Configuration

An object defining configuration options for the widget.

cols[]

Specifies the collection of columns for the grid used to position layout elements.

Type: Array
Show Example:
AngularJS
Knockout
jQuery

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.

To display widget items, a default template can be used. This template is based on the data source fields that are listed in the Default Item Template section of the widget's API.

disabled

A Boolean value specifying whether or not the widget can respond to user interaction.

Type: Boolean
Default Value: false

Create an observable variable and assign it to this option to specify the availability of the widget at runtime.

elementAttr

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

Type: Object
Default Value: {}

When you configure this option using a server-side wrapper, 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" }
    })
)

height

Specifies the height of the widget.

Return Value: Number|String

The widget height.

Default Value: '100%'

The option can hold a value of the following types.

  • number
    The height of the widget in pixels

  • string
    A CSS measurement of the widget height (e.g., "55px", "80%", "auto" and "inherit")

  • function
    A function returning the widget height, e.g.,

    JavaScript
    height: function () {
        return baseHeight - 10 + "%";
    }

hoverStateEnabled

A Boolean value specifying whether or not the widget changes its state when being hovered by an end user.

Type: Boolean
Default Value: false

itemHoldTimeout

The time period in milliseconds before the onItemHold event is raised.

Type: Number
Default Value: 750

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.

To display widget items, a default template can be used. This template is based on the data source fields that are listed in the Default Item Template section of the widget's API.

itemTemplate

The template to be used for rendering items.

Type: template
Function parameters:
itemData: Object

The item object to be rendered.

itemIndex: Number

The index of the item to be rendered.

itemElement: jQuery

An HTML element of the item to be rendered.

Return Value: String|DOM Node|jQuery

A template name or a template container.

Default Value: 'item'

A binding context of an item template is the data source object that corresponds to the currently rendered item.

In Knockout approach, you can bind template elements to the item object's fields directly. To access another binding context within an item template, use Knockout binding variables.

In AngularJS Approach, if you need to access item object's fields within a template, use a variable whose name is assigned to the dx-item-alias directive. Add the directive to the widget element to specify an alias to the root object of an item. Without this directive, item object fields are beyond reach. To access another binding context within an item template, use AngularJS binding variables.

See Also

onContentReady

A handler for the contentReady event. Executed when the widget's content is ready. This handler may be executed multiple times during the widget's lifetime depending on the number of times its content changes.

Type: function
Function parameters:

Information about the event.

Object structure:
component: Object

The widget's instance.

element: jQuery

The widget's container.

model: Object

The model data. Available only when using Knockout.

Default Value: null

onDisposing

A handler for the disposing 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 widget is being removed.

NOTE
The function assigned to this option is executed only if the widget is removed using the remove(), empty(), or html() jQuery methods.

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.

onItemClick

A handler for the itemClick event.

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.

itemData: Object

The data that is bound to the clicked item.

itemElement: jQuery

An HTML element of the item.

itemIndex: Number

Specifies the index of the clicked item.

jQueryEvent: jQuery.Event

Specifies the jQuery event that caused action execution.

Default Value: null

Assign a function to perform a custom action when a widget item is clicked.

To navigate to a specific URL when the itemClick event fires, assign that URL or the anchor part (#) of that URL directly to this option as a string.

onItemContextMenu

A handler for the itemContextMenu 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.

itemData: Object

The data that is bound to the item.

itemElement: jQuery

An HTML element of the item.

itemIndex: Number

Specifies the index of the item.

jQueryEvent: jQuery.Event

Specifies the jQuery event that caused action execution.

Default Value: null

Assign a function to perform a custom action when the right mouse button is clicked when the pointer is over a widget item, or when the "sustained" (also known as a long press) touch action is performed.

onItemHold

A handler for the itemHold 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.

itemData: Object

The data that is bound to the item being held.

itemElement: jQuery

An HTML element of the item.

itemIndex: Number

Specifies the index of the item being held.

Default Value: null

Assign a function to perform a custom action when the widget's collection item is being held for a specified time period (see the itemHoldTimeout option).

onItemRendered

A handler for the itemRendered 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 available for binding against the element. Available only in the Knockout approach.

itemData: Object

The data that is bound to the item to be rendered.

itemElement: jQuery

An HTML element of the item.

itemIndex: Number

Specifies the index of the rendered item.

Default Value: null

Assign a function to perform a custom action after a collection item is rendered.

onOptionChanged

A handler for the optionChanged event.

Type: function
Function parameters:

Provides function parameters.

Object structure:
component: Object

Provides access to the widget instance.

name: String

Specifies the name of the option whose value is changed.

fullName: String

Specifies a full name of the option whose value is changed. The full name is formed by concatenating the names of the options that are presented in the hierarchy of the given option. The names are delimited by commas.

value: any

Specifies a new value for the option.

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 an option of the component is changed.

rows[]

Specifies the collection of rows for the grid used to position layout elements.

Type: Array
Show Example:
AngularJS
Knockout
jQuery

rtlEnabled

Specifies whether or not the current component supports a right-to-left representation.

Type: Boolean
Default Value: false

If you need to switch the display of this DevExtreme component to right-to-left, enable a specifically designed configuration option - rtlEnabled. When this option is set to true, the text flows from right to left, and the layout the component's elements is reversed. To switch the entire application/site to a right-to-left representation, use the static DevExpress.rtlEnabled field.

screenByWidth

Specifies the function returning the size qualifier depending on the screen's width.

Type: function
Default Value: null

The function passed to this option accepts the screen's width as a parameter and should return a string containing the needed size qualifier.

JavaScript
var responsiveBoxOptions: {
    screenByWidth: function(width) {
        if( width < 768 )
            return 'xs';
        if( width < 992 )
            return 'sm';
        if( width < 1200 )
            return 'md';
        return 'lg';
    }
}

singleColumnScreen

Decides on which screens all layout elements should be arranged in a single column.

Type: String
Default Value: ''

This option accepts a single or several size qualifiers separated by a space.

visible

A Boolean value specifying whether or not the widget is visible.

Type: Boolean
Default Value: true

width

Specifies the width of the widget.

Return Value: Number|String

The widget width.

Default Value: '100%'

The option can hold a value of the following types.

  • numeric
    The widget width in pixels.
  • string
    A CSS measurement of the widget width (e.g., "55px", "80%", "auto" and "inherit").
  • function
    The function returning the widget width. For example, see the following code.

    JavaScript
    width: function () { 
        return baseWidth - 10 + "%";
    }