{#await ...}
{#await expression}...{:then name}...{:catch name}...{/await}
{#await expression}...{:then name}...{/await}
{#await expression then name}...{/await}
{#await expression catch name}...{/await}
Await 块允许你在 Promise
的三种可能状态上进行分支 - 待处理、已完成或已拒绝。
¥Await blocks allow you to branch on the three possible states of a Promise
— pending, fulfilled or rejected.
{#await promise}
<!-- promise is pending -->
<p>waiting for the promise to resolve...</p>
{:then value}
<!-- promise was fulfilled or not a Promise -->
<p>The value is {value}</p>
{:catch error}
<!-- promise was rejected -->
<p>Something went wrong: {error.message}</p>
{/await}
在服务器端渲染期间,只会渲染待处理的分支。
¥[!NOTE] During server-side rendering, only the pending branch will be rendered.
如果提供的表达式不是
Promise
,则只会渲染:then
分支,包括在服务器端渲染期间。¥If the provided expression is not a
Promise
, only the:then
branch will be rendered, including during server-side rendering.
如果在 promise 拒绝(或不可能出现错误)时不需要渲染任何内容,则可以省略 catch
块。
¥The catch
block can be omitted if you don’t need to render anything when the promise rejects (or no error is possible).
{#await promise}
<!-- promise is pending -->
<p>waiting for the promise to resolve...</p>
{:then value}
<!-- promise was fulfilled -->
<p>The value is {value}</p>
{/await}
如果你不关心挂起状态,你也可以省略初始块。
¥If you don’t care about the pending state, you can also omit the initial block.
{#await promise then value}
<p>The value is {value}</p>
{/await}
类似地,如果你只想显示错误状态,则可以省略 then
块。
¥Similarly, if you only want to show the error state, you can omit the then
block.
{#await promise catch error}
<p>The error is {error}</p>
{/await}
你可以将
#await
与import(...)
一起使用以延迟渲染组件:¥[!NOTE] You can use
#await
withimport(...)
to render components lazily:
> {#await import('./Component.svelte') then { default: Component }}
> <Component />
> {/await}
> ```