ASP.NET Core MVC Controls | ComponentOne
In This Topic
    DropDown Class
    In This Topic
    File
    wijmo.input.js
    Module
    wijmo.input
    Base Class
    Control
    Derived Classes
    ComboBox, InputColor, InputDate

    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).

    Constructor

    constructor

    constructor(element: any, options?: any): DropDown
    

    Initializes a new instance of the DropDown class.

    Parameters
    • element: any

      The DOM element that hosts the control, or a selector for the host element (e.g. '#theCtrl').

    • options: any Optional

      The JavaScript object containing initialization data for the control.

    Returns
    DropDown

    Properties

    autoExpandSelection

    Gets or sets a value that indicates whether the control should automatically expand the selection to whole words/numbers when the control is clicked.

    The default value for this property is **true**.

    Type
    boolean

    clickAction

    Gets or sets a value that specifies the action to perform when the user clicks the input element in the control.

    For most drop-down controls, this property is set to Select by default. This setting allows users to select portions of the text with the mouse.

    For drop-down controls that display non-editable text (such as the MultiSelect), this property is set to Toggle by default.

    Type
    ClickAction

    Static controlTemplate

    Gets or sets the template used to instantiate DropDown controls.

    Type
    any

    hostElement

    Gets the DOM element that is hosting the control.

    Inherited From
    Control
    Type
    HTMLElement

    inputElement

    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.

    Type
    HTMLInputElement

    inputType

    Gets or sets the "type" attribute of the HTML input element hosted by the control.

    The default value for this property is **'text'**.

    Type
    string

    isAnimated

    Gets or sets a value that indicates whether the control should use a fade-in animation when displaying the drop-down.

    The default value for this property is **false**.

    Type
    boolean

    isDisabled

    Gets or sets a value that determines whether the control is disabled.

    Disabled controls cannot get mouse or keyboard events.

    Inherited From
    Control
    Type
    boolean

    isDroppedDown

    Gets or sets a value that indicates whether the drop down is currently visible.

    The default value for this property is **false**.

    Type
    boolean

    isReadOnly

    Gets or sets a value that indicates whether the user can modify the control value using the mouse and keyboard.

    The default value for this property is **false**.

    Type
    boolean

    isRequired

    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).

    This property defaults to true for most controls, including ComboBox, InputDate, InputTime, InputDateTime, and InputColor. It defaults to false for the AutoComplete control.

    Type
    boolean

    isTouching

    Gets a value that indicates whether the control is currently handling a touch event.

    Inherited From
    Control
    Type
    boolean

    isUpdating

    Gets a value that indicates whether the control is currently being updated.

    Inherited From
    Control
    Type
    boolean

    placeholder

    Gets or sets the string shown as a hint when the control is empty.

    Type
    string

    rightToLeft

    Gets a value indicating whether the control is hosted in an element with right-to-left layout.

    Inherited From
    Control
    Type
    boolean

    showDropDownButton

    Gets or sets a value that indicates whether the control should display a drop-down button.

    The default value for this property is **true**.

    Type
    boolean

    tabOrder

    Gets or sets a value of the **tabindex** attribute associated with the control.

    **tabindex** attribute value can be defined statically for a Wijmo control by specifying it on the control's host HTML element. But this value can't be changed later during application lifecycle, because Wijmo controls have complex structure, and the control may need to propagate this attribute value to its internal element to work properly.

    Because of this, to read or change control's **tabindex** dynamically, you should do it using this property.

    Inherited From
    Control
    Type
    number

    text

    Gets or sets the text shown on the control.

    Type
    string

    Methods

    addEventListener

    addEventListener(target: EventTarget, type: string, fn: any, capture?: boolean, passive?: 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 methods).

    Failing to remove event listeners may cause memory leaks.

    The passive parameter is set to false by default, which means the event handler may call event.preventDefault(). If you are adding passive handlers to touch or wheel events, setting this parameter to true will improve application performance.

    For details on passive event listeners, please see Improving scrolling performance with passive listeners.

    Parameters
    • target: EventTarget

      Target element for the event.

    • type: string

      String that specifies the event.

    • fn: any

      Function to execute when the event occurs.

    • capture: boolean Optional

      Whether the listener should be handled by the control before it is handled by the target element.

    • passive: boolean Optional

      Indicates that the handler will never call preventDefault().

    Inherited From
    Control
    Returns
    void

    applyTemplate

    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. Therefore, this method is not available. 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', templateString, {
      _tbx: 'input',
      _btnUp: 'btn-inc',
      _btnDn: 'btn-dec'
    }, 'input');
    
    
    ```

    Parameters
    • classNames: string

      Names of classes to add to the control's host element.

    • template: string

      An HTML string that defines the control template.

    • parts: Object

      A dictionary of part variables and their names.

    • namePart: string Optional

      Name of the part to be named after the host element. This determines how the control submits data when used in forms.

    Inherited From
    Control
    Returns
    HTMLElement

    beginUpdate

    beginUpdate(): void
    

    Suspends notifications until the next call to endUpdate.

    Inherited From
    Control
    Returns
    void

    containsFocus

    containsFocus(): boolean
    

    Checks whether this control contains the focused element.

    Inherited From
    Control
    Returns
    boolean

    deferUpdate

    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.

    Parameters
    Inherited From
    Control
    Returns
    void

    dispose

    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.

    Inherited From
    Control
    Returns
    void

    Static disposeAll

    disposeAll(e?: HTMLElement): void
    

    Disposes of all Wijmo controls contained in an HTML element.

    Parameters
    Inherited From
    Control
    Returns
    void

    endUpdate

    endUpdate(shouldInvalidate?: boolean): void
    

    Resumes notifications suspended by calls to beginUpdate.

    Parameters
    • shouldInvalidate: boolean Optional

      should invalidate the control. Default value for this parameter is true.

    Inherited From
    Control
    Returns
    void

    focus

    focus(): void
    

    Sets the focus to this control.

    Inherited From
    Control
    Returns
    void

    Static getControl

    getControl(element: any): Control
    

    Gets the control that is hosted in a given DOM element.

    Parameters
    • element: any

      The DOM element that hosts the control, or a CSS selector for the host element (e.g. '#theCtrl').

    Inherited From
    Control
    Returns
    Control

    getTemplate

    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, which does not specify a template, it will override the template defined by the DropDown base class (the nearest ancestor that does specify a template).

    Inherited From
    Control
    Returns
    string

    initialize

    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.

    Parameters
    • options: any

      Object that contains the initialization data.

    Inherited From
    Control
    Returns
    void

    invalidate

    invalidate(fullUpdate?: boolean): void
    

    Invalidates the control causing an asynchronous refresh.

    Parameters
    • fullUpdate: boolean Optional

      Whether to update the control layout as well as the content.

    Inherited From
    Control
    Returns
    void

    Static invalidateAll

    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.

    Parameters
    • e: HTMLElement Optional

      Container element. If set to null, all Wijmo controls on the page will be invalidated.

    Inherited From
    Control
    Returns
    void

    onGotFocus

    onGotFocus(e?: EventArgs): void
    

    Raises the gotFocus event.

    Parameters
    Inherited From
    Control
    Returns
    void

    onInvalidInput

    onInvalidInput(e: CancelEventArgs): void
    

    Raises the invalidInput event.

    If the event handler cancels the event, the control will keep the invalid input and the focus.

    Parameters
    Inherited From
    Control
    Returns
    void

    onIsDroppedDownChanged

    onIsDroppedDownChanged(e?: EventArgs): void
    

    Raises the isDroppedDownChanged event.

    Parameters
    Returns
    void

    onIsDroppedDownChanging

    onIsDroppedDownChanging(e: CancelEventArgs): boolean
    

    Raises the isDroppedDownChanging event.

    Parameters
    Returns
    boolean

    onLostFocus

    onLostFocus(e?: EventArgs): void
    

    Raises the lostFocus event.

    Parameters
    Inherited From
    Control
    Returns
    void

    onRefreshed

    onRefreshed(e?: EventArgs): void
    

    Raises the refreshed event.

    Parameters
    Inherited From
    Control
    Returns
    void

    onRefreshing

    onRefreshing(e?: EventArgs): void
    

    Raises the refreshing event.

    Parameters
    Inherited From
    Control
    Returns
    void

    onTextChanged

    onTextChanged(e?: EventArgs): void
    

    Raises the textChanged event.

    Parameters
    Returns
    void

    refresh

    refresh(fullUpdate?: boolean): void
    

    Refreshes the control.

    Parameters
    • fullUpdate: boolean Optional

      Whether to update the control layout as well as the content.

    Inherited From
    Control
    Returns
    void

    Static refreshAll

    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.

    Parameters
    • e: HTMLElement Optional

      Container element. If set to null, all Wijmo controls on the page will be invalidated.

    Inherited From
    Control
    Returns
    void

    removeEventListener

    removeEventListener(target?: EventTarget, type?: string, fn?: any, capture?: boolean): number
    

    Removes one or more event listeners attached to elements owned by this Control.

    Parameters
    • target: EventTarget Optional

      Target element for the event. If null, removes listeners attached to all targets.

    • type: string Optional

      String that specifies the event. If null, removes listeners attached to all events.

    • fn: any Optional

      Handler to remove. If null, removes all handlers.

    • capture: boolean Optional

      Whether the listener is capturing. If null, removes capturing and non-capturing listeners.

    Inherited From
    Control
    Returns
    number

    selectAll

    selectAll(): void
    

    Sets the focus to the control and selects all its content.

    Returns
    void

    Events

    gotFocus

    Occurs when the control gets the focus.

    Inherited From
    Control
    Arguments
    EventArgs

    invalidInput

    Occurs when invalid input is detected.

    Invalid input may occur when the user types or pastes a value that cannot be converted to the proper type, or a value that is outside the valid range.

    If the event handler cancels the event, the control will retain the invalid content and the focus, so users can correct the error.

    If the event is not canceled, the control will ignore the invalid input and will retain the original content.

    Inherited From
    Control
    Arguments
    CancelEventArgs

    isDroppedDownChanged

    Occurs after the drop down is shown or hidden.

    Arguments
    EventArgs

    isDroppedDownChanging

    Occurs before the drop down is shown or hidden.

    Arguments
    CancelEventArgs

    lostFocus

    Occurs when the control loses the focus.

    Inherited From
    Control
    Arguments
    EventArgs

    refreshed

    Occurs after the control has refreshed its contents.

    Inherited From
    Control
    Arguments
    EventArgs

    refreshing

    Occurs when the control is about to refresh its contents.

    Inherited From
    Control
    Arguments
    EventArgs

    textChanged

    Occurs when the value of the text property changes.

    Arguments
    EventArgs