Class: Dropdown

Extends

• LuCI.ui.AbstractElement

Methods

addChoices(values, labels)

ui.js, line 1663

Add new choices to the dropdown menu.

This function adds further choices to an existing dropdown menu, ignoring choice values which are already present.

Name	Type	Description
values	Array.<string>	The choice values to add to the dropdown widget.
labels	Object.<string, *>	The choice label values to use when adding dropdown choices. If no label is found for a particular choice value, the value itself is used as label text. Choice labels may be any valid value accepted by LuCI.dom#content.

clearChoices(reset_value)

ui.js, line 1628

Remove all existing choices from the dropdown menu.

This function removes all preexisting dropdown choices from the widget, keeping only choices currently being selected unless reset_values is given, in which case all choices and deselected and removed.

Name	Type	Default	Description
reset_value	boolean	false	optional If set to true, deselect and remove selected choices as well instead of keeping them.

closeAllDropdowns()

ui.js, line 1696

Close all open dropdown widgets in the current document.

inherited getValue(){string|Array.<string>|null}

ui.js, line 1905

Read the current value of the input widget.

Returns:

Type	Description
string | Array.<string> | null	The current value of the input element. For simple inputs like text fields or selects, the return value type will be a - possibly empty - string. Complex widgets such as DynamicList instances may result in an array of strings or null for unset values.

inherited isChanged(){boolean}

ui.js, line 141

Check whether the input value was altered by the user.

Returns:

Type	Description
boolean	Returns true if the input value has been altered by the user or false if it is unchaged. Note that if the user modifies the initial value and changes it back to the original state, it is still reported as changed.

inherited isValid(){boolean}

ui.js, line 154

Check whether the current input value is valid.

Returns:

Type	Description
boolean	Returns true if the current input value is valid or false if it does not meet the validation constraints.

inherited registerEvents(targetNode, synevent, events)

ui.js, line 203

Dispatch a custom (synthetic) event in response to received events.

Sets up event handlers on the given target DOM node for the given event names that dispatch a custom event of the given type to the widget root DOM node.

The primary purpose of this function is to set up a series of custom uniform standard events such as widget-update, validation-success, validation-failure etc. which are triggered by various different widget specific native DOM events.

Name	Type	Description
targetNode	Node	Specifies the DOM node on which the native event listeners should be registered.
synevent	string	The name of the custom event to dispatch to the widget root DOM node.
events	Array.<string>	The native DOM events for which event handlers should be registered.

inherited render(){Node}

ui.js, line 1016

Render the widget, setup event listeners and return resulting markup.

Returns:

Type	Description
Node	Returns a DOM Node or DocumentFragment containing the rendered widget markup.

inherited setChangeEvents(targetNode, events)

ui.js, line 271

Setup listeners for native DOM events that may change the widget value.

Sets up event handlers on the given target DOM node for the given event names which may cause the input value to change completely, such as change events in a select menu. In contrast to update events, such change events will not trigger input value validation but they may cause field dependencies to get re-evaluated and will mark the input widget as dirty.

Name	Type	Description
targetNode	Node	Specifies the DOM node on which the event listeners should be registered.
events	string	repeatable The DOM events for which event handlers should be registered.

inherited setPlaceholder(value)

ui.js, line 113

Set the current placeholder value of the input widget.

Name	Type	Description
value	string | Array.<string> | null	The placeholder to set for the input element. Only applicable to text inputs, not to radio buttons, selects or similar.

inherited setUpdateEvents(targetNode, events)

ui.js, line 228

Setup listeners for native DOM events that may update the widget value.

Sets up event handlers on the given target DOM node for the given event names which may cause the input value to update, such as keyup or onclick events. In contrast to change events, such update events will trigger input value validation.

Name	Type	Description
targetNode	Node	Specifies the DOM node on which the event listeners should be registered.
events	string	repeatable The DOM events for which event handlers should be registered.

inherited setValue(value)

ui.js, line 1878

Set the current value of the input widget.

Name	Type	Description
value	string | Array.<string> | null	The value to set the input element to. For simple inputs like text fields or selects, the value should be a - possibly empty - string. Complex widgets such as DynamicList instances may accept string array or null values.

inherited triggerValidation()

ui.js, line 168

Force validation of the current input value.

Usually input validation is automatically triggered by various DOM events bound to the input widget. In some cases it is required though to manually trigger validation runs, e.g. when programmatically altering values.

Type Definitions

LuCI.ui.Dropdown.InitOptionsLuCI.ui.AbstractElement.InitOptions

In addition to the AbstractElement.InitOptions the following properties are recognized:

Properties:

Name	Type	Argument	Default	Description
optional	boolean	<optional>	true	Specifies whether the dropdown selection is optional. In contrast to other widgets, the optional constraint of dropdowns works differently; instead of marking the widget invalid on empty values when set to false, the user is not allowed to deselect all choices. For single value dropdowns that means that no empty "please select" choice is offered and for multi value dropdowns, the last selected choice may not be deselected without selecting another choice first.
multiple	boolean	<optional>		Specifies whether multiple choice values may be selected. It defaults to true when an array is passed as input value to the constructor.
sort	boolean | Array.<string>	<optional>	false	Specifies if and how to sort choice values. If set to true, the choice values will be sorted alphabetically. If set to an array of strings, the choice sort order is derived from the array.
select_placeholder	string	<optional>	-- Please choose --	Specifies a placeholder text which is displayed when no choice is selected yet.
custom_placeholder	string	<optional>	-- custom --	Specifies a placeholder text which is displayed in the text input field allowing to enter custom choice values. Only applicable if the create option is set to true.
create	boolean	<optional>	false	Specifies whether custom choices may be entered into the dropdown widget.
create_query	string	<optional>	.create-item-input	Specifies a CSS selector expression used to find the input element which is used to enter custom choice values. This should not normally be used except by widgets derived from the Dropdown class.
create_template	string	<optional>	script[type="item-template"]	Specifies a CSS selector expression used to find an HTML element serving as template for newly added custom choice values. Any {{value}} placeholder string within the template elements text content will be replaced by the user supplied choice value, the resulting string is parsed as HTML and appended to the end of the choice list. The template markup may specify one HTML element with a data-label-placeholder attribute which is replaced by a matching label value from the choices object or with the user supplied value itself in case choices contains no matching choice label. If the template element is not found or if no create_template selector expression is specified, the default markup for newly created elements is <li data-value="{{value}}"><span data-label-placeholder="true" /></li>.
create_markup	string	<optional>		This property allows specifying the markup for custom choices directly instead of referring to a template element through CSS selectors. Apart from that it works exactly like create_template.
display_items	number	<optional>	3	Specifies the maximum amount of choice labels that should be shown in collapsed dropdown state before further selected choices are cut off. Only applicable when multiple is true.
dropdown_items	number	<optional>	-1	Specifies the maximum amount of choices that should be shown when the dropdown is open. If the amount of available choices exceeds this number, the dropdown area must be scrolled to reach further items. If set to -1, the dropdown menu will attempt to show all choice values and only resort to scrolling if the amount of choices exceeds the available screen space above and below the dropdown widget.
placeholder	string	<optional>		This property serves as a shortcut to set both select_placeholder and custom_placeholder. Either of these properties will fallback to placeholder if not specified.
readonly	boolean	<optional>	false	Specifies whether the custom choice input field should be rendered readonly. Only applicable when create is true.
maxlength	number	<optional>		Specifies the HTML maxlength attribute to set on the custom choice <input> element. Note that this a legacy property that exists for compatibility reasons. It is usually better to maxlength(N) validation expression. Only applicable when create is true.