constructor

new AsyncChoices

options

AsyncChoices

AsyncChoicesInterface.multiple

multiple

boolean

AsyncChoicesOptions

ItemType

ValueType

AsyncChoicesInterface.getChoices

getChoices

items

AsyncChoicesInterface.getLabel

getLabel

item

React.ReactNode

AsyncChoicesInterface.getMissingLabel

getMissingLabel

value

AsyncChoicesInterface.getValue

getValue

AsyncChoicesInterface.list

list

params

Promise

AsyncChoicesInterface.retrieve

retrieve

deps

AsyncChoicesInterface.useListProps

useListProps

args

AsyncChoicesInterface.useResolveItems

useResolveItems

AsyncChoicesInterface.useRetrieveProps

useRetrieveProps

Default implementation for [AsyncChoicesInterface](doc:AsyncChoicesInterface)

All options can be customised via `options`.

You must provide `list` and `retrieve` - everything else can be optional with the following restrictions:

* `getLabel` - this is optional if items returned by `list` and `retrieve` implement [NodeLabeled](doc:NodeLabeled) otherwise it must be provided
* `getValue` - this is optional if items returned by `list` and `retrieve` implement [Identifiable](doc:Identifiable) otherwise it must be provided


Constructors

Properties

Methods

AsyncChoicesInterface

TestDataItem

number

label

string

Variables

__type

new Record

Record

__get

_key

Accessors

__index

Choice

If true then multiple values can be selected. When this is true
retrieve() will be passed and return an array rather than a single value.

Generate the list of choices. This can return an array of single choices or grouped choices.

A grouped choice is a 2 element Array with a label and a list of choices.


Return label to use when an item can't be found. This can be used by widgets to control
what is rendered when an item for a value cannot be found (eg. when it's deleted or
when it's loading). The exact details of how this is used depend on the widget.

Get the value to use for an item. The value should be unique and is what's used when a
choice is selected (eg. it's the value that would be saved to a database).

Function to resolve a list of choices based on the provided params.

What this function is passed depends on the implementation but when used with
[useAsyncChoices](doc:useAsyncChoices) it will be passed `query` (the query object eg. to
filter results with), `paginator` (the current paginator if any) and `listOptions` (any
additional options passed on the `listOptions` prop to `useAsyncChoices`).
Official presto widgets all use `useAsyncChoices` and so will use these parameters.


Function to resolve specific values. This is used to know how to render the label for a value(s).

The first parameter is the value to retrieve (will be an array when `multiple` is true).

`deps` is the value returned by `useRetrieveProps`.


Hook that returns any extra props to pass through to `list` in components/hooks that
consume this (eg. [useAsyncChoices](doc:useAsyncChoices)). This is useful to
store state for things like pagination.

What this function is passed depends on the implementation but when used with
[useAsyncChoices](doc:useAsyncChoices) it will be `query` (the query object eg. to
filter results with) and `listOptions` (any additional options passed on the `listOptions`
prop to `useAsyncChoices`).
Official presto widgets all use `useAsyncChoices` and so will use these parameters.


Resolve the specific instance of an item to use. By default this should just return `item`
but can be used to resolve a specific instance of a class from a cache for example.

Hook that returns props to pass through to `retrieve` in components/hooks that consume this (eg. [useAsyncChoices](doc:useAsyncChoices).
This is useful for things like hooking into an existing cache (eg. [useViewModelCache](doc:useViewModelCache)).
The value returned here is passed as the second parameter to `retrieve`. In addition the `existingValues` key is
passed through to `useAsyncValue` as the list of items it can resolve existing values from.

What this function is passed depends on the implementation but when used with
[useAsyncChoices](doc:useAsyncChoices) it will be passed `id` if there's a current value
and it's not an array, `ids` if there's a current value and it is an array, `existingValues` which is
the values returned by `list` (may be null if `list` not yet called) and `retrieveOptions`
(any additional options passed on the `retrieveOptions` prop to `useAsyncChoices`).
Official presto widgets all use `useAsyncChoices` and so will use these parameters.


A choice is a `value` that identifies the item (eg. an id) and a `label` that
describes the item and is shown to users (eg. the name).

When `multiple` is true multiple values can be selected.

To define async choices two things are required:

1) A function to resolve existing value(s). This is used when viewing existing
   value(s) and need label(s) to show (eg. when displaying a choice on a detail
   view or rendering the value selected on a select widget).
2) A function to list & filter the available  choices. This is used when selecting
   a value (eg. the options shown in a select widget).

Both of these functions may need to store state (eg. pagination for a listing)
or access things from context (eg. read values from a cache). This can be done
via two hooks - `useListProps` and `useRetrieveProps`. This functions should be
called from a component or hook that deals with async choices when calling
`list` and `retrieve` respectively. The return value from the hook is passed to
the corresponding function.

For a default implementation see [AsyncChoices](doc:AsyncChoices)


AsyncChoices

API

Constructor

new AsyncChoices(options)

Methods

getChoices(items)

getLabel(item)

getMissingLabel(value)

getValue(item)

list(params)

retrieve(value,?deps)

useListProps(args)

useResolveItems(items)

useRetrieveProps(args)

Properties

multiple: boolean

options:
AsyncChoicesOptions

	Parameter	Type	Description
*	value	ValueType[]\|ValueType
	deps	any

API

Constructor

new AsyncChoices(options)

Methods

getChoices(items)

getLabel(item)

getMissingLabel(value)

getValue(item)

list(params)

retrieve(value,?deps)

useListProps(args)

useResolveItems(items)

useRetrieveProps(args)

Properties

multiple: boolean

options: AsyncChoicesOptions

options:
AsyncChoicesOptions