples/hackernews_js_fetch/src/lib.rs

@@ -4,7 +4,7 @@ mod routes;
 use leptos_meta::{provide_meta_context, Link, Meta, MetaTags, Stylesheet};
 use leptos_router::{
     components::{FlatRoutes, Route, Router, RoutingProgress},
-    ParamSegment, StaticSegment,
+    OptionalParamSegment, ParamSegment, StaticSegment,
 };
 use routes::{nav::*, stories::*, story::*, users::*};
 use std::time::Duration;
@@ -46,9 +46,7 @@ pub fn App() -> impl IntoView {
                 <FlatRoutes fallback=|| "Not found.">
                     <Route path=(StaticSegment("users"), ParamSegment("id")) view=User/>
                     <Route path=(StaticSegment("stories"), ParamSegment("id")) view=Story/>
-                    <Route path=ParamSegment("stories") view=Stories/>
-                    // TODO allow optional params without duplication
-                    <Route path=StaticSegment("") view=Stories/>
+                    <Route path=OptionalParamSegment("stories") view=Stories/>
                 </FlatRoutes>
             </main>
         </Router>

integrations/actix/src/lib.rs

@@ -35,7 +35,7 @@ use leptos_router::{
     components::provide_server_redirect,
     location::RequestUrl,
     static_routes::{RegenerationFn, ResolvedStaticPath},
-    Method, PathSegment, RouteList, RouteListing, SsrMode,
+    ExpandOptionals, Method, PathSegment, RouteList, RouteListing, SsrMode,
 };
 use once_cell::sync::Lazy;
 use parking_lot::RwLock;
@@ -901,7 +901,7 @@ trait ActixPath {
     fn to_actix_path(&self) -> String;
 }
 
-impl ActixPath for &[PathSegment] {
+impl ActixPath for Vec<PathSegment> {
     fn to_actix_path(&self) -> String {
         let mut path = String::new();
         for segment in self.iter() {
@@ -923,6 +923,14 @@ impl ActixPath for &[PathSegment] {
                     path.push_str(":.*}");
                 }
                 PathSegment::Unit => {}
+                PathSegment::OptionalParam(_) => {
+                    #[cfg(feature = "tracing")]
+                    tracing::error!(
+                        "to_axum_path should only be called on expanded \
+                         paths, which do not have OptionalParam any longer"
+                    );
+                    Default::default()
+                }
             }
         }
         path
@@ -938,23 +946,34 @@ pub struct ActixRouteListing {
     regenerate: Vec<RegenerationFn>,
 }
 
-impl From<RouteListing> for ActixRouteListing {
-    fn from(value: RouteListing) -> Self {
-        let path = value.path().to_actix_path();
-        let path = if path.is_empty() {
-            "/".to_string()
-        } else {
-            path
-        };
-        let mode = value.mode();
-        let methods = value.methods().collect();
-        let regenerate = value.regenerate().into();
-        Self {
-            path,
-            mode: mode.clone(),
-            methods,
-            regenerate,
-        }
+trait IntoRouteListing: Sized {
+    fn into_route_listing(self) -> Vec<ActixRouteListing>;
+}
+
+impl IntoRouteListing for RouteListing {
+    fn into_route_listing(self) -> Vec<ActixRouteListing> {
+        self.path()
+            .to_vec()
+            .expand_optionals()
+            .into_iter()
+            .map(|path| {
+                let path = path.to_actix_path();
+                let path = if path.is_empty() {
+                    "/".to_string()
+                } else {
+                    path
+                };
+                let mode = self.mode();
+                let methods = self.methods().collect();
+                let regenerate = self.regenerate().into();
+                ActixRouteListing {
+                    path,
+                    mode: mode.clone(),
+                    methods,
+                    regenerate,
+                }
+            })
+            .collect()
     }
 }
 
@@ -1033,7 +1052,7 @@ where
     let mut routes = routes
         .into_inner()
         .into_iter()
-        .map(ActixRouteListing::from)
+        .flat_map(IntoRouteListing::into_route_listing)
         .collect::<Vec<_>>();
 
     (

integrations/axum/src/lib.rs

@@ -66,7 +66,7 @@ use leptos_router::{
     components::provide_server_redirect,
     location::RequestUrl,
     static_routes::{RegenerationFn, StaticParamsMap},
-    PathSegment, RouteList, RouteListing, SsrMode,
+    ExpandOptionals, PathSegment, RouteList, RouteListing, SsrMode,
 };
 #[cfg(feature = "default")]
 use once_cell::sync::Lazy;
@@ -1267,23 +1267,34 @@ pub struct AxumRouteListing {
     regenerate: Vec<RegenerationFn>,
 }
 
-impl From<RouteListing> for AxumRouteListing {
-    fn from(value: RouteListing) -> Self {
-        let path = value.path().to_axum_path();
-        let path = if path.is_empty() {
-            "/".to_string()
-        } else {
-            path
-        };
-        let mode = value.mode();
-        let methods = value.methods().collect();
-        let regenerate = value.regenerate().into();
-        Self {
-            path,
-            mode: mode.clone(),
-            methods,
-            regenerate,
-        }
+trait IntoRouteListing: Sized {
+    fn into_route_listing(self) -> Vec<AxumRouteListing>;
+}
+
+impl IntoRouteListing for RouteListing {
+    fn into_route_listing(self) -> Vec<AxumRouteListing> {
+        self.path()
+            .to_vec()
+            .expand_optionals()
+            .into_iter()
+            .map(|path| {
+                let path = path.to_axum_path();
+                let path = if path.is_empty() {
+                    "/".to_string()
+                } else {
+                    path
+                };
+                let mode = self.mode();
+                let methods = self.methods().collect();
+                let regenerate = self.regenerate().into();
+                AxumRouteListing {
+                    path,
+                    mode: mode.clone(),
+                    methods,
+                    regenerate,
+                }
+            })
+            .collect()
     }
 }
 
@@ -1367,7 +1378,7 @@ where
     let mut routes = routes
         .into_inner()
         .into_iter()
-        .map(AxumRouteListing::from)
+        .flat_map(IntoRouteListing::into_route_listing)
         .collect::<Vec<_>>();
 
     (
@@ -1700,7 +1711,7 @@ trait AxumPath {
     fn to_axum_path(&self) -> String;
 }
 
-impl AxumPath for &[PathSegment] {
+impl AxumPath for Vec<PathSegment> {
     fn to_axum_path(&self) -> String {
         let mut path = String::new();
         for segment in self.iter() {
@@ -1720,6 +1731,14 @@ impl AxumPath for &[PathSegment] {
                     path.push_str(s);
                 }
                 PathSegment::Unit => {}
+                PathSegment::OptionalParam(_) => {
+                    #[cfg(feature = "tracing")]
+                    tracing::error!(
+                        "to_axum_path should only be called on expanded \
+                         paths, which do not have OptionalParam any longer"
+                    );
+                    Default::default()
+                }
             }
         }
         path

router/src/flat_router.rs

@@ -1,11 +1,11 @@
 use crate::{
     hooks::Matched,
     location::{LocationProvider, Url},
-    matching::Routes,
+    matching::{MatchParams, Routes},
     params::ParamsMap,
     view_transition::start_view_transition,
-    ChooseView, MatchInterface, MatchNestedRoutes, MatchParams, PathSegment,
-    RouteList, RouteListing, RouteMatchId,
+    ChooseView, MatchInterface, MatchNestedRoutes, PathSegment, RouteList,
+    RouteListing, RouteMatchId,
 };
 use any_spawner::Executor;
 use either_of::Either;

router/src/matching/horizontal/mod.rs

@@ -1,5 +1,4 @@
 use super::{PartialPathMatch, PathSegment};
-use std::borrow::Cow;
 mod param_segments;
 mod static_segment;
 mod tuples;
@@ -13,12 +12,9 @@ pub use static_segment::*;
 /// as subsequent segments of the URL and tries to match them all. For a "vertical"
 /// matching that sees a tuple as alternatives to one another, see [`RouteChild`](super::RouteChild).
 pub trait PossibleRouteMatch {
-    type ParamsIter: IntoIterator<Item = (Cow<'static, str>, String)>;
+    const OPTIONAL: bool = false;
 
-    fn test<'a>(
-        &self,
-        path: &'a str,
-    ) -> Option<PartialPathMatch<'a, Self::ParamsIter>>;
+    fn test<'a>(&self, path: &'a str) -> Option<PartialPathMatch<'a>>;
 
     fn generate_path(&self, path: &mut Vec<PathSegment>);
 }