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SvelteTemplate syntax

{#await ...}

{#await expression}...{:then name}...{:catch name}...{/await}
{#await expression}...{:then name}...{/await}
{#await expression then name}...{/await}
{#await expression catch name}...{/await}

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}

During server-side rendering, only the pending branch will be rendered.

If the provided expression is not a Promise only the :then branch will be rendered, including during server-side rendering.

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}

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}

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}

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