docs: add document on adding class and other attributes to <A/> component

router/src/link.rs

@@ -66,6 +66,25 @@ where
 ///    This is helpful for accessibility and for styling. For example, maybe you want to set the link a
 ///    different color if it’s a link to the page you’re currently on.
 ///
+/// ### Additional Attributes
+///
+/// You can add additional HTML attributes to the `<a>` element created by this component using the attribute
+/// spreading syntax for components. For example, to add a class, you can use `attr:class="my-link"`.
+/// Alternately, you can add any number of HTML attributes (include `class`) after a `{..}` marker.
+///
+/// ```rust
+/// # use leptos::prelude::*; use leptos_router::components::A;
+/// # fn spread_example() -> impl IntoView {
+/// view! {
+///   <A href="/about" attr:class="my-link" {..} id="foo">"Some link"</A>
+///   <A href="/about" {..} class="my-link" id="bar">"Another link"</A>
+///   <A href="/about" {..} class:my-link=true id="baz">"One more"</A>
+/// }
+/// # }
+/// ```
+///
+/// For more information on this attribute spreading syntax, [see here](https://book.leptos.dev/view/03_components.html#spreading-attributes-onto-components).
+///
 /// ### DOM Properties
 ///
 /// `<a>` elements can take several additional DOM properties with special meanings.

tachys/src/html/class.rs

@@ -540,20 +540,11 @@ impl IntoClass for (&'static str, bool) {
     fn rebuild(self, state: &mut Self::State) {
         let (name, include) = self;
         let (class_list, prev_include, prev_name) = state;
-        if name == *prev_name {
-            if include != *prev_include {
-                if include {
-                    Rndr::add_class(class_list, name);
-                } else {
-                    Rndr::remove_class(class_list, name);
-                }
-            }
-        } else {
-            if *prev_include {
-                Rndr::remove_class(class_list, prev_name);
-            }
+        if include != *prev_include {
             if include {
                 Rndr::add_class(class_list, name);
+            } else {
+                Rndr::remove_class(class_list, name);
             }
         }
         *prev_include = include;

tachys/src/reactive_graph/class.rs

@@ -209,15 +209,6 @@ where
 
     fn rebuild(self, state: &mut Self::State) {
         let (name, mut f) = self;
-
-        let prev_name = state.name;
-        let prev_state = state.effect.take_value();
-        if let Some((list, prev_include)) = &prev_state {
-            if prev_name != name && *prev_include {
-                Rndr::remove_class(list, prev_name);
-            }
-        }
-
         // Name might've updated:
         state.name = name;
         let mut first_run = true;
@@ -241,7 +232,7 @@ where
                     }
                 }
             },
-            prev_state,
+            state.effect.take_value(),
         );
     }