Class: Hiddenfield

LuCI.ui. Hiddenfield

The Hiddenfield class implements an HTML <input type="hidden"> field which allows to store form data without exposing it to the user.

UI widget instances are usually not supposed to be created by view code directly, instead they're implicitly created by LuCI.form when instantiating CBI forms.

This class is automatically instantiated as part of LuCI.ui. To use it in views, use 'require ui' and refer to ui.Hiddenfield. To import it in external JavaScript, use L.require("ui").then(...) and access the Hiddenfield property of the class instance value.

new LuCI.ui.Hiddenfield(value, options)

Instantiate a hidden input field widget.

Name Type Default Description
value string | Array.<string> null optional

The initial input value.

options LuCI.ui.AbstractElement.InitOptions optional

Object describing the widget specific options to initialize the hidden input.

Extends

Methods

inherited getValidationError(){string}

Returns the current validation error

Returns:
Type Description
string The validation error at this time

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

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}

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 unchanged. 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}

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)

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}

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)

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)

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)

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)

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()

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.