> For the complete documentation index, see [llms.txt](https://exelord.gitbook.io/ember-await/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://exelord.gitbook.io/ember-await/api/arguments.md).

# Arguments

These can be passed to `<Await />` component.

* [`promise`](/ember-await/api/arguments.md#promise) An already started Promise instance or function that returns a Promise, automatically invoked..
* [`defer`](/ember-await/api/arguments.md#defer) Function that returns a Promise, manually invoked with `run`.
* [`initialValue`](/ember-await/api/arguments.md#initialvalue) Provide initial data or error for server-side rendering.
* [`onResolve`](/ember-await/api/arguments.md#onresolve) Callback invoked when Promise resolves.
* [`onReject`](/ember-await/api/arguments.md#onreject) Callback invoked when Promise rejects.
* [`onCancel`](/ember-await/api/arguments.md#oncancel) Callback invoked when a Promise is cancelled.

## `promise`

> `Promise | function(controller: AbortController): Promise`

A Promise instance which has already started or a function that returns a promise Changing the value of `promise` will cancel any pending promise and listen to the new one. The promise function is automatically invoked during component construction. If `promise` is initially undefined, the Ember Await state will be `pending`.

> Note that `reload` will not do anything when `promise` has been passed as property not a function.

## `defer`

> `function(args: any[], controller: AbortController): Promise`

A function that returns a promise. This is invoked only by manually calling `run(...args)`. The `defer` is commonly used to send data to the server following a user action, such as submitting a form. You can use this in conjunction with `promise` to fill the form with existing data, then updating it on submit with `defer`.

> Be aware that when using both `promise` and `defer`, the shape of their fulfilled value should match, because they both update the same `data`.

## `initialValue`

> `any | Error`

Initial state for `data` or `error` (if instance of Error); useful for server-side rendering. When an `initialValue` is provided, the `promise` will not be invoked on first render if it is a function. Instead, `status` will be immediately set to `fulfilled` or `rejected` and your components will render accordingly. If you want to trigger the `promise` regardless, you can call `reload()`.

> Note that `onResolve` or `onReject` is not invoked in this case.

## `onResolve`

> `function(data: any): void`

Callback function invoked when a promise resolves, receives data as argument.

## `onReject`

> `function(reason: Error): void`

Callback function invoked when a promise rejects, receives rejection reason (error) as argument.

## `onCancel`

> `function(): void`

Callback function invoked when a promise is cancelled, either manually using `cancel()` or automatically due to arguments changes or unrendering.