# QueryControls

## Development Guidelines

### Usage

```jsx
import { QueryControls } from '@wordpress/components';
import { useState } from '@wordpress/element';

const QUERY_DEFAULTS = {
	category: 1,
	categories: [
		{
			id: 1,
			name: 'Category 1',
			parent: 0,
		},
		{
			id: 2,
			name: 'Category 1b',
			parent: 1,
		},
		{
			id: 3,
			name: 'Category 2',
			parent: 0,
		},
	],
	maxItems: 20,
	minItems: 1,
	numberOfItems: 10,
	order: 'asc',
	orderBy: 'title',
};

const MyQueryControls = () => {
	const [ query, setQuery ] = useState( QUERY_DEFAULTS );
	const { category, categories, maxItems, minItems, numberOfItems, order, orderBy  } = query;

	const updateQuery = ( newQuery ) => {
		setQuery( { ...query, ...newQuery } );
	};

	return (
		<QueryControls
			{ ...{ maxItems, minItems, numberOfItems, order, orderBy } }
			onOrderByChange={ ( newOrderBy ) => updateQuery( { orderBy: newOrderBy } ) }
			onOrderChange={ ( newOrder ) => updateQuery( { order: newOrder } ) }
			categoriesList={ categories }
			selectedCategoryId={ category }
			onCategoryChange={ ( newCategory ) => updateQuery( { category: newCategory } ) }
			onNumberOfItemsChange={ ( newNumberOfItems ) =>
				updateQuery( { numberOfItems: newNumberOfItems } )
			}
		/>
	);
};
```

### Multiple category selector

The `QueryControls` component now supports multiple category selection, to replace the single category selection available so far. To enable it use the component with the new props instead: `categorySuggestions` in place of `categoriesList` and the `selectedCategories` array instead of `selectedCategoryId` like so:

```jsx
const QUERY_DEFAULTS = {
	orderBy: 'title',
	order: 'asc',
	selectedCategories: [
		{
			id: 1,
			value: 'Category 1',
			parent: 0,
		},
		{
			id: 2,
			value: 'Category 1b',
			parent: 1,
		},
	],
	categories: {
		'Category 1': {
			id: 1,
			name: 'Category 1',
			parent: 0,
		},
		'Category 1b': {
			id: 2,
			name: 'Category 1b',
			parent: 1,
		},
		'Category 2': {
			id: 3,
			name: 'Category 2',
			parent: 0,
		},
	},
	numberOfItems: 10,
};

const MyQueryControls = () => {
	const [ query, setQuery ] = useState( QUERY_DEFAULTS );
	const { orderBy, order, selectedCategories, categories, numberOfItems } = query;

	const updateQuery = ( newQuery ) => {
		setQuery( { ...query, ...newQuery } );
	};

	return (
		<QueryControls
			{ ...{ orderBy, order, numberOfItems } }
			onOrderByChange={ ( newOrderBy ) => updateQuery( { orderBy: newOrderBy } ) }
			onOrderChange={ ( newOrder ) => updateQuery( { order: newOrder } ) }
			categorySuggestions={ categories }
			selectedCategories={ selectedCategories }
			onCategoryChange={ ( category ) => updateQuery( { selectedCategories: category } ) }
			onNumberOfItemsChange={ ( newNumberOfItems ) =>
				updateQuery( { numberOfItems: newNumberOfItems } )
			}
		/>
	);
};
```

The format of the categories list also needs to be updated to match the expected type for the category suggestions.

### Props

#### `authorList`: `Author[]`

An array of the authors to select from.

-   Required: No
-   Platform: Web

#### `categoriesList`: `Category[]`

An array of categories. When passed in conjunction with the `onCategoryChange` prop, it causes the component to render UI that allows selecting one category at a time.

-   Required: No
-   Platform: Web

#### `categorySuggestions`: `Record< Category[ 'name' ], Category >`

An object of categories with the category name as the key. When passed in conjunction with the `onCategoryChange` prop, it causes the component to render UI that enables multiple selection.

-   Required: No
-   Platform: Web

#### `maxItems`: `number`

The maximum number of items.

-   Required: No
-   Default: 100
-   Platform: Web

#### `minItems`: `number`

The minimum number of items.

-   Required: No
-   Default: 1
-   Platform: Web

#### `numberOfItems`: `number`

The selected number of items to retrieve via the query.

-   Required: No
-   Platform: Web

#### `onAuthorChange`: `( newAuthor: string ) => void`

A function that receives the new author value. If not specified, the author controls are not rendered.

-   Required: No
-   Platform: Web

#### `onCategoryChange`: `( newCategory: string ) => void | FormTokenFieldProps[ 'onChange' ]`

A function that receives the new category value. If not specified, the category controls are not rendered.
The function's signature changes depending on whether multiple category selection is enabled or not.

-   Required: No
-   Platform: Web

#### `onNumberOfItemsChange`: `( newNumber?: number ) => void`

A function that receives the new number of items. If not specified, then the number of items range control is not rendered.

-   Required: No
-   Platform: Web

#### `onOrderChange`: `( newOrder: 'asc' | 'desc' ) => void`

A function that receives the new order value. If this prop or the `onOrderByChange` prop are not specified, then the order controls are not rendered.

-   Required: No
-   Platform: Web

#### `onOrderByChange`: `( newOrderBy: 'date' | 'title' ) => void`

A function that receives the new orderby value. If this prop or the `onOrderChange` prop are not specified, then the order controls are not rendered.

-   Required: No
-   Platform: Web

#### `order`: `'asc' | 'desc'`

The order in which to retrieve posts.

-   Required: No
-   Platform: Web

#### `orderBy`: `'date' | 'title'`

The meta key by which to order posts.

-   Required: No
-   Platform: Web

#### `selectedAuthorId`: `number`

The selected author ID.

-   Required: No
-   Platform: Web

#### `selectedCategories`: `Category[]`

The selected categories for the `categorySuggestions` prop.

-   Required: No
-   Platform: Web

#### `selectedCategoryId`: `number`

The selected category for the `categoriesList` prop.

-   Required: No
-   Platform: Web