ДЗ smart-house-web завершено

smart-house-web/frontend/examples/3_10_children.rs

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+#![allow(non_snake_case, unused)]
+
+use leptos::prelude::*;
+
+// Often, you want to pass some kind of child view to another
+// component. There are two basic patterns for doing this:
+// - "render props": creating a component prop that takes a function
+//   that creates a view
+// - the `children` prop: a special property that contains content
+//   passed as the children of a component in your view, not as a
+//   property
+
+#[component]
+pub fn App() -> impl IntoView {
+    let (items, set_items) = signal(vec![0, 1, 2]);
+    let render_prop = move || {
+        let len = move || items.read().len();
+        view! {
+            <p>"Length: " {len}</p>
+        }
+    };
+
+    view! {
+        // This component just displays the two kinds of children,
+        // embedding them in some other markup
+        <TakesChildren
+            // for component props, you can shorthand
+            // `render_prop=render_prop` => `render_prop`
+            // (this doesn't work for HTML element attributes)
+            render_prop
+        >
+            // these look just like the children of an HTML element
+            <p>"Here's a child."</p>
+            <p>"Here's another child."</p>
+        </TakesChildren>
+        <hr/>
+        // This component actually iterates over and wraps the children
+        <WrapsChildren>
+            <p>"Here's a child."</p>
+            <p>"Here's another child."</p>
+        </WrapsChildren>
+    }
+}
+
+/// Displays a `render_prop` and some children within markup.
+#[component]
+pub fn TakesChildren<F, IV>(
+    /// Takes a function (type F) that returns anything that can be
+    /// converted into a View (type IV)
+    render_prop: F,
+    /// `children` takes the `Children` type
+    /// this is an alias for `Box<dyn FnOnce() -> Fragment>`
+    /// ... aren't you glad we named it `Children` instead?
+    children: Children,
+) -> impl IntoView
+where
+    F: Fn() -> IV,
+    IV: IntoView,
+{
+    view! {
+        <h1><code>"<TakesChildren/>"</code></h1>
+        <h2>"Render Prop"</h2>
+        {render_prop()}
+        <hr/>
+        <h2>"Children"</h2>
+        {children()}
+    }
+}
+
+/// Wraps each child in an `<li>` and embeds them in a `<ul>`.
+#[component]
+pub fn WrapsChildren(children: ChildrenFragment) -> impl IntoView {
+    // children() returns a `Fragment`, which has a
+    // `nodes` field that contains a Vec<View>
+    // this means we can iterate over the children
+    // to create something new!
+    let children = children()
+        .nodes
+        .into_iter()
+        .map(|child| view! { <li>{child}</li> })
+        .collect::<Vec<_>>();
+
+    view! {
+        <h1><code>"<WrapsChildren/>"</code></h1>
+        // wrap our wrapped children in a UL
+        <ul>{children}</ul>
+    }
+}
+
+fn main() {
+    leptos::mount::mount_to_body(App)
+}