## Autocomplete Widget version added: 1.8

Description: Autocomplete enables users to quickly find and select from a pre-populated list of values as they type, leveraging searching and filtering.

## Options

### appendToType: Selector

Default: `"body"`
Which element the menu should be appended to. Override this when the autocomplete is inside a `position: fixed` element. Otherwise the popup menu would still scroll with the page.
Code examples:

Initialize the autocomplete with the appendTo option specified:

`$(` `".selector"` `).autocomplete({ appendTo:` `"#someElem"` `});`

Get or set the appendTo option, after initialization:

`// getter` `var` `appendTo = $(` `".selector"` `).autocomplete(` `"option"``,` `"appendTo"` `);` `// setter` `$(` `".selector"` `).autocomplete(` `"option"``,` `"appendTo"``,` `"#someElem"` `);`

### autoFocusType: Boolean

Default: `false`
If set to `true` the first item will automatically be focused when the menu is shown.
Code examples:

Initialize the autocomplete with the autoFocus option specified:

`$(` `".selector"` `).autocomplete({ autoFocus:` `true` `});`

Get or set the autoFocus option, after initialization:

`// getter` `var` `autoFocus = $(` `".selector"` `).autocomplete(` `"option"``,` `"autoFocus"` `);` `// setter` `$(` `".selector"` `).autocomplete(` `"option"``,` `"autoFocus"``,` `true` `);`

### delayType: Integer

Default: `300`
The delay in milliseconds between when a keystroke occurs and when a search is performed. A zero-delay makes sense for local data (more responsive), but can produce a lot of load for remote data, while being less responsive.
Code examples:

Initialize the autocomplete with the delay option specified:

`$(` `".selector"` `).autocomplete({ delay: 500 });`

Get or set the delay option, after initialization:

`// getter` `var` `delay = $(` `".selector"` `).autocomplete(` `"option"``,` `"delay"` `);` `// setter` `$(` `".selector"` `).autocomplete(` `"option"``,` `"delay"``, 500 );`

### disabledType: Boolean

Default: `false`
Disables the autocomplete if set to `true`.
Code examples:

Initialize the autocomplete with the disabled option specified:

`$(` `".selector"` `).autocomplete({ disabled:` `true` `});`

Get or set the disabled option, after initialization:

`// getter` `var` `disabled = $(` `".selector"` `).autocomplete(` `"option"``,` `"disabled"` `);` `// setter` `$(` `".selector"` `).autocomplete(` `"option"``,` `"disabled"``,` `true` `);`

### minLengthType: Integer

Default: `1`
The minimum number of characters a user must type before a search is performed. Zero is useful for local data with just a few items, but a higher value should be used when a single character search could match a few thousand items.
Code examples:

Initialize the autocomplete with the minLength option specified:

`$(` `".selector"` `).autocomplete({ minLength: 0 });`

Get or set the minLength option, after initialization:

`// getter` `var` `minLength = $(` `".selector"` `).autocomplete(` `"option"``,` `"minLength"` `);` `// setter` `$(` `".selector"` `).autocomplete(` `"option"``,` `"minLength"``, 0 );`

### positionType: Object

Default: `{ my: "left top", at: "left bottom", collision: "none" }`
Identifies the position of the suggestions menu in relation to the associated input element. The `of` option defaults to the input element, but you can specify another element to position against. You can refer to the jQuery UI Position utility for more details about the various options.
Code examples:

Initialize the autocomplete with the position option specified:

`$(` `".selector"` `).autocomplete({ position: { my :` `"right top"``, at:` `"right bottom"` `} });`

Get or set the position option, after initialization:

`// getter` `var` `position = $(` `".selector"` `).autocomplete(` `"option"``,` `"position"` `);` `// setter` `$(` `".selector"` `).autocomplete(` `"option"``,` `"position"``, { my :` `"right top"``, at:` `"right bottom"` `} );`

### sourceType: Array or String or Function( Object request, Function response( Object data ) )

Default: `none; must be specified`
Defines the data to use, must be specified.

Independent of the variant you use, the label is always treated as text. If you want the label to be treated as html you can use Scott González' html extension. The demos all focus on different variations of the `source` option - look for one that matches your use case, and check out the code.

Multiple types supported:

- Array: An array can be used for local data. There are two supported formats:
  - An array of strings: `[ "Choice1", "Choice2" ]`
  - An array of objects with `label` and `value` properties: `[ { label: "Choice1", value: "value1" }, ... ]`
  The label property is displayed in the suggestion menu. The value will be inserted into the input element when a user selects an item. If just one property is specified, it will be used for both, e.g., if you provide only `value` properties, the value will also be used as the label.
- String: When a string is used, the Autocomplete plugin expects that string to point to a URL resource that will return JSON data. It can be on the same host or on a different one (must provide JSONP). The Autocomplete plugin does not filter the results, instead a query string is added with a `term` field, which the server-side script should use for filtering the results. For example, if the `source` option is set to `"http://example.com"` and the user types `foo`, a GET request would be made to `http://example.com?term=foo`. The data itself can be in the same format as the local data described above.
- Function: The third variation, a callback, provides the most flexibility and can be used to connect any data source to Autocomplete. The callback gets two arguments:
  - A `request` object, with a single `term` property, which refers to the value currently in the text input. For example, if the user enters `"new yo"` in a city field, the Autocomplete term will equal `"new yo"`.
  - A `response` callback, which expects a single argument: the data to suggest to the user. This data should be filtered based on the provided term, and can be in any of the formats described above for simple local data. It's important when providing a custom source callback to handle errors during the request. You must always call the `response` callback even if you encounter an error. This ensures that the widget always has the correct state.

  When filtering data locally, you can make use of the built-in `$.ui.autocomplete.escapeRegex` function. It'll take a single string argument and escape all regex characters, making the result safe to pass to `new RegExp()`.

Code examples:

Initialize the autocomplete with the source option specified:

`$(` `".selector"` `).autocomplete({ source: [` `"c++"``,` `"java"``,` `"php"``,` `"coldfusion"``,` `"javascript"``,` `"asp"``,` `"ruby"` `] });`

Get or set the source option, after initialization:

`// getter` `var` `source = $(` `".selector"` `).autocomplete(` `"option"``,` `"source"` `);` `// setter` `$(` `".selector"` `).autocomplete(` `"option"``,` `"source"``, [` `"c++"``,` `"java"``,` `"php"``,` `"coldfusion"``,` `"javascript"``,` `"asp"``,` `"ruby"` `] );`

## Methods

### close()

Closes the Autocomplete menu. Useful in combination with the `search` method, to close the open menu.

- This method does not accept any arguments.

### destroy()

Removes the autocomplete functionality completely. This will return the element back to its pre-init state.

- This method does not accept any arguments.

### disable()

Disables the autocomplete.

- This method does not accept any arguments.

### enable()

Enables the autocomplete.

- This method does not accept any arguments.

### option( optionName ) Returns: Object

Gets the value currently associated with the specified `optionName`.

- optionName
  Type: String
  The name of the option to get.

### option() Returns: PlainObject

Gets an object containing key/value pairs representing the current autocomplete options hash.

- This method does not accept any arguments.

### option( optionName, value )

Sets the value of the autocomplete option associated with the specified `optionName`.

- optionName
  Type: String
  The name of the option to set.
- value
  Type: Object
  A value to set for the option.

### option( options )

Sets one or more options for the autocomplete.

- options
  Type: Object
  A map of option-value pairs to set.

### search( [value ] )

Triggers a `search` event and invokes the data source if the event is not canceled. Can be used by a selectbox-like button to open the suggestions when clicked. When invoked with no parameters, the current input's value is used. Can be called with an empty string and `minLength: 0` to display all items.

- value
  Type: String

### widget()

Returns a `jQuery` object containing the menu element. Although the menu items are constantly created and destroyed, the menu element itself is created during initialization and is constantly reused.

- This method does not accept any arguments.

## Events

### change( event, ui )

Triggered when the field is blurred, if the value has changed.

- event
  Type: Event
- ui
  Type: Object
  - item
    Type: jQuery
    The item selected from the menu, if any. Otherwise the property is `null`.

### close( event, ui )

Triggered when the menu is hidden. Not every `close` event will be accompanied by a `change` event.

- event
  Type: Event
- ui
  Type: Object

### create( event, ui )

Triggered when the autocomplete is created.

- event
  Type: Event
- ui
  Type: Object

### focus( event, ui )

Triggered when focus is moved to an item (not selecting). The default action is to replace the text field's value with the value of the focused item, though only if the event was triggered by a keyboard interaction.

Canceling this event prevents the value from being updated, but does not prevent the menu item from being focused.

- event
  Type: Event
- ui
  Type: Object
  - item
    Type: jQuery
    The focused item.

### open( event, ui )

Triggered when the suggestion menu is opened or updated.

- event
  Type: Event
- ui
  Type: Object

### response( event, ui )

Triggered after a search completes, before the menu is shown. Useful for local manipulation of suggestion data, where a custom `source` option callback is not required. This event is always triggered when a search completes, even if the menu will not be shown because there are no results or the Autocomplete is disabled.

- event
  Type: Event
- ui
  Type: Object
  - content
    Type: Array
    Contains the response data and can be modified to change the results that will be shown. This data is already normalized, so if you modify the data, make sure to include both `value` and `label` properties for each item.

### search( event, ui )

Triggered before a search is performed, after `minLength` and `delay` are met. If canceled, then no request will be started and no items suggested.

- event
  Type: Event
- ui
  Type: Object

### select( event, ui )

Triggered when an item is selected from the menu. The default action is to replace the text field's value with the value of the selected item.

Canceling this event prevents the value from being updated, but does not prevent the menu from closing.

- event
  Type: Event
- ui
  Type: Object
  - item
    Type: jQuery
    The selected item.

By giving an Autocomplete field focus or entering something into it, the plugin starts searching for entries that match and displays a list of values to choose from. By entering more characters, the user can filter down the list to better matches.

This can be used to choose previously selected values, such as entering tags for articles or entering email addresses from an address book. Autocomplete can also be used to populate associated information, such as entering a city name and getting the zip code.

You can pull data in from a local or remote source: Local is good for small data sets, e.g., an address book with 50 entries; remote is necessary for big data sets, such as a database with hundreds or millions of entries to select from. To find out more about customizing the data soure, see the documentation for the `source` option.

### Keyboard interaction

When the menu is open, the following key commands are available:

- UP - Move focus to the previous item. If on first item, move focus to the input. If on the input, move focus to last item.
- DOWN - Move focus to the next item. If on last item, move focus to the input. If on the input, move focus to the first item.
- ESCAPE - Close the menu.
- ENTER - Select the currently focused item and close the menu.
- TAB - Select the currently focused item, close the menu, and move focus to the next focusable element.
- PAGE UP/DOWN - Scroll through a page of items (based on height of menu). It's generally a bad idea to display so many items that users need to page..

When the menu is closed, the following key commands are available:

- UP/DOWN - Open the menu, if the `minLength` has been met.

### Additional Notes:

- This widget requires some functional CSS, otherwise it won't work. If you build a custom theme, use the widget's specific CSS file as a starting point.

## Examples:

#### Example: A simple jQuery UI Autocomplete

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 | `<!doctype html>` `<``html` `lang``=``"en"``>` `<``head``>` `` `<``meta` `charset``=``"utf-8"``>` `` `<``title``>autocomplete demo</``title``>` `` `<``link` `rel``=``"stylesheet"` `href``=``"http://code.jquery.com/ui/1.9.1/themes/base/jquery-ui.css"``>` `` `<``script` `src``=``"http://code.jquery.com/jquery-1.8.2.js"``></``script``>` `` `<``script` `src``=``"http://code.jquery.com/ui/1.9.1/jquery-ui.js"``></``script``>` `</``head``>` `<``body``>` `<``label` `for``=``"autocomplete"``>Select a programming language: </``label``>` `<``input` `id``=``"autocomplete"``>` `<``script``>` `$( "#autocomplete" ).autocomplete({` `` `source: [ "c++", "java", "php", "coldfusion", "javascript", "asp", "ruby" ]` `});` `</``script``>` `</``body``>` `</``html``>`

#### Demo:

#### Example: Using a custom source callback to match only the beginning of terms

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 | `<!doctype html>` `<``html` `lang``=``"en"``>` `<``head``>` `` `<``meta` `charset``=``"utf-8"``>` `` `<``title``>autocomplete demo</``title``>` `` `<``link` `rel``=``"stylesheet"` `href``=``"http://code.jquery.com/ui/1.9.1/themes/base/jquery-ui.css"``>` `` `<``script` `src``=``"http://code.jquery.com/jquery-1.8.2.js"``></``script``>` `` `<``script` `src``=``"http://code.jquery.com/ui/1.9.1/jquery-ui.js"``></``script``>` `</``head``>` `<``body``>` `<``label` `for``=``"autocomplete"``>Select a programming language: </``label``>` `<``input` `id``=``"autocomplete"``>` `<``script``>` `var tags = [ "c++", "java", "php", "coldfusion", "javascript", "asp", "ruby" ];` `$( "#autocomplete" ).autocomplete({` `` `source: function( request, response ) {` `` `var matcher = new RegExp( "^" + $.ui.autocomplete.escapeRegex( request.term ), "i" );` `` `response( $.grep( tags, function( item ){` `` `return matcher.test( item );` `` `}) );` `` `}` `});` `</``script``>` `</``body``>` `</``html``>`

#### Demo: