Configuration

An object defining configuration options for the DropDownBox widget.

acceptCustomValue

Specifies whether the widget allows a user to enter a custom value.

Type: Boolean
Default Value: false

accessKey

Specifies the shortcut key that sets focus on the widget.

Type: String
Default Value: null

The value of this option will be passed to the accesskey attribute of the HTML element that underlies the widget.

activeStateEnabled

Specifies whether or not the widget changes its state when interacting with a user.

Type: Boolean
Default Value: true

This option is used when the widget is displayed on a platform whose guidelines include the active state change for widgets.

contentTemplate

Specifies a custom template for the drop-down content.

Type: template
Function parameters:
templateData: Object
Data associated with the widget.
contentElement: jQuery
The content element.
Return Value: String|DOM Node|jQuery
A template's name or container.
Default Value: null

Below is the list of fields passed in the templateData object.

  • value: Any
    The currently selected value.
  • component: jQuery
    The widget instance.

If you use the Knockout or AngularJS library, you can implement this template with the dxTemplate markup component. The template is in the binding context of the view model. Therefore, you can bind template elements directly to the properties of the view model. To access another binding context from the template, use the Knockout or AngularJS binding variables.

dataSource

A data source used to fetch data to be displayed by the widget.

Default Value: null

This option accepts one of the following.

  • Array of objects
    A simple JavaScript array containing a collection of plain objects.

  • URL
    A URL to JSON data or to a service returning data in JSON format.

  • DataSource or its configuration object
    A DataSource is an object that provides a handy API for data processing. A DataSource is a stateful object, which means that it saves data processing settings and applies them each time data is loaded. All underlying data access logic of a DataSource is isolated in a Store. A Store provides an API for reading and modifying data. Unlike the DataSource, a Store is a stateless object.

NOTE
If the data source is specified using the dataSource option, use the items option only for reading. Updating data items using the items option may cause unexpected results.

deferRendering

Specifies whether widget content is rendered when the widget is shown or when rendering the widget.

Type: Boolean
Default Value: true

If this option is set to true, widget content is rendered when showing the widget. Otherwise, widget content is rendered when rendering the widget.

disabled

Specifies whether the widget responds to user interaction.

Type: Boolean
Default Value: false

displayExpr

Specifies the name of the data source item field whose value is displayed by the widget.

Type: String| function
Default Value: undefined

If the data source item is a simple object holding a value (string, numeric, Boolean, etc.), assign 'this' to the displayExpr option. If the item is a plain object item, assign the required field name or path to the option.

dropDownButtonTemplate

Specifies a custom template for the drop-down button.

Type: template
Function parameters:
buttonData: Object
An object holding the button data.
Object structure:
text: String
The button's text.
icon: String
The button's icon.
contentElement: jQuery
The button's element.
Return Value: String|jQuery
A template's name or container.
Default Value: 'dropDownButton'

If you use the Knockout or AngularJS library, you can implement this template with the dxTemplate markup component. The template is in the binding context of the view model. Therefore, you can bind template elements directly to the properties of the view model. To access another binding context from the template, use the Knockout or AngularJS binding variables.

See Also

dropDownOptions

Configures the drop-down field which holds the content.

Default Value: {}

See Popup Configuration for options that you can specify in this object.

elementAttr

Specifies the attributes to be attached to the widget's root element.

Type: Object
Default Value: {}

When you configure this option in an ASP.NET MVC Control, pass a dictionary as shown in the following code.

Razor C#
Razor VB
@(Html.DevExtreme()
    // other widget options
    // ...
    .ElementAttr(new Dictionary<string, object>() {
        { "id", "elementId" },
        { "class", "class-name" },
        // ...
    })
)
@(Html.DevExtreme().WidgetName() _
    .ElementAttr(New Dictionary(Of String, Object) From {
        { "id", "elementId" },
        { "class", "class-name" }
    })
)

focusStateEnabled

Specifies whether the widget can be focused using keyboard navigation.

Type: Boolean
Default Value: true

height

Specifies the height of the widget.

Type: Number|String| function
Return Value: Number|String
The height of the widget.
Default Value: undefined

This option accepts a value of one of the following types.

  • Number
    The height of the widget in pixels.

  • String
    A CSS-accepted measurement of height. For example, "55px", "80%", "auto", "inherit".

  • Function
    A function returning either of the above. For example:

    JavaScript
    height: function() {
        return window.innerHeight / 1.5;
    }

hint

Specifies text for a hint that appears when a user pauses on the widget.

Type: String
Default Value: undefined

hoverStateEnabled

Specifies whether the widget changes its state when a user pauses on it.

Type: Boolean
Default Value: true

inputAttr

Specifies the attributes to be passed on to the underlying HTML element.

Type: Object
Default Value: {}

When you configure this option in ASP.NET MVC Controls, pass a dictionary as shown in the following code.

Razor C#
Razor VB
@(Html.DevExtreme()
    // other widget options
    // ...
    .InputAttr(new Dictionary<string, object>() {
        { "id", "inputId" },
        // ...
    })
)
@(Html.DevExtreme().WidgetName() _
    .InputAttr(New Dictionary(Of String, Object) From {
        { "id", "inputId" }
    })
)

isValid

Specifies whether the editor's value is valid.

Type: Boolean
Default Value: true

In Knockout apps, you may need to inform a user about an error that occurred during the validation of a view model field. For this purpose, set the editor's isValid option to the isValid value of the dxValidator that validates this field. To show an error message, set the editor's validationError option to the dxValidator's validationError value.

JavaScript
var editorValue = ko.observable("").extend({
    dxValidator: {
        validationRules: [{
            type: 'required',
            message: 'Specify this value'
        }]
    }
});
var viewModel = {
    editorOptions: {
        value: editorValue,
        isValid: editorValue.dxValidator.isValid,
        validationError: editorValue.dxValidator.validationError
    }
};

The editor's isValid and validationError options should also be specified when using a custom validation engine. In this instance, the validation result will be displayed for the editor by the means of the DevExtreme Validation UI.

See Also

items

An array of items displayed by the widget.

Type: Array

You can use the dataSource option instead. Unlike the items option, the dataSource option can take on the DataSource configuration object as well as a simple array.

NOTE
If you need to modify the data source specified using the items option at runtime, do it only with the help of the items option. Updating data items using the dataSource option may cause unexpected results.

name

The value to be assigned to the name attribute of the underlying HTML element.

Type: String
Default Value: ''

Specify this option if the widget lies within an HTML form that will be submitted.

If you configure the widget as an ASP.NET MVC Control, use this option to bind the widget to a model property. If this model property contains Data Annotation validation attributes, you get the client-side validation enabled by default.

onChange

A handler for the change event.

Type: function
Function parameters:
Provides function parameters.
Object structure:
component: Object
Provides access to the widget instance.
element: jQuery
An HTML element of the widget.
model: Object
Provides access to the data that is available for binding against the element. Available only in the Knockout approach.
jQueryEvent: jQuery.Event
Specifies the jQuery event that caused action execution.
Default Value: null

Assign a function to perform a custom action when a change within the widget's input element is committed by an end user.

onClosed

A handler for the closed event.

Type: function
Function parameters:
Provides function parameters.
Object structure:
component: Object
Provides access to the widget instance.
element: jQuery
An HTML element of the widget.
model: Object
Provides access to the data that is available for binding against the element. Available only in the Knockout approach.
Default Value: null

Assign a function to perform a custom action after a drop-down editor has been hidden.

onCopy

A handler for the copy event.

Type: function
Function parameters:
Provides function parameters.
Object structure:
component: Object
Provides access to the widget instance.
element: jQuery
An HTML element of the widget.
model: Object
Provides access to the data that is available for binding against the element. Available only in the Knockout approach.
jQueryEvent: jQuery.Event
Specifies the jQuery event that caused the action execution.
Default Value: null

Assign a function to perform a custom action after the widget's input is copied.

onCut

A handler for the cut event.

Type: function
Function parameters:
Provides function parameters.
Object structure:
component: Object
Provides access to the widget instance.
element: jQuery
An HTML element of the widget.
model: Object
Provides access to the data that is available for binding against the element. Available only in the Knockout approach.
jQueryEvent: jQuery.Event
Specifies the jQuery event that caused the action execution.
Default Value: null

Assign a function to perform a custom action after the widget's input is cut.

onDisposing

A handler for the disposing event. Executed when the widget is removed from the DOM using the remove(), empty(), or html() jQuery methods only.

Type: function
Function parameters:
Information about the event.
Object structure:
component: Object
The widget instance.
element: jQuery
The widget's container.
model: Object
The model data. Available only if you use Knockout.
Default Value: null

onEnterKey

A handler for the enterKey event.

Type: function
Function parameters:
Provides function parameters.
Object structure:
component: Object
Provides access to the widget instance.
element: jQuery
An HTML element of the widget.
model: Object
Provides access to the data that is available for binding against the element. Available only in the Knockout approach.
jQueryEvent: jQuery.Event
Specifies the jQuery event that caused the action execution.
Default Value: null

Assign a function to perform a custom action after the 'Enter' key is pressed within the widget's input element.

onFocusIn

A handler for the focusIn event.

Type: function
Function parameters:
Provides function parameters.
Object structure:
component: Object
Provides access to the widget instance.
element: jQuery
An HTML element of the widget.
model: Object
Provides access to the data that is available for binding against the element. Available only in the Knockout approach.
jQueryEvent: jQuery.Event
Specifies the jQuery event that caused the action execution.
Default Value: null

Assign a function to perform a custom action after the widget's input is focused.

onFocusOut

A handler for the focusOut event.

Type: function
Function parameters:
Provides function parameters.
Object structure:
component: Object
Provides access to the widget instance.
element: jQuery
An HTML element of the widget.
model: Object
Provides access to the data that is available for binding against the element. Available only in the Knockout approach.
jQueryEvent: jQuery.Event
Specifies the jQuery event that caused the action execution.
Default Value: null

Assign a function to perform a custom action after the widget's input element loses focus.

onInitialized

A handler for the initialized event. Executed only once, after the widget is initialized.

Type: function
Function parameters:
Information about the event.
Object structure:
component: Object
The widget instance.
element: jQuery
The widget's container.
Default Value: null

You cannot access elements in the widget because this handler is executed before they are ready. Use the onContentReady handler instead.

onInput

A handler for the input event.

Type: function
Function parameters:
Provides function parameters.
Object structure:
component: Object
Provides access to the widget instance.
element: jQuery
An HTML element of the widget.
model: Object
Provides access to the data that is available for binding against the element. Available only in the Knockout approach.
jQueryEvent: jQuery.Event
Specifies the jQuery event that caused action execution.
Default Value: null

Assign a function to perform a custom action when a value within the widget's input element is changed by an end user.

onKeyDown

A handler for the keyDown event.

Type: function
Function parameters:
Provides function parameters.
Object structure:
component: Object
Provides access to the widget instance.
element: jQuery
An HTML element of the widget.
model: Object
Provides access to the data that is available for binding against the element. Available only in the Knockout approach.
jQueryEvent: jQuery.Event
Specifies the jQuery event that caused action execution.
Default Value: null

Assign a function to perform a custom action when a key is pressed down within the widget's input element.

onKeyPress

A handler for the keyPress event.

Type: function
Function parameters:
Provides function parameters.
Object structure:
component: Object
Provides access to the widget instance.
element: jQuery
An HTML element of the widget.
model: Object
Provides access to the data that is available for binding against the element. Available only in the Knockout approach.
jQueryEvent: jQuery.Event
Specifies the jQuery event that caused the action execution.
Default Value: null

Assign a function to perform a custom action when the keypress DOM event is raised for the current input element.

onKeyUp

A handler for the keyUp event.

Type: function
Function parameters:
Provides function parameters.
Object structure:
component: Object
Provides access to the widget instance.
element: jQuery
An HTML element of the widget.
model: Object
Provides access to the data that is available for binding against the element. Available only in the Knockout approach.
jQueryEvent: jQuery.Event
Specifies the jQuery event that caused action execution.
Default Value: null

Assign a function to perform a custom action when a key is released within the widget's input element.

onOpened

A handler for the opened event.

Type: function
Function parameters:
Provides function parameters.
Object structure:
component: Object
Provides access to the widget instance.
element: jQuery
An HTML element of the widget.
model: Object
Provides access to the data that is available for binding against the element. Available only in the Knockout approach.
Default Value: null

Assign a function to perform a custom action when the drop-down editor is shown.

onOptionChanged

A handler for the optionChanged event. Executed after an option of the widget is changed.

Type: function
Function parameters:
Information about the event.
Object structure:
component: Object
The widget instance.
name: String
A short name of the option whose value has been changed.
fullName: String
A full name of the option whose value has been changed; contains a full hierarchy of the option.
value: any
A new value for the option.
element: jQuery
The widget's container.
model: Object
The model data. Available only if you use Knockout.
Default Value: null

onPaste

A handler for the paste event.

Type: function
Function parameters:
Provides function parameters.
Object structure:
component: Object
Provides access to the widget instance.
element: jQuery
An HTML element of the widget.
model: Object
Provides access to the data that is available for binding against the element. Available only in the Knockout approach.
jQueryEvent: jQuery.Event
Specifies the jQuery event that caused the action execution.
Default Value: null

Assign a function to perform a custom action after the widget's input is pasted.

onValueChanged

A handler for the valueChanged event.

Type: function
Function parameters:
Provides function parameters.
Object structure:
component: Object
Provides access to the widget instance.
element: jQuery
An HTML element of the widget.
model: Object
Provides access to the data that is available for binding against the element. Available only in the Knockout approach.
value: Object
The widget's new value.
previousValue: Object
The widget's previous value.
jQueryEvent: jQuery.Event
Specifies the jQuery event that caused action execution.
Default Value: null

Assign a function to perform a custom action when the editor value changes.

opened

Specifies whether or not the drop-down editor is displayed.

Type: Boolean
Default Value: false

placeholder

The text displayed by the widget when the widget value is empty.

Type: String
Default Value: ''

readOnly

A Boolean value specifying whether or not the widget is read-only.

Type: Boolean
Default Value: false

rtlEnabled

Switches the widget to a right-to-left representation.

Type: Boolean
Default Value: false

When this option is set to true, the widget text flows from right to left, and the layout of elements is reversed. To switch the entire application/site to the right-to-left representation, assign true to the rtlEnabled field of the object passed to the DevExpress.config(config) method.

JavaScript
DevExpress.config({
    rtlEnabled: true
});

showClearButton

Specifies whether to display the Clear button in the widget.

Type: Boolean
Default Value: false

The Clear button sets the widget value to null.

tabIndex

Specifies the number of the element when the Tab key is used for navigating.

Type: Number
Default Value: 0

The value of this option will be passed to the tabindex attribute of the HTML element that underlies the widget.

text

The read-only option that holds the text displayed by the widget input element.

Type: String
Read-only

validationError

Holds the object that defines the error that occurred during validation.

Type: Object
Default Value: undefined

In Knockout apps, you may need to inform a user about an error that occurred during the validation of a view model field. For this purpose, set the editor's isValid option to the isValid value of the dxValidator that validates this field. To show an error message, set the editor's validationError option to the dxValidator's validationError value.

JavaScript
var editorValue = ko.observable("").extend({
    dxValidator: {
        validationRules: [{
            type: 'required',
            message: 'Specify this value'
        }]
    }
});
var viewModel = {
    editorOptions: {
        value: editorValue,
        isValid: editorValue.dxValidator.isValid,
        validationError: editorValue.dxValidator.validationError
    }
};

The editor's isValid and validationError options should also be specified when using a custom validation engine. In this instance, the validation result will be displayed for the editor by the means of the DevExtreme Validation UI.

See Also

validationMessageMode

Specifies how the message about the validation rules that are not satisfied by this editor's value is displayed.

Type: String
Default Value: 'auto'
Accepted Values: 'auto' | 'always'

The following option values are possible:

  • auto
    The tooltip with the message is displayed when the editor is in focus.
  • always
    The tooltip with the message is not hidden when the editor loses focus.

When using the widget as an ASP.NET MVC Control, specify this option using the ValidationMessageMode enum. This enum accepts the following values: Auto and Always.

value

The currently selected value in the widget.

Type: any
Default Value: null

valueChangeEvent

Type: String
Default Value: 'change'

valueExpr

Specifies the name of a data source item field whose value is held in the value configuration option.

Type: String| function
Default Value: 'this'

If the options value is "this", the widget returns the entire selected object from the value option. Note that the "this" value is not supported by a widget bound to an ODataStore.

visible

Specifies whether the widget is visible.

Type: Boolean
Default Value: true

width

Specifies the width of the widget.

Type: Number|String| function
Return Value: Number|String
The width of the widget.
Default Value: undefined

This option accepts a value of one of the following types.

  • Number
    The width of the widget in pixels.

  • String
    A CSS-accepted measurement of width. For example, "55px", "80%", "auto", "inherit".

  • Function
    A function returning either of the above. For example:

    JavaScript
    width: function() {
        return window.innerWidth / 1.5;
    }