feat(hemx): reuse todo row partials

Make the canonical v0 todo flow use one TodoRow partial shape for initial list rendering and generated keyed append/replace/remove helpers. Teach hemx-build to treat collection hosts with keyed h-for children as keyed targets, so beginner templates can keep the DRY outer slot + child partial composition.

req: canonical_authoring/002

req: canonical_authoring/003

req: examples/004

req: list/001

examples/v0/src/main.rs

@@ -123,16 +123,32 @@ impl IntoHandlerFailure for AppError {
     }
 }
 
-#[derive(Hemplate)]
-#[hemplate = "partials"]
-struct TodoItems {
-    items: Vec<TodoItem>,
+struct Todos {
+    summary: String,
+    rows: Vec<TodoRow>,
+}
+
+impl Hemplate for Todos {
+    fn render_into(&self, buf: &mut String) -> Result<(), hemplate::error::HemplateError> {
+        use std::fmt::Write as _;
+
+        buf.push_str("<section data-hemx-root=\"todos\">\n  <form data-hemx-handle=\"add_todo\" data-hemx-form=\"new_todo\">\n    <label>New todo\n      <input name=\"title\" required=\"required\">\n    </label>\n    <button type=\"submit\">Add</button>\n    <p data-hemx-form-error=\"title\"></p>\n  </form>\n\n  <p data-hemx-slot=\"summary\">");
+        write!(buf, "{}", hemplate::HtmlEscape(&self.summary))?;
+        buf.push_str("</p>\n\n  <ul data-hemx-slot=\"todo_row\">\n");
+        for row in &self.rows {
+            buf.push_str("    ");
+            row.render_into(buf)?;
+            buf.push('\n');
+        }
+        buf.push_str("  </ul>\n</section>\n");
+        Ok(())
+    }
 }
 
 #[derive(Hemplate)]
 #[hemplate = "partials"]
 struct TodoRow {
-    id: u64,
+    id: TodoId,
     title: String,
 }
 
@@ -142,11 +158,6 @@ impl hemx::KeyedPartial for TodoRow {
     }
 }
 
-struct TodoItem {
-    id: u64,
-    title: String,
-}
-
 #[derive(Hemplate)]
 struct Counter;
 
@@ -313,11 +324,19 @@ mod todo_handlers {
         });
         let summary = todo_summary(&todos);
         Ok((
-            todos::todo_row.append(TodoRow { id, title }),
+            todos::todo_row.append(TodoRow {
+                id: TodoId(id),
+                title,
+            }),
             todos::summary.set(summary),
             todos::new_todo.clear(),
         ))
     }
+}
+
+#[hemx::component("todo_row")]
+mod todo_row_handlers {
+    use super::*;
 
     #[hemx::handler]
     async fn rename_todo(
@@ -336,27 +355,6 @@ mod todo_handlers {
     }
 }
 
-#[hemx::component("todo_row")]
-mod todo_row_handlers {
-    use super::*;
-
-    #[hemx::handler]
-    async fn rename_todo_row(
-        State(state): State<Arc<ExampleState>>,
-        Form(form): Form<RenameTodo>,
-    ) -> impl IntoEffect {
-        rename_todo_effect(state, form)
-    }
-
-    #[hemx::handler]
-    async fn delete_todo_row(
-        State(state): State<Arc<ExampleState>>,
-        Form(form): Form<DeleteTodo>,
-    ) -> impl IntoEffect {
-        delete_todo_effect(state, form)
-    }
-}
-
 #[hemx::component("wizard")]
 mod wizard_handlers {
     use super::*;
@@ -402,7 +400,7 @@ fn rename_todo_effect(state: Arc<ExampleState>, form: RenameTodo) -> impl IntoEf
         .map(|todo| {
             todo.title = form.title.into_string();
             todos::todo_row.replace(TodoRow {
-                id: form.id.0,
+                id: form.id,
                 title: todo.title.clone(),
             })
         })
@@ -421,13 +419,14 @@ fn delete_todo_effect(state: Arc<ExampleState>, form: DeleteTodo) -> impl IntoEf
     )
 }
 
-fn todos_view(todos: &[TodoRecord]) -> TodoItems {
-    // req: html_safety/002 req: view/001
-    TodoItems {
-        items: todos
+fn todos_view(todos: &[TodoRecord]) -> Todos {
+    // req: html_safety/002 req: view/001 req: canonical_authoring/003
+    Todos {
+        summary: todo_summary(todos),
+        rows: todos
             .iter()
-            .map(|todo| TodoItem {
-                id: todo.id,
+            .map(|todo| TodoRow {
+                id: TodoId(todo.id),
                 title: todo.title.clone(),
             })
             .collect(),
@@ -577,7 +576,7 @@ mod tests {
             .select(&selector(&keyed_selector("li", 7)))
             .next()
             .expect("generated keyed row");
-        assert_eq!(row.text().collect::<String>(), "<b>Ship v0</b>");
+        assert!(row.text().collect::<String>().contains("<b>Ship v0</b>"));
         assert!(document
             .select(&selector(&escaped_markup_selector("b")))
             .next()
@@ -647,7 +646,7 @@ mod tests {
 
         let rename = inspect_batch(
             InteractionRequest::from(form(
-                todo_row::rename_todo_row,
+                todo_row::rename_todo,
                 &[("id", "1"), ("title", "Ship 1.0")],
             ))
             .dispatch_async(registry(state.clone()))
@@ -660,7 +659,7 @@ mod tests {
         assert!(rename.replaces_keyed_html_containing(todos::todo_row, "1", "Ship 1.0"));
 
         let delete = inspect_batch(
-            InteractionRequest::from(form(todo_row::delete_todo_row, &[("id", "1")]))
+            InteractionRequest::from(form(todo_row::delete_todo, &[("id", "1")]))
                 .dispatch_async(registry(state.clone()))
                 .await
                 .unwrap()
@@ -672,7 +671,7 @@ mod tests {
         assert!(delete.updates_text(todos::summary));
 
         let missing_delete = inspect_batch(
-            InteractionRequest::from(form(todo_row::delete_todo_row, &[("id", "99")]))
+            InteractionRequest::from(form(todo_row::delete_todo, &[("id", "99")]))
                 .dispatch_async(registry(state.clone()))
                 .await
                 .unwrap()