JavaScript/jQuery DropDownBox Options

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

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

View Demo

See Also

• DropDownBox - Overview
• Custom Templates

If you use DevExtreme ASP.NET MVC Controls, refer to the Data Binding article.

The DropDownBox works with collections of objects or string, number, or boolean values.

Depending on your data source, bind the DropDownBox to data as follows. In each case, also specify the valueExpr and displayExpr options if the data source provides objects.

• Data Array
  Assign the array to the dataSource option.

• Read-Only Data in JSON Format
  Set the dataSource option to the URL of a JSON file or service that returns JSON data.

• OData
  Implement an ODataStore.

• Web API, PHP, MongoDB
  Use one of the following extensions to enable the server to process data according to the protocol DevExtreme widgets use:

  • DevExtreme.AspNet.Data
  • DevExtreme-PHP-Data
  • devextreme-query-mongodb

  Then, use the createStore method to configure access to the server on the client as shown below. This method is part of DevExtreme.AspNet.Data.

  jQuery

  JavaScript

  $(function() {
      let serviceUrl = "https://url/to/my/service";
      $("#dropDownBoxContainer").dxDropDownBox({
          // ...
          dataSource: DevExpress.data.AspNet.createStore({
              key: "ID",
              loadUrl: serviceUrl + "/GetAction",
              insertUrl: serviceUrl + "/InsertAction",
              updateUrl: serviceUrl + "/UpdateAction",
              deleteUrl: serviceUrl + "/DeleteAction"
          })
      })
  });

  Angular

  app.component.ts

  app.component.html

  app.module.ts

  import { Component } from '@angular/core';
  import CustomStore from 'devextreme/data/custom_store';
  import { createStore } from 'devextreme-aspnet-data-nojquery';
  
  @Component({
      selector: 'app-root',
      templateUrl: './app.component.html',
      styleUrls: ['./app.component.css']
  })
  export class AppComponent {
      store: CustomStore;
      constructor() {
          let serviceUrl = "https://url/to/my/service";
          this.store = createStore({
              key: "ID",
              loadUrl: serviceUrl + "/GetAction",
              insertUrl: serviceUrl + "/InsertAction",
              updateUrl: serviceUrl + "/UpdateAction",
              deleteUrl: serviceUrl + "/DeleteAction"
          })
      }
  }

  <dx-drop-down-box ...
      [dataSource]="store">
  </dx-drop-down-box>

  import { BrowserModule } from '@angular/platform-browser';
  import { NgModule } from '@angular/core';
  import { AppComponent } from './app.component';
  
  import { DxDropDownBoxModule } from 'devextreme-angular';
  
  @NgModule({
      declarations: [
          AppComponent
      ],
      imports: [
          BrowserModule,
          DxDropDownBoxModule
      ],
      providers: [],
      bootstrap: [AppComponent]
  })
  export class AppModule { }

  Vue

  App.vue

  <template> 
      <dx-drop-down-box ...
          :data-source="store" />
  </template>
  
  <script>
  import 'devextreme/dist/css/dx.common.css';
  import 'devextreme/dist/css/dx.light.css';
  
  import CustomStore from 'devextreme/data/custom_store';
  import { createStore } from 'devextreme-aspnet-data-nojquery';
  import { DxDropDownBox } from 'devextreme-vue/drop-down-box';
  
  export default {
      components: {
          DxDropDownBox
      },
      data() {
          const serviceUrl = "https://url/to/my/service";
          const store = createStore({
              key: "ID",
              loadUrl: serviceUrl + "/GetAction",
              insertUrl: serviceUrl + "/InsertAction",
              updateUrl: serviceUrl + "/UpdateAction",
              deleteUrl: serviceUrl + "/DeleteAction"
          });
          return {
              store
          }
      }
  }
  </script>

  React

  App.js

  import React from 'react';
  import 'devextreme/dist/css/dx.common.css';
  import 'devextreme/dist/css/dx.light.css';
  
  import CustomStore from 'devextreme/data/custom_store';
  import { createStore } from 'devextreme-aspnet-data-nojquery';
  import DropDownBox from 'devextreme-react/drop-down-box';
  
  const serviceUrl = "https://url/to/my/service";
  const store = createStore({
      key: "ID",
      loadUrl: serviceUrl + "/GetAction",
      insertUrl: serviceUrl + "/InsertAction",
      updateUrl: serviceUrl + "/UpdateAction",
      deleteUrl: serviceUrl + "/DeleteAction"
  });
  
  class App extends React.Component {
      render() {
          return (
              <DropDownBox ...
                  dataSource={store} />
          );
      }
  }
  export default App;

• Any other data source
  Implement a CustomStore.

Regardless of the data source on the input, the DropDownBox always wraps it in the DataSource object. This object allows you to sort, filter, group, and otherwise shape data. To get its instance, call the getDataSource() method.

If the element embedded in the DropDownBox widget is another DevExtreme widget, their data sources should be interrelated. Refer to the Synchronize with the Embedded Element article for more information.

Set this option to the name of a data field that provides displayed values...

displayExpr: "name"

... or to a function that combines the values of several data fields to create the displayed value:

displayExpr: function(item) {
    // "item" can be null
    return item && 'ID: ' + item.id + ', Name: ' + item.name;
}

Leave this option unspecified or set it to this if the data source contains primitives.

See Also

• valueExpr

See Also

• SelectBox - Customize Drop-Down Button Demo
• Custom Templates

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

In the following code, the fieldTemplate is used to stylize the text field with a custom CSS class:

$(function () {
    $("dropDownBoxContainer").dxDropDownBox({
        // ...
        fieldTemplate: function (value, fieldElement) {
            var result = $("<div class='custom-item'>");
            result
                .dxTextBox({
                    value: value,
                    readOnly: true 
                });
            fieldElement.append(result);
        }
    });
});

.custom-item {
    font-size: 16px;
}

<dx-drop-down-box ...
    fieldTemplate="field">
    <div *dxTemplate="let data of 'field'">
        <div class="custom-item">
            <dx-text-box 
                [value]="data" 
                [readOnly]="true"
            ></dx-text-box>
        </div>
    </div>
</dx-drop-down-box>

.custom-item {
    font-size: 16px;
}

<div dx-drop-down-box="{
    ...
    fieldTemplate: 'field'
}" dx-item-alias="data">
    <div data-options="dxTemplate: { name: 'field' }">
        <div class="custom-item">
            <div dx-text-box="{ value: data, readOnly: true }"></div>
        </div>
    </div>
</div>

.custom-item {
    font-size: 16px;
}

<div data-bind="dxDropDownBox: {
    ...
    fieldTemplate: 'field'
}">
    <div data-options="dxTemplate: { name: 'field' }">
        <div class="custom-item">
            <div data-bind="dxTextBox: { value: $data, readOnly: true }"></div>
        </div>
    </div>
</div>

.custom-item {
    font-size: 16px;
}

See Also

• Custom Templates

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

• Number
  The height 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;
  }

See Also

• Knockout Only - Validate a View Model
• Use a Custom Validation Engine

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.

If the number of entered characters reaches the value assigned to this option, the widget does not allow you to enter any more characters.

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.

See Also

• Get a Widget Instance in Angular | AngularJS | Knockout | Vue | React

See Also

• showDropDownButton

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.

DevExpress.config({
    rtlEnabled: true
});

See Also

• Right-to-Left Support Demo: DataGrid | Navigation Widgets | Editors

The Clear button sets the widget value to null.

See Also

• dropDownButtonTemplate

The following styles are available:

Use the EditorStylingMode enum to specify this option when the widget is used as an ASP.NET MVC Control. This enum accepts the following values: Outlined, Underlined, and Filled.

You can also use the global editorStylingMode setting to specify how the text fields of all editors in your application are styled.

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

See Also

• Use a Custom Validation Engine

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.

Use the ValidationMessageMode enum to specify this option when the widget is used as an ASP.NET MVC Control. This enum accepts the following values: Auto and Always.

This option accepts a single event name or several names separated by spaces.

The recommended events are "keyup", "blur", "change", and "focusout", but you can use other events as well.

Alternatively, you can specify the key in the store.

See Also

• displayExpr

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

• Number
  The width 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;
  }