fix: run unmount logic for element children (closes #2832) (#2834)

tachys/src/html/element/mod.rs

@@ -443,12 +443,22 @@ impl<At, Ch, R: Renderer> Deref for ElementState<At, Ch, R> {
 
 impl<At, Ch, R> Mountable<R> for ElementState<At, Ch, R>
 where
+    Ch: Mountable<R>,
     R: Renderer,
 {
     fn unmount(&mut self) {
+        if let Some(children) = self.children.as_mut() {
+            children.unmount_from_parent();
+        }
         R::remove(self.el.as_ref());
     }
 
+    fn unmount_from_parent(&mut self) {
+        if let Some(children) = self.children.as_mut() {
+            children.unmount_from_parent();
+        }
+    }
+
     fn mount(&mut self, parent: &R::Element, marker: Option<&R::Node>) {
         R::insert_node(parent, self.el.as_ref(), marker);
     }

tachys/src/view/mod.rs

@@ -282,6 +282,15 @@ pub trait Mountable<R: Renderer> {
     /// Detaches the view from the DOM.
     fn unmount(&mut self);
 
+    /// Detaches the view from the DOM, when it is a child of another element that is being
+    /// unmounted.
+    ///
+    /// Most elements do not require any action here, but special view types that have additional
+    /// unmount logic do.
+    fn unmount_from_parent(&mut self) {
+        self.unmount();
+    }
+
     /// Mounts a node to the interface.
     fn mount(&mut self, parent: &R::Element, marker: Option<&R::Node>);
 

tachys/src/view/primitives.rs

@@ -27,6 +27,8 @@ macro_rules! render_primitive {
 						self.0.unmount()
 					}
 
+                    fn unmount_from_parent(&mut self) {}
+
 					fn mount(
 						&mut self,
 						parent: &<R as Renderer>::Element,

tachys/src/view/strings.rs

@@ -131,6 +131,8 @@ where
         self.node.unmount()
     }
 
+    fn unmount_from_parent(&mut self) {}
+
     fn mount(
         &mut self,
         parent: &<R as Renderer>::Element,
@@ -232,6 +234,8 @@ impl<R: Renderer> Mountable<R> for StringState<R> {
         self.node.unmount()
     }
 
+    fn unmount_from_parent(&mut self) {}
+
     fn mount(
         &mut self,
         parent: &<R as Renderer>::Element,
@@ -324,6 +328,8 @@ impl<R: Renderer> Mountable<R> for RcStrState<R> {
         self.node.unmount()
     }
 
+    fn unmount_from_parent(&mut self) {}
+
     fn mount(
         &mut self,
         parent: &<R as Renderer>::Element,
@@ -427,6 +433,8 @@ impl<R: Renderer> Mountable<R> for ArcStrState<R> {
         self.node.unmount()
     }
 
+    fn unmount_from_parent(&mut self) {}
+
     fn mount(
         &mut self,
         parent: &<R as Renderer>::Element,
@@ -530,6 +538,8 @@ impl<'a, R: Renderer> Mountable<R> for CowStrState<'a, R> {
         self.node.unmount()
     }
 
+    fn unmount_from_parent(&mut self) {}
+
     fn mount(
         &mut self,
         parent: &<R as Renderer>::Element,