PlainDropdownList

Given a string value for a named boolean attribute, return true if the value is either: a) the empty string, or b) a case-insensitive match for the name.

This is native HTML behavior; see the MDN documentation on boolean attributes for the reasoning.

Given a null value, this return false. Given a boolean value, this return the value as is.

Parameters:

• name: string –
• value: string|boolean|null –

Defined by AttributeMarshallingMixin

Close the component (if not already closed).

Some components like AlertDialog want to indicate why or how they were closed. To support such scenarios, you can supply a value to the optional closeResult parameter. This closeResult will be made available in the whenClosed promise and the state.closeResult member.

Parameters:

• closeResult: object – an indication of how or why the element closed

Defined by OpenCloseMixin

Raised when the component closes.

Defined by OpenCloseMixin

True if the element is currently closed.

This read-only property is provided as a convenient inverse of opened.

Type: boolean

Defined by OpenCloseMixin

True if the element has completely closed.

For components not using asynchronous open/close effects, this property returns the same value as the closed property. For elements that have a true value of state.openCloseEffects (e.g., elements using TransitionEffectMixin), this property returns true only if state.effect is "close" and state.effectPhase is "after".

Type: boolean

Defined by OpenCloseMixin

Look for an item which is available in the given state..

The options parameter can accept options for:

• direction: 1 to move forward, -1 to move backward
• index: the index to start at, defaults to state.currentIndex
• wrap: whether to wrap around the ends of the items array, defaults to state.cursorOperationsWrap.

If an available item was found, this returns its index. If no item was found, this returns -1.

Parameters:

• state: PlainObject –
• options: PlainObject –

Returns: number

Defined by ItemsCursorMixin

See contentSlot.

Defined by SlotContentMixin

The index of the current item, or -1 if no item is current.

Type: number

Defined by CursorAPIMixin

Raised when the currentIndex property changes.

Defined by CursorAPIMixin

The current item, or null if no item is current.

Type: Element

Defined by CursorAPIMixin

True if the list should always have a current item (if it has items).

Type: boolean

Default: false

Defined by CursorAPIMixin

True if cursor operations wrap from last to first, and vice versa.

Type: boolean

Default: false

Defined by CursorAPIMixin

The default state for the component. This can be extended by mixins and classes to provide additional default state.

Type: PlainObject

Defined by ReactiveMixin

Returns true if the component is delegating its focus.

A component using DelegateFocusMixin will always have this property be true unless a class takes measures to override it.

Type: boolean

Default: true

Defined by DelegateFocusMixin

True if the component is disabled, false (the default) if not.

The value of this property will be reflected to the disabled attribute so that it can be referenced in CSS. Note that this non-native implementation of the disabled attribute will not trigger the :disabled CSS pseudo-class, so your style rules will have to reference the presence or absence of the disabled attribute. That is, instead of writing

my-component:disabled { ... }

write this instead

my-component[disabled] { ... }

Like the native disabled attribute, this attribute is boolean. That means that it's existence in markup sets the attribute, even if set to an empty string or a string like "false".

Type: boolean

Default: false

Defined by DisabledMixin

Raised when the disabled property changes.

Defined by DisabledMixin

The ID of the form element with which this element is associated, or null if the element is not associated with any form. This is provided for consistency with the native HTML form property.

Type: string

Defined by FormElementMixin

Extract the text from the given item.

The default implementation returns an item's aria-label, alt attribute, innerText, or textContent, in that order. You can override this to return the text that should be used.

Parameters:

• item: Element –

Returns: string

Defined by SelectedTextAPIMixin

Moves to the first item in the list.

Returns: Boolean True if the current item changed, false if not.

Defined by CursorAPIMixin

Move to the last item in the list.

Returns: Boolean True if the current item changed

Defined by CursorAPIMixin

Move to the next item in the list.

If the list has no current item, the first item will become current.

Returns: Boolean True if the current item changed

Defined by CursorAPIMixin

Moves to the previous item in the list.

If the list has no current item, the last item will become current.

Returns: Boolean True if the current item changed

Defined by CursorAPIMixin

A convenient shortcut for looking up an element by ID in the component's Shadow DOM subtree.

Example: if component's template contains a shadow element <button id="foo">, you can use the reference this[ids].foo to obtain the corresponding button in the component instance's shadow tree. The ids property is simply a shorthand for getElementById, so this[ids].foo is the same as this[shadowRoot].getElementById('foo').

Type: object

Defined by ShadowTemplateMixin

Move to the first item in the set.

Returns: Boolean True if the current item changed, false if not.

Defined by ItemsCursorMixin

Move to the last item in the set.

Returns: Boolean True if the current item changed, false if not.

Defined by ItemsCursorMixin

Move to the next item in the set.

If no item is current, move to the first item.

Returns: Boolean True if the current item changed, false if not.

Defined by ItemsCursorMixin

Move to the previous item in the set.

If no item is current, move to the last item.

Returns: Boolean True if the current item changed, false if not.

Defined by ItemsCursorMixin

The current set of items drawn from the element's current state.

Type: Array.

Defined by ItemsAPIMixin

Raised when the items property changes.

Defined by ItemsAPIMixin

See the symbols documentation for details.

Defined by KeyboardMixin

The class or tag used to define the list part – the element presenting the list items and handling navigation between them.

Type: (component class constructor)|HTMLTemplateElement|string

Default: List

Defined by DropdownList

The name of the form field that will be filled with this element's value. This is an analogue of the standard HTML name property.

Type: string

Defined by FormElementMixin

Open the element (if not already opened).

Defined by OpenCloseMixin

Raised when the component opens.

Defined by OpenCloseMixin

True if the element is currently opened.

This property can be set as a boolean attribute

Type: boolean

Default: false

Defined by OpenCloseMixin

Raised when the opened/closed state of the component changes.

Defined by OpenCloseMixin

The alignment of the popup with respect to the source button.

• bottom: popup and source are bottom-aligned
• end: popup and source are aligned on the trailing edge according to the text direction
• left: popup and source are left-aligned
• right: popup and source are right-aligned
• start: popup and source are aligned on the leading edge according to the text direction
• stretch: both left and right edges are aligned
• top: popup and source are top-aligned

   <p><span class="apiLabel">Type:</span> <code>'bottom'|'end'|'left'|'right'|'start'|'stretch'|'top'</code></p> <p><span class="apiLabel">Default:</span> <code>'start'</code></p>  <p> Defined by <a href="PopupSource">PopupSource</a> </p> 
  

The preferred direction for the popup.

• above: popup appears above the source
• below: popup appears below the source
• column-reverse: popup appears before the source in the block axis
• column: popup appears after the source in the block axis
• left: popup appears to the left of the source
• right: popup appears to the right of the source
• row-reverse: popup appears before the source in the inline axis
• row: popup appears after the source in the inline axis

   <p><span class="apiLabel">Type:</span> <code>'above'|'below'|'column-reverse'|'column'|'left'|'right'|'row-reverse'|'row'</code></p> <p><span class="apiLabel">Default:</span> <code>'column'</code></p>  <p> Defined by <a href="PopupSource">PopupSource</a> </p> 
  

The class or tag used to create the popup part – the element responsible for displaying the popup and handling overlay behavior.

Type: (component class constructor)|HTMLTemplateElement|string

Default: Popup

Defined by PopupSource

The class or tag used to create the popup-toggle part – the element that lets the user know they can open the popup.

Type: (component class constructor)|HTMLTemplateElement|string

Default: UpDownToggle

Defined by PopupToggleMixin

Render the indicated changes in state to the DOM.

The default implementation of this method does nothing. Override this method in your component to update your component's host element and any shadow elements to reflect the component's new state. See the rendering example.

Be sure to call super in your method implementation so that your component's base classes and mixins have a chance to perform their own render work.

Parameters:

• changed: ChangedFlags – dictionary of flags indicating which state members have changed since the last render

Defined by ReactiveMixin

Render any pending component changes to the DOM.

This method does nothing if the state has not changed since the last render call.

ReactiveMixin will invoke this method following a setState call; you should not need to invoke this method yourself.

This method invokes the internal render method, then invokes the rendered method.

Defined by ReactiveMixin

Perform any work that must happen after state changes have been rendered to the DOM.

The default implementation of this method does nothing. Override this method in your component to perform work that requires the component to be fully rendered, such as setting focus on a shadow element or inspecting the computed style of an element. If such work should result in a change in component state, you can safely call setState during the rendered method.

Be sure to call super in your method implementation so that your component's base classes and mixins have a chance to perform their own post-render work.

Parameters:

• changed: ChangedFlags –

Defined by ReactiveMixin

Highlight the current item (if one exists), then close the menu.

Defined by PopupListMixin

The index of the selected item, or -1 if no item is selected.

Type: number

Defined by SingleSelectAPIMixin

Raised when the selectedIndex property changes.

Defined by SingleSelectAPIMixin

The selected item, or null if no item is selected.

Type: Element

Defined by SingleSelectAPIMixin

The text content of the selected item.

Setting this value to a string will attempt to select the first list item whose text matches that string. Setting this to a string not matching any list item will result in no selection.

Type: string

Defined by SelectedTextAPIMixin

Update the component's state by merging the specified changes on top of the existing state. If the component is connected to the document, and the new state has changed, this returns a promise to asynchronously render the component. Otherwise, this returns a resolved promise.

Parameters:

• changes: PlainObject – the changes to apply to the element's state

Returns: Promise - resolves when the new state has been rendered

Defined by ReactiveMixin

The class or tag used to create the source part - the button (or other element) the user can tap/click to invoke the popup.

Type: (component class constructor)|HTMLTemplateElement|string

Default: 'button'

Defined by PopupSource

The component's current state.

The returned state object is immutable. To update it, invoke internal.setState.

It's extremely useful to be able to inspect component state while debugging. If you append ?elixdebug=true to a page's URL, then ReactiveMixin will conditionally expose a public state property that returns the component's state. You can then access the state in your browser's debug console.

Type: PlainObject

Defined by ReactiveMixin

Ask the component whether a state with a set of recently-changed fields implies that additional second-order changes should be applied to that state to make it consistent.

This method is invoked during a call to internal.setState to give all of a component's mixins and classes a chance to respond to changes in state. If one mixin/class updates state that it controls, another mixin/class may want to respond by updating some other state member that it controls.

This method should return a dictionary of changes that should be applied to the state. If the dictionary object is not empty, the internal.setState method will apply the changes to the state, and invoke this stateEffects method again to determine whether there are any third-order effects that should be applied. This process repeats until all mixins/classes report that they have no additional changes to make.

See an example of how ReactiveMixin invokes the stateEffects to ensure state consistency.

Parameters:

• state: PlainObject – a proposal for a new state
• changed: ChangedFlags – the set of fields changed in this latest proposal for the new state

Returns: PlainObject

Defined by ReactiveMixin

Toggle the open/close state of the element.

Parameters:

• opened: boolean – true if the element should be opened, false if closed.

Defined by OpenCloseMixin

The "type" of the form field, provided for consistency with the native HTML type property.

If a base class provides a type property, that will be returned. (If this mixin is applied to a class defined by WrappedStandardElement, this will return the type of the inner standard element.) Otherwise, the default value of this property will be the same as the HTML tag name registered for the custom element.

Type: string

Defined by FormElementMixin

The value attribute of the selected item.

Setting this to a string will attempt to select the first list item whose value attribute matches that string. Setting this to a string not matching any value attribute will result in no selection.

Type: string

Defined by SelectedValueAPIMixin

The class or tag used to create the value part - the region showing the dropdown list's current value.

Type: (component class constructor)|HTMLTemplateElement|string

Default: 'div'

Defined by DropdownList

This method can be used as an alternative to listening to the "openedchange" event, particularly in situations where you want to only handle the next time the component is closed.

Returns: Promise A promise that resolves when the element has completely closed, including the completion of any asynchronous opening effect.

Defined by OpenCloseMixin