| Client-Side API Reference > Input > wijmo.input > DropDown Class |
constructor(element: any, options?): DropDown
Initializes a new instance of the DropDown class.
The DOM element that hosts the control, or a selector for the host element (e.g. '#theCtrl').
The JavaScript object containing initialization data for the control.
Gets or sets a value that indicates whether the control should automatically expand the selection to whole words/numbers when the control is clicked.
Gets the drop down element shown when the isDroppedDown property is set to true.
Gets or sets a CSS class name to add to the control's drop-down element.
This property is useful when styling the drop-down element, because it is shown as a child of the document body rather than as a child of the control itself, which prevents using CSS selectors based on the parent control.
Gets the DOM element that is hosting the control.
Gets the HTML input element hosted by the control.
Use this property in situations where you want to customize the attributes of the input element.
Gets or sets a value that indicates whether the control should use a fade-in animation when displaying the drop-down.
Gets or sets a value that determines whether the control is disabled.
Disabled controls cannot get mouse or keyboard events.
Gets or sets a value that indicates whether the drop down is currently visible.
Gets or sets a value that indicates whether the user can modify the control value using the mouse and keyboard.
Gets or sets a value that determines whether the control value must be set to a non-null value or whether it can be set to null (by deleting the content of the control).
Gets a value that indicates whether the control is currently handling a touch event.
Gets a value that indicates whether the control is currently being updated.
Gets a value indicating whether the control is hosted in an element with right-to-left layout.
Gets or sets a value that indicates whether the control should display a drop-down button.
addEventListener(target: EventTarget, type: string, fn: any, capture?: boolean): void
Adds an event listener to an element owned by this Control.
The control keeps a list of attached listeners and their handlers, making it easier to remove them when the control is disposed (see the dispose and removeEventListener method).
Failing to remove event listeners may cause memory leaks.
Target element for the event.
String that specifies the event.
Function to execute when the event occurs.
Whether the listener is capturing.
applyTemplate(classNames: string, template: string, parts: Object, namePart?: string): HTMLElement
Applies the template to a new instance of a control, and returns the root element.
This method should be called by constructors of templated controls. It is responsible for binding the template parts to the corresponding control members.
For example, the code below applies a template to an instance of an InputNumber control. The template must contain elements with the 'wj-part' attribute set to 'input', 'btn-inc', and 'btn-dec'. The control members '_tbx', '_btnUp', and '_btnDn' will be assigned references to these elements.
this.applyTemplate('wj-control wj-inputnumber', template, {
_tbx: 'input',
_btnUp: 'btn-inc',
_btnDn: 'btn-dec'
}, 'input');
Names of classes to add to the control's host element.
An HTML string that defines the control template.
A dictionary of part variables and their names.
Name of the part to be named after the host element. This determines how the control submits data when used in forms.
beginUpdate(): void
Suspends notifications until the next call to endUpdate.
deferUpdate(fn: Function): void
Executes a function within a beginUpdate/endUpdate block.
The control will not be updated until the function has been executed. This method ensures endUpdate is called even if the function throws an exception.
Function to be executed.
dispose(): void
Disposes of the control by removing its association with the host element.
The dispose method automatically removes any event listeners added with the addEventListener method.
Calling the dispose method is important in applications that create and remove controls dynamically. Failing to dispose of the controls may cause memory leaks.
disposeAll(e?: HTMLElement): void
Disposes of all Wijmo controls contained in an HTML element.
Container element.
endUpdate(): void
Resumes notifications suspended by calls to beginUpdate.
getControl(element: any): Control
Gets the control that is hosted in a given DOM element.
The DOM element that is hosting the control, or a selector for the host element (e.g. '#theCtrl').
getTemplate(): string
Gets the HTML template used to create instances of the control.
This method traverses up the class hierarchy to find the nearest ancestor that specifies a control template. For example, if you specify a prototype for the ComboBox control, it will override the template defined by the DropDown base class.
initialize(options: any): void
Initializes the control by copying the properties from a given object.
This method allows you to initialize controls using plain data objects instead of setting the value of each property in code.
For example:
grid.initialize({
itemsSource: myList,
autoGenerateColumns: false,
columns: [
{ binding: 'id', header: 'Code', width: 130 },
{ binding: 'name', header: 'Name', width: 60 }
]
});
// is equivalent to
grid.itemsSource = myList;
grid.autoGenerateColumns = false;
// etc.
The initialization data is type-checked as it is applied. If the initialization object contains unknown property names or invalid data types, this method will throw.
Object that contains the initialization data.
invalidate(fullUpdate?: boolean): void
Invalidates the control causing an asynchronous refresh.
Whether to update the control layout as well as the content.
invalidateAll(e?: HTMLElement): void
Invalidates all Wijmo controls contained in an HTML element.
Use this method when your application has dynamic panels that change the control's visibility or dimensions. For example, splitters, accordions, and tab controls usually change the visibility of its content elements. In this case, failing to notify the controls contained in the element may cause them to stop working properly.
If this happens, you must handle the appropriate event in the dynamic container and call the invalidateAll method so the contained Wijmo controls will update their layout information properly.
Container element. If set to null, all Wijmo controls on the page will be invalidated.
onGotFocus(e?: EventArgs): void
Raises the gotFocus event.
onIsDroppedDownChanged(e?: EventArgs): void
Raises the isDroppedDownChanged event.
onIsDroppedDownChanging(e: CancelEventArgs): boolean
Raises the isDroppedDownChanging event.
onLostFocus(e?: EventArgs): void
Raises the lostFocus event.
onTextChanged(e?: EventArgs): void
Raises the textChanged event.
refresh(fullUpdate?: boolean): void
Refreshes the control.
Whether to update the control layout as well as the content.
refreshAll(e?: HTMLElement): void
Refreshes all Wijmo controls contained in an HTML element.
This method is similar to invalidateAll, except the controls are updated immediately rather than after an interval.
Container element. If set to null, all Wijmo controls on the page will be invalidated.
removeEventListener(target?: EventTarget, type?: string, fn?: any, capture?: boolean): number
Removes one or more event listeners attached to elements owned by this Control.
Target element for the event. If null, removes listeners attached to all targets.
String that specifies the event. If null, removes listeners attached to all events.
Handler to remove. If null, removes all handlers.
Whether the listener is capturing. If null, removes capturing and non-capturing listeners.
selectAll(): void
Sets the focus to the control and selects all its content.
DropDown control (abstract).
Contains an input element and a button used to show or hide the drop-down.
Derived classes must override the _createDropDown method to create whatever editor they want to show in the drop down area (a list of items, a calendar, a color editor, etc).