Macro yew::macros::html_nested
source · html_nested!() { /* proc-macro */ }
Expand description
This macro is similar to html!
, but preserves the component type instead
of wrapping it in Html
.
That macro is useful when, for example, in a typical implementation of a list
component (let’s assume it’s called List
).
In a typical implementation you might find two component types – List
and ListItem
.
Only ListItem
components are allowed to be children of List`.
You can find an example implementation of this in the nested_list
example.
That example shows, how to create static lists with their children.
use yew::html::ChildrenRenderer;
use yew::virtual_dom::VChild;
#[derive(Clone, Properties, PartialEq)]
struct ListProps {
children: ChildrenRenderer<ListItem>,
}
struct List;
impl Component for List {
type Properties = ListProps;
// ...
}
#[derive(Clone, PartialEq)]
struct ListItem;
impl Component for ListItem {
// ...
}
// Required for ChildrenRenderer
impl From<VChild<ListItem>> for ListItem {
fn from(child: VChild<ListItem>) -> Self {
Self
}
}
impl Into<Html> for ListItem {
fn into(self) -> Html {
html! { <self /> }
}
}
// You can use `List` with nested `ListItem` components.
// Using any other kind of element would result in a compile error.
html! {
<List>
<ListItem/>
<ListItem/>
<ListItem/>
</List>
}
// In many cases you might want to create the content dynamically.
// To do this, you can use the following code:
html! {
<List>
{ for some_iter.map(|_| html_nested!{ <ListItem/> }) }
</List>
}
If you used the html!
macro instead of html_nested!
, the code would
not compile because we explicitly indicated to the compiler that List
can only contain elements of type ListItem
using ChildrenRenderer<ListItem>
,
while html!
creates items of type Html
.