# Class yii\bootstrap\Collapse

Inheritance | yii\bootstrap\Collapse » yii\bootstrap\Widget » yii\base\Widget » yii\base\Component » yii\base\BaseObject
Implements | yii\base\Configurable, yii\base\ViewContextInterface
Uses Traits | yii\bootstrap\BootstrapWidgetTrait
Available since version | 2.0
Source Code | https://github.com/yiisoft/yii2-bootstrap/blob/master/Collapse.php

Collapse renders an accordion bootstrap javascript component.

For example:

    echo Collapse::widget([
        'items' => [
            // equivalent to the above
            [
                'label' => 'Collapsible Group Item #1',
                'content' => 'Anim pariatur cliche...',
                // open its content by default
                'contentOptions' => ['class' => 'in']
            ],
            // another group item
            [
                'label' => 'Collapsible Group Item #1',
                'content' => 'Anim pariatur cliche...',
                'contentOptions' => [...],
                'options' => [...],
            ],
            // if you want to swap out .panel-body with .list-group, you may use the following
            [
                'label' => 'Collapsible Group Item #1',
                'content' => [
                    'Anim pariatur cliche...',
                    'Anim pariatur cliche...'
                ],
                'contentOptions' => [...],
                'options' => [...],
                'footer' => 'Footer' // the footer label in list-group
            ],
        ]
    ]);

See also http://getbootstrap.com/javascript/#collapse.

## Public Properties

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Property | Type | Description | Defined By
--- | --- | --- | ---
$autoCloseItems | boolean | Whether to close other items if an item is opened. | yii\bootstrap\Collapse
$autoIdPrefix | string | The prefix to the automatically generated widget IDs. | yii\base\Widget
$behaviors | yii\base\Behavior[] | List of behaviors attached to this component. This property is read-only. | yii\base\Component
$clientEvents | array | The event handlers for the underlying Bootstrap JS plugin. | yii\bootstrap\BootstrapWidgetTrait
$clientOptions | array | The options for the underlying Bootstrap JS plugin. | yii\bootstrap\BootstrapWidgetTrait
$counter | integer | A counter used to generate $id for widgets. | yii\base\Widget
$encodeLabels | boolean | Whether the labels for header items should be HTML-encoded. | yii\bootstrap\Collapse
$id | string|null | ID of the widget. Note that the type of this property differs in getter and setter. See getId() and setId() for details. | yii\base\Widget
$itemToggleOptions | array | The HTML options for the item toggle tag. | yii\bootstrap\Collapse
$items | array | List of groups in the collapse widget. | yii\bootstrap\Collapse
$options | array | The HTML attributes for the widget container tag. | yii\bootstrap\Widget
$stack | yii\base\Widget[] | The widgets that are currently being rendered (not ended). | yii\base\Widget
$view | yii\web\View | The view object that can be used to render views or view files. Note that the type of this property differs in getter and setter. See getView() and setView() for details. | yii\base\Widget
$viewPath | string | The directory containing the view files for this widget. This property is read-only. | yii\base\Widget

## Public Methods

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Method | Description | Defined By
--- | --- | ---
__call() | Calls the named method which is not a class method. | yii\base\Component
__clone() | This method is called after the object is created by cloning an existing one. | yii\base\Component
__construct() | Constructor. | yii\base\BaseObject
__get() | Returns the value of a component property. | yii\base\Component
__isset() | Checks if a property is set, i.e. defined and not null. | yii\base\Component
__set() | Sets the value of a component property. | yii\base\Component
__unset() | Sets a component property to be null. | yii\base\Component
afterRun() | This method is invoked right after a widget is executed. | yii\base\Widget
attachBehavior() | Attaches a behavior to this component. | yii\base\Component
attachBehaviors() | Attaches a list of behaviors to the component. | yii\base\Component
beforeRun() | This method is invoked right before the widget is executed. | yii\base\Widget
begin() | Begins a widget. | yii\base\Widget
behaviors() | Returns a list of behaviors that this component should behave as. | yii\base\Component
canGetProperty() | Returns a value indicating whether a property can be read. | yii\base\Component
canSetProperty() | Returns a value indicating whether a property can be set. | yii\base\Component
className() | Returns the fully qualified name of this class. | yii\base\BaseObject
detachBehavior() | Detaches a behavior from the component. | yii\base\Component
detachBehaviors() | Detaches all behaviors from the component. | yii\base\Component
end() | Ends a widget. | yii\base\Widget
ensureBehaviors() | Makes sure that the behaviors declared in behaviors() are attached to this component. | yii\base\Component
getBehavior() | Returns the named behavior object. | yii\base\Component
getBehaviors() | Returns all behaviors attached to this component. | yii\base\Component
getId() | Returns the ID of the widget. | yii\base\Widget
getView() |  | yii\bootstrap\BootstrapWidgetTrait
getViewPath() | Returns the directory containing the view files for this widget. | yii\base\Widget
hasEventHandlers() | Returns a value indicating whether there is any handler attached to the named event. | yii\base\Component
hasMethod() | Returns a value indicating whether a method is defined. | yii\base\Component
hasProperty() | Returns a value indicating whether a property is defined for this component. | yii\base\Component
init() | Initializes the widget. | yii\bootstrap\Collapse
off() | Detaches an existing event handler from this component. | yii\base\Component
on() | Attaches an event handler to an event. | yii\base\Component
render() | Renders a view. | yii\base\Widget
renderFile() | Renders a view file. | yii\base\Widget
renderItem() | Renders a single collapsible item group | yii\bootstrap\Collapse
renderItems() | Renders collapsible items as specified on $items. | yii\bootstrap\Collapse
run() | Renders the widget. | yii\bootstrap\Collapse
setId() | Sets the ID of the widget. | yii\base\Widget
setView() | Sets the view object to be used by this widget. | yii\base\Widget
trigger() | Triggers an event. | yii\base\Component
widget() | Creates a widget instance and runs it. | yii\base\Widget

## Protected Methods

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Method | Description | Defined By
--- | --- | ---
registerClientEvents() | Registers JS event handlers that are listed in $clientEvents. | yii\bootstrap\BootstrapWidgetTrait
registerPlugin() | Registers a specific Bootstrap plugin and the related events | yii\bootstrap\BootstrapWidgetTrait

## Events

Hide inherited events

Event | Type | Description | Defined By
--- | --- | --- | ---
EVENT_AFTER_RUN | yii\base\WidgetEvent | An event raised right after executing a widget. (available since version 2.0.11) | yii\base\Widget
EVENT_BEFORE_RUN | yii\base\WidgetEvent | An event raised right before executing a widget. (available since version 2.0.11) | yii\base\Widget
EVENT_INIT | yii\base\Event | An event that is triggered when the widget is initialized via init(). (available since version 2.0.11) | yii\base\Widget

## Property Details

$autoCloseItems public property (available since version 2.0.7)

Whether to close other items if an item is opened. Defaults to `true` which causes an accordion effect. Set this to `false` to allow keeping multiple items open at once.

public boolean $autoCloseItems = true
$encodeLabels public property

Whether the labels for header items should be HTML-encoded.

public boolean $encodeLabels = true
$itemToggleOptions public property (available since version 2.0.8)

The HTML options for the item toggle tag. Key 'tag' might be used here for the tag name specification. For example:

    [
        'tag' => 'div',
        'class' => 'custom-toggle',
    ]

public array $itemToggleOptions = []
$items public property

List of groups in the collapse widget. Each array element represents a single group with the following structure:

- label: string, required, the group header label.
- encode: bool, optional, whether this label should be HTML-encoded. This param will override global `$this->encodeLabels` param.
- content: array|string|object, required, the content (HTML) of the group
- options: array, optional, the HTML attributes of the group
- contentOptions: optional, the HTML attributes of the group's content

Since version 2.0.7 you may also specify this property as key-value pairs, where the key refers to the `label` and the value refers to `content`. If value is a string it is interpreted as label. If it is an array, it is interpreted as explained above.

For example:

    echo Collapse::widget([
        'items' => [
          'Introduction' => 'This is the first collapsable menu',
          'Second panel' => [
              'content' => 'This is the second collapsable menu',
          ],
          [
              'label' => 'Third panel',
              'content' => 'This is the third collapsable menu',
          ],
      ]
    ])

public array $items = []

## Method Details

init() public method

Initializes the widget.

public void init ( )

renderItem() public method

Renders a single collapsible item group

public string renderItem ( $header, $item, $index )
$header | string | A label of the item group $items
$item | array | A single item from $items
$index | integer | The item index as each item group content must have an id
return | string | The rendering result
throws | yii\base\InvalidConfigException |

renderItems() public method

Renders collapsible items as specified on $items.

public string renderItems ( )
return | string | The rendering result
throws | yii\base\InvalidConfigException | if label isn't specified

run() public method

Renders the widget.

public void run ( )