Angular SelectBox Properties

View on GitHub

See Also

View Demo

See Also

• Create a User-Defined Item

The value of this property will be passed to the accesskey attribute of the HTML element that underlies the UI component.

The UI component switches to the active state when users press down the primary mouse button. When this property is set to true, the CSS rules for the active state apply. You can change these rules to customize the component.

Use this property when you display the component on a platform whose guidelines include the active state change for UI components.

Built-in buttons should also be declared in this array. You can find an example in the following demo:

View Demo

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

The recommended events are "blur", "change", and "focusout", but you can use other events as well. The default value of this property is "change", and items are created when the component loses focus.

If you want to enable custom item creation when users press the Tab key, assign "change" or "focusout" to this property.

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

Depending on your data source, bind the SelectBox to data as follows. In each case, also specify the valueExpr, displayExpr, or both if the data source provides objects.

• Data Array
  Assign the array to the dataSource option.

• Read-Only Data in JSON Format
  Set the dataSource property 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 UI components 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";
      $("#selectBoxContainer").dxSelectBox({
          // ...
          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-select-box ...
      [dataSource]="store">
  </dx-select-box>

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

  Vue

  App.vue

  <template> 
      <DxSelectBox ...
          :data-source="store" />
  </template>
  
  <script>
  import 'devextreme/dist/css/dx.light.css';
  
  import CustomStore from 'devextreme/data/custom_store';
  import { createStore } from 'devextreme-aspnet-data-nojquery';
  import { DxSelectBox } from 'devextreme-vue/select-box';
  
  export default {
      components: {
          DxSelectBox
      },
      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.light.css';
  
  import CustomStore from 'devextreme/data/custom_store';
  import { createStore } from 'devextreme-aspnet-data-nojquery';
  import SelectBox from 'devextreme-react/select-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 (
              <SelectBox ...
                  dataSource={store} />
          );
      }
  }
  export default App;

• Any other data source
  Implement a CustomStore.

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

View Demo

View Demo

View Demo

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

displayExpr: "name"

... or to a function that returns the displayed value:

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

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

See Also

• valueExpr

The value you pass to this property does not affect UI component behavior. Pass an observable variable to this property to get the value currently displayed by the UI component.

View Demo

See Also

• Custom Templates

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

If you define a fieldTemplate, the component does not render the underlying HTML. In this case, you should render hidden input with the corresponding name attribute to submit values through a HTML form.

The example below shows how to define the fieldTemplate. If you want to customize the field's text, use the TextBox's value property.

$(function() {
    $("#selectBox").dxSelectBox({
        // ...
        fieldTemplate(data, container) {
            container.append(
                $('<div>').dxTextBox({
                    value: data.Category + ": " + data.Name,
                    readOnly: true
                })
            )
        },
    });
});

<dx-select-box ...
    fieldTemplate="field"
>
    <div *dxTemplate="let data of 'field'">
        <div>
            <dx-text-box 
                [value]="data && data.Category + ': ' + data.Name" 
                [readOnly]="true"
            >
            </dx-text-box>
        </div>
    </div>
</dx-select-box>

<template>
    <DxSelectBox ...
        field-template="field"
    >
        <template #field="{ data }">
            <DxTextBox 
                :value="data && data.Category + ': ' + data.Name" 
                :read-only="true"
            />
        </template>
    </DxSelectBox>
</template>

<script>
// ...
import DxSelectBox from 'devextreme-vue/select-box';
import DxTextBox from 'devextreme-vue/text-box';

export default {
    components: {
        DxSelectBox,
        DxTextBox
    },
    data() {
        return {
            // ...
        }
    }
}
</script>

import React from "react";
import SelectBox from "devextreme-react/select-box";
import TextBox from "devextreme-react/text-box";

function Field(data) {
    return <TextBox value={data && data.Category + ': ' + data.Name} readOnly={true} />;
}
function App() {
    return (
        <SelectBox ...
            fieldRender={Field}
        />
        </div>
    );
}

export default App;

View Demo

See Also

• Customize Item Appearance
• Custom Templates

When this property is true, make sure that all data source objects have the following structure:

const dataSource = [{
    key: "Group 1", // Group caption 
    items: [ // Items in the group
        { ... },
        { ... }
    ]
}, {
    // ...
}];

You can supply data to this structure using the DataSource object's group property.

SelectBox Demo TagBox Demo

See Also

• SelectBox - Grouping
• TagBox - Grouping

View Demo

See Also

• Customize Group Headers
• Custom Templates

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

• Number
  The height in pixels.

• String
  A CSS-accepted measurement of height. For example, "55px", "20vh", "80%", "inherit".

• Function (deprecated since v21.2)
  Refer to the W0017 warning description for information on how you can migrate to viewport units.

$(function(){
    $("#selectBoxContainer").dxSelectBox({
        // ...
        inputAttr: {
            id: "inputId"
        }
    });
});

<dx-select-box ...
    [inputAttr]="{ id: 'inputId' }">
</dx-select-box>

import { DxSelectBoxModule } from "devextreme-angular";
// ...
export class AppComponent {
    // ...
}
@NgModule({
    imports: [
        // ...
        DxSelectBoxModule
    ],
    // ...
})

<template>
    <DxSelectBox
        :input-attr="inputAttr"
    />
</template>

<script>
import 'devextreme/dist/css/dx.light.css';

import DxSelectBox from 'devextreme-vue/select-box';

export default {
    components: {
        DxSelectBox
    },
    data() {
        return {
            inputAttr: { id: 'inputId' }
        }
    }
}
</script>

import 'devextreme/dist/css/dx.light.css';

import SelectBox from 'devextreme-react/select-box';

const inputAttr = { id: 'inputId' };

export default function App() {
    return (
        <SelectBox
            inputAttr={inputAttr}
        />
    );
}

@(Html.DevExtreme().SelectBox()
    .InputAttr("id", "inputId")
    // ===== or =====
    .InputAttr(new {
        @id = "inputId"
    })
    // ===== or =====
    .InputAttr(new Dictionary<string, object>() {
        { "id", "inputId" }
    })
)

@(Html.DevExtreme().SelectBox() _
    .InputAttr("id", "inputId")
    ' ===== or =====
    .InputAttr(New With {
        .id = "inputId"
    })
    ' ===== or =====
    .InputAttr(New Dictionary(Of String, Object) From {
        { "id", "inputId" }
    })
)

To improve accessibility, use this property to specify aria-label for the component.

$(function(){
    $("#selectBoxContainer").dxSelectBox({
        // ...
        inputAttr: {
            'aria-label': 'your-label',
        },
    });
});

<dx-select-box ...
    [inputAttr]="{ 'aria-label': 'your-label' }">
</dx-select-box>

<template>
    <DxSelectBox
        :input-attr="inputAttr"
    />
</template>

<script>
import DxSelectBox from 'devextreme-vue/select-box';

export default {
    components: {
        DxSelectBox
    },
    data() {
        return {
            inputAttr: { 'aria-label': 'your-label' }
        }
    }
}
</script>

import SelectBox from 'devextreme-react/select-box';

const inputAttr = { 'aria-label': 'your-label' };

export default function App() {
    return (
        <SelectBox
            inputAttr={inputAttr}
        />
    );
}

You do not need to specify aria-label if you use label.

This property is a read-only flag. You can use it to check if the editor value changed.

$(() => {
    const selectBox = $('#selectBox').dxSelectBox({
        // ...
    }).dxSelectBox('instance');

    $('#button').dxButton({
        // ...
        onClick () {
            if (selectBox.option('isDirty')) {
                DevExpress.ui.notify("Do not forget to save changes", "warning", 500);
            }
        }
    });
});

import { Component, ViewChild } from '@angular/core';
import { DxSelectBoxComponent, DxButtonModule } from 'devextreme-angular';
import notify from 'devextreme/ui/notify';

@Component({
    selector: 'app-root',
    templateUrl: './app.component.html',
    styleUrls: ['./app.component.css']
})
export class AppComponent {
    @ViewChild('selectBoxRef', { static: false }) selectBox: DxSelectBoxComponent;

    onClick () {
        if (this.selectBox.instance.option('isDirty')) {
            notify("Do not forget to save changes", "warning", 500);
        }
    }
}

<dx-select-box ... 
    #selectBoxRef
>
</dx-select-box>
<dx-button ...
    (onClick)="onClick($event)"
>
</dx-button>

<template>
    <DxSelectBox ...
        :ref="selectBoxRef"
    >
    </DxSelectBox>
    <DxButton ...
        @click="onClick"
    />
</template>

<script>
import 'devextreme/dist/css/dx.light.css';
import DxSelectBox from 'devextreme-vue/select-box';
import DxButton from 'devextreme-vue/button';
import notify from 'devextreme/ui/notify';

export default {
    components: {
        DxSelectBox,
        DxButton
    },

    data() {
        return {
            selectBoxRef
        }
    },

    methods: {
        onClick () {
            if (this.selectBox.option('isDirty')) {
                notify("Do not forget to save changes", "warning", 500);
            }
        }
    },

    computed: {
        selectBox: function() {
            return this.$refs[selectBoxRef].instance;
        }
    }
}
</script>

import React, { useRef } from 'react';
import SelectBox from 'devextreme-react/select-box';
import Button from 'devextreme-react/button';
import 'devextreme/dist/css/dx.light.css';

const App = () => {
    const selectBoxRef = useRef(null);

    const onClick = () => {
        if (this.selectBoxRef.current.instance.option('isDirty')) {
            notify("Do not forget to save changes", "warning", 500);
        }
    };

    return (
        <SelectBox ...
            ref={selectBoxRef}
        >
        </SelectBox>
        <Button ...
            onClick={onClick}
        />
    );
};

export default App;

See Also

• reset

See Also

• validationErrors

The items array can contain:

• Objects with fields described in this section
• Objects with any other fields. In this case, specify the itemTemplate.

If you need to update the UI component items, reassign the entire items array as shown in the following example:

selectBoxInstance.option('items', newItems);

As an alternative to items, you can use the dataSource property. It accepts the DataSource object, whose underlying stores provide an API that allows you to update individual items without reassigning the entire item collection.

View Demo

View Demo

See Also

• Customize Item Appearance
• Custom Templates

See Also

• labelMode
• placeholder

This property can have one of the following values:

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

View Demo

See Also

• showDataBeforeSearch

Specify this property if the UI component lies within an HTML form that will be submitted.

The SelectBox component evaluates the noDataText property's value. This evaluation, however, makes the SelectBox potentially vulnerable to XSS attacks. To guard against these attacks, encode the HTML markup before you assign it to the noDataText property. Refer to the following help topic for more information: Potentially Vulnerable API - noDataText.

View Demo

You can specify DOM events after which the component calls this function. Use the customItemCreateEvent property for this purpose. Besides the event passed to this property, the item can also be created when users press the Enter key.

The following code shows how to enable item creation when the Space key is pressed:

$(function() {
    $("#selectBox").dxSelectBox({
        // ...
        items: [{ id: 1, text: 'item 1'}],
        acceptCustomValue: true,
        displayExpr: 'text',
        onCustomItemCreating: (args) => {
            if (!args.text) {
                args.customItem = null;
                return;
            }

            const { component, text } = args;
            const currentItems = component.option('items');

            const newId = currentItems.at(-1).id + 1;
            const newItem = {
                id: newId,
                text: text.trim(),
            };

            const itemInDataSource = currentItems.find((item) => item.text === newItem.text)
            if (itemInDataSource) {
                args.customItem = itemInDataSource;
            } else {    
                currentItems.push(newItem);
                component.option('items', currentItems);
                args.customItem = newItem;
            }
        },
        onKeyDown: (e) => {
            if (e.event.code === 'Space') {
                const event = new KeyboardEvent('keydown', {
                    key: 'Enter',
                    keyCode: 13,
                    which: 13,
                });
                const target = e.event.target;
                target.dispatchEvent(event);
            }
        }
    });
});

<dx-select-box ...
    [items]="itemsArray"
    displayExpr="text"
    [acceptCustomValue]="true"
    (onCustomItemCreating)="onCustomItemCreating($event)"
    (onKeyDown)="onKeyDown($event)"
>
</dx-select-box>

// ...
export class AppComponent {
    itemsArray = [{ id: 1, text: 'item 1'}];

    onCustomItemCreating(args) {
        if (!args.text) {
            args.customItem = null;
            return;
        }

        const { component, text } = args;
        const currentItems = component.option('items');

        const newId = currentItems.at(-1).id + 1;
        const newItem = {
            id: newId,
            text: text.trim(),
        };

        const itemInDataSource = currentItems.find((item) => item.text === newItem.text)
        if (itemInDataSource) {
            args.customItem = itemInDataSource;
        } else {    
            currentItems.push(newItem);
            component.option('items', currentItems);
            args.customItem = newItem;
        }
    }
    onKeyDown(e) {
        if (e.event.code === 'Space') {
            const event = new KeyboardEvent('keydown', {
                key: 'Enter',
                keyCode: 13,
                which: 13,
            });
            const target = e.event.target;
            target.dispatchEvent(event);
        }
    }
}

<template>
    <DxSelectBox ...
        :items="itemsArray"
        display-expr="text"
        :accept-custom-value="true"
        @customItemCreating="onCustomItemCreating"
        @keyDown="onKeyDown"
    >
    </DxSelectBox>
</template>

<script>
// ...
export default {
    components: {
        DxSelectBox
    },
    data() {
        return {
            itemsArray: [{ id: 1, text: 'item 1'}]
        }
    },
    methods: {
        onCustomItemCreating(args) {
            if (!args.text) {
                args.customItem = null;
                return;
            }

            const { component, text } = args;
            const currentItems = component.option('items');

            const newId = currentItems.at(-1).id + 1;
            const newItem = {
                id: newId,
                text: text.trim(),
            };

            const itemInDataSource = currentItems.find((item) => item.text === newItem.text)
            if (itemInDataSource) {
                args.customItem = itemInDataSource;
            } else {    
                currentItems.push(newItem);
                component.option('items', currentItems);
                args.customItem = newItem;
            }
        },
        onKeyDown(e) {
            if (e.event.code === 'Space') {
                const event = new KeyboardEvent('keydown', {
                    key: 'Enter',
                    keyCode: 13,
                    which: 13,
                });
                const target = e.event.target;
                target.dispatchEvent(event);
            }
        }
    }
}
</script>

// ...
const itemsArray = [{ id: 1, text: 'item 1'}];

const onCustomItemCreating = (args) => {
    if (!args.text) {
        args.customItem = null;
        return;
    }

    const { component, text } = args;
    const currentItems = component.option('items');

    const newId = currentItems.at(-1).id + 1;
    const newItem = {
        id: newId,
        text: text.trim(),
    };

    const itemInDataSource = currentItems.find((item) => item.text === newItem.text)
    if (itemInDataSource) {
        args.customItem = itemInDataSource;
    } else {    
        currentItems.push(newItem);
        component.option('items', currentItems);
        args.customItem = newItem;
    }
}

const onKeyDown = (e) => {
    if (e.event.code === 'Space') {
        const event = new KeyboardEvent('keydown', {
            key: 'Enter',
            keyCode: 13,
            which: 13,
        });
        const target = e.event.target;
        target.dispatchEvent(event);
    }
}

function App() {
    return (
        <SelectBox ...
            items={itemsArray}
            displayExpr="text"
            acceptCustomValue={true}
            onCustomItemCreating={onCustomItemCreating}
            onKeyDown={onKeyDown}
        />
    );
}

export default App;

See Also

• Create a User-Defined Item

<dx-select-box ...
    (onInitialized)="saveInstance($event)">
</dx-select-box>

import { Component } from "@angular/core";
import SelectBox from "devextreme/ui/data_grid";
// ...
export class AppComponent {
    selectBoxInstance: SelectBox;
    saveInstance (e) {
        this.selectBoxInstance = e.component;
    }
}

<template>
    <div>
        <DxSelectBox ...
            @initialized="saveInstance">
        </DxSelectBox>
    </div>
</template>

<script>
import DxSelectBox from 'devextreme-vue/select-box';

export default {
    components: {
        DxSelectBox
    },
    data: function() {
        return {
            selectBoxInstance: null
        };
    },
    methods: {
        saveInstance: function(e) {
            this.selectBoxInstance = e.component;
        }
    }
};
</script>

<template>
    <div>
        <DxSelectBox ...
            @initialized="saveInstance">
        </DxSelectBox>
    </div>
</template>

<script setup>
import DxSelectBox from 'devextreme-vue/select-box';

let selectBoxInstance = null;

const saveInstance = (e) => {
    selectBoxInstance = e.component;
}
</script>

import SelectBox from 'devextreme-react/select-box';

class App extends React.Component {
    constructor(props) {
        super(props);

        this.saveInstance = this.saveInstance.bind(this);
    }

    saveInstance(e) {
        this.selectBoxInstance = e.component;
    }

    render() {
        return (
            <div>
                <SelectBox onInitialized={this.saveInstance} />
            </div>
        );
    }
}

See Also

The following example shows how to subscribe to component property changes:

$(function() {
    $("#selectBoxContainer").dxSelectBox({
        // ...
        onOptionChanged: function(e) {
            if(e.name === "changedProperty") {
                // handle the property change here
            }
        }
    });
});

<dx-select-box ...
    (onOptionChanged)="handlePropertyChange($event)"> 
</dx-select-box>

import { Component } from '@angular/core'; 

@Component({ 
    selector: 'app-root', 
    templateUrl: './app.component.html', 
    styleUrls: ['./app.component.css'] 
}) 

export class AppComponent { 
    // ...
    handlePropertyChange(e) {
        if(e.name === "changedProperty") { 
            // handle the property change here
        }
    }
}

import { BrowserModule } from '@angular/platform-browser'; 
import { NgModule } from '@angular/core'; 
import { AppComponent } from './app.component'; 
import { DxSelectBoxModule } from 'devextreme-angular'; 

@NgModule({ 
    declarations: [ 
        AppComponent 
    ], 
    imports: [ 
        BrowserModule, 
        DxSelectBoxModule 
    ], 
    providers: [ ], 
    bootstrap: [AppComponent] 
}) 

export class AppModule { }  

<template> 
    <DxSelectBox ...
        @option-changed="handlePropertyChange"
    />            
</template> 

<script>  
import 'devextreme/dist/css/dx.light.css'; 
import DxSelectBox from 'devextreme-vue/select-box'; 

export default { 
    components: { 
        DxSelectBox
    }, 
    // ...
    methods: { 
        handlePropertyChange: function(e) {
            if(e.name === "changedProperty") {
                // handle the property change here
            }
        }
    } 
} 
</script> 

import React from 'react';  
import 'devextreme/dist/css/dx.light.css'; 

import SelectBox from 'devextreme-react/select-box'; 

const handlePropertyChange = (e) => {
    if(e.name === "changedProperty") {
        // handle the property change here
    }
}

export default function App() { 
    return ( 
        <SelectBox ...
            onOptionChanged={handlePropertyChange}
        />        
    ); 
} 

View on GitHub

See Also

• valueChangeEvent

See Also

• showDropDownButton

View Demo

When this property is set to true, the following applies:

• The editor's value cannot be changed using the UI.
• Built-in action buttons are invisible.

• Custom action buttons are visible but disabled. If a button should not be disabled, set its disabled property to false:

  jQuery

  index.js

  $(function() {
      $("#selectBoxContainer").dxSelectBox({
          // ...
          buttons: [{
              name: "myCustomButton",
              location: "after",
              options: {
                  onClick: function(e) {
                      // ...
                  },
                  disabled: false
              }
          }]
      });
  });

  Angular

  app.component.html

  app.component.ts

  app.module.ts

  <dx-select-box ... >
      <dxi-button
          name="myCustomButton"
          location="after"
          [options]="myCustomButtonConfig">
      </dxi-button>
  </dx-select-box>

  import { Component } from '@angular/core';
  
  @Component({
      selector: 'app-root',
      templateUrl: './app.component.html',
      styleUrls: ['./app.component.css']
  })
  export class AppComponent {
      myCustomButtonConfig = {
          onClick: (e) => {
              // ...
          },
          disabled: false
      };
  }

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

  Vue

  App.vue

  <template>
      <DxSelectBox ... >
          <DxSelectBoxButton
              name="myCustomButton"
              location="after"
              :options="myCustomButtonConfig"
          />
      </DxSelectBox>
  </template>
  
  <script>
  import 'devextreme/dist/css/dx.light.css';
  
  import DxSelectBox, {
      DxButton as DxSelectBoxButton
  } from 'devextreme-vue/select-box';
  
  export default {
      components: {
          DxSelectBox,
          DxSelectBoxButton
      },
      data() {
          return {
              myCustomButtonConfig: {
                  onClick: (e) => {
                      // ...
                  },
                  disabled: false
              }
          }
      }
  }
  </script>

  React

  App.js

  import React from 'react';
  
  import 'devextreme/dist/css/dx.light.css';
  
  import SelectBox, {
      Button as SelectBoxButton
  } from 'devextreme-react/select-box';
  
  class App extends React.Component {
      myCustomButtonConfig = {
          onClick: (e) => {
              // ...
          },
          disabled: false
      };
      render() {
          return (
              <SelectBox>
                  <SelectBoxButton
                      name="myCustomButton"
                      location="after"
                      options={this.myCustomButtonConfig}
                  />
              </SelectBox>
          );
      }
  }
  export default App;

  You can also hide a custom action button when the UI component becomes read-only. Set the button's visible property to false in the onOptionChanged function. To get the button, use the getButton(name) method:

  jQuery

  index.js

  $(function() {
      $("#selectBoxContainer").dxSelectBox({
          // ...
          buttons: [{
              name: "myCustomButton",
              // ...
          }],
          onOptionChanged: function(e) {
              if(e.name == "readOnly") {
                  const myButton = e.component.getButton("myCustomButton");
                  myButton.option("visible", !e.value); // Hide the button when readOnly: true
              }
          }
      });
  });

  Angular

  app.component.html

  app.component.ts

  app.module.ts

  <dx-select-box ...
      (onOptionChanged)="changeButtonState">
      <dxi-button
          name="myCustomButton"
          ...
      ></dxi-button>
  </dx-select-box>

  import { Component } from '@angular/core';
  
  @Component({
      selector: 'app-root',
      templateUrl: './app.component.html',
      styleUrls: ['./app.component.css']
  })
  export class AppComponent {
      changeButtonState(e) {
          if(e.name == 'readOnly') {
              let myButton = e.component.getButton('myCustomButton');
              myButton.option('visible', !e.value); // Hide the button when readOnly: true
          }
      }
  }

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

  Vue

  App.vue

  <template>
      <DxSelectBox ...
          @option-changed="changeButtonState">
          <DxSelectBoxButton
              name="myCustomButton"
              ...
          />
      </DxSelectBox>
  </template>
  
  <script>
  import 'devextreme/dist/css/dx.light.css';
  
  import DxSelectBox, {
      DxButton as DxSelectBoxButton
  } from 'devextreme-vue/select-box';
  
  export default {
      components: {
          DxSelectBox,
          DxSelectBoxButton
      },
      data() {
          return {
              // ...
          }
      },
      methods: {
          changeButtonState(e) {
              if(e.name == 'readOnly') {
                  let myButton = e.component.getButton('myCustomButton');
                  myButton.option('visible', !e.value); // Hide the button when readOnly: true
              }
          }
      }
  }
  </script>

  React

  App.js

  import React from 'react';
  
  import 'devextreme/dist/css/dx.light.css';
  
  import SelectBox, {
      Button as SelectBoxButton
  } from 'devextreme-react/select-box';
  
  class App extends React.Component {
      changeButtonState(e) {
          if(e.name == 'readOnly') {
              let myButton = e.component.getButton('myCustomButton');
              myButton.option('visible', !e.value); // Hide the button when readOnly: true
          }
      }
      render() {
          return (
              <SelectBox ...
                  onOptionChanged={this.changeButtonState}>
                  <SelectBoxButton
                      name="myCustomButton"
                      ...
                  />
              </SelectBox>
          );
      }
  }
  export default App;

View Demo

When this property is set to true, the UI component 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
});

DataGrid Demo Navigation UI Demo Editors Demo

View Demo

See Also

• Configure Search Parameters

In most cases, you should pass the name of a field by whose value data items are searched. If you need to search elements by several field values, assign an array of field names to this property.

searchExpr: ["firstName", "lastName"]

For more information on searching, refer to the Search API section of the Data Layer article. For information on getters, refer to the Getters and Setters section of the Data Layer article.

View Demo

View Demo

View Demo

The Clear button calls the reset method.

If this property is disabled, the UI component does not display values until the number of typed characters exceeds the minSearchLength value, otherwise it displays all values regardless of the specified filtering condition.

View Demo

See Also

• dropDownButtonTemplate

The following styles are available:

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 property will be passed to the tabindex attribute of the HTML element that underlies the UI component.

If the property is set to true, the text that items within the SelectBox contain is passed to the title attribute of the respective item.

See Also

• isValid

The following property 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.

If you set this property to auto, the component specifies the validation message position automatically.

The following example positions a validation message at the component's right:

$(function() {
    $("#selectBoxContainer").dxSelectBox({
        // ...
        validationMessagePosition: 'right'
    }).dxValidator({
        validationRules: [{
            type: 'required',
            message: 'Required',
        }],
    });
});

<dx-select-box ...
    validationMessagePosition="right">
    <dx-validator>
        <dxi-validation-rule
            type="required"
            message="Required"
        >
        </dxi-validation-rule>
    </dx-validator>
</dx-select-box>

<template>
    <DxSelectBox ...
        validation-message-position="right"
    >
        <DxValidator>
            <DxRequiredRule message="Required" />
        </DxValidator>
    </DxSelectBox>
</template>

<script>
    // ...
</script>

import React from 'react';
// ...

function App() {
    return (
        <SelectBox ...
            validationMessagePosition="right"
        >
            <Validator>
                <RequiredRule message="Required" />
            </Validator>
        </SelectBox>
    ); 

};
export default App;

The following table illustrates the validation status indicators:

validationStatus	Indicator
"pending"
"valid"
"invalid"

When you assign "invalid" to validationStatus, you can also use the validationErrors array to set an error message as shown below:

$(function() {
    const selectBox = $("#selectBoxContainer").dxSelectBox({
        // ...
    }).dxSelectBox("instance");

    function setInvalidStatus(message) {
        selectBox.option({
            validationStatus: "invalid",
            validationErrors: [{ message: message }]
        });
    }
});

<dx-select-box
    [validationStatus]="validationStatus"
    [validationErrors]="validationErrors">
</dx-select-box>

// ...
export class AppComponent {
    validationStatus: string = "valid";
    validationErrors: any;
    // ...
    setInvalidStatus(message) {
        this.validationStatus = "invalid";
        this.validationErrors = [{ message: message }];
    }
}

<template>
    <DxSelectBox ...
        :validation-status="validationStatus"
        :validation-errors="validationErrors"
    />
</template>

<script>
    // ...
    export default {
        // ...
        data() {
            return {
                validationStatus: "valid",
                validationErrors: []
            }
        },
        methods: {
            setInvalidStatus(message) {
                this.validationStatus = "invalid";
                this.validationErrors = [{ message: message }];
            }
        }
    }
</script>

import React, { useState } from 'react';
// ...

function App() {
    const [validationStatus, setValidationStatus] = useState("valid");
    const [validationErrors, setValidationErrors] = useState([]);

    const setInvalidStatus = message => {
        setValidationStatus("invalid");
        setValidationErrors([{ message: message }]);
    }

    return (
        <SelectBox
            validationStatus={validationStatus}
            validationErrors={validationErrors}
        />
    ); 

};
export default App;

When dataSource contains objects, you should define valueExpr to correctly identify data items. Otherwise, the component uses referential equality to compare objects. For example, when valueExpr is not specified and you assign an object with the same field and values as dataSource to the value property, these two objects are not equal, and the component displays nothing.

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

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

See Also

• onValueChanged

View Demo

When dataSource contains objects, you should define valueExpr to correctly identify data items. Otherwise, the component uses referential equality to compare objects, which may result in unexpected behavior.

If you use a store, the valueExpr property should have the same value as the key in the store. Alternatively, you can use this as a valueExpr but the key should be specified. Refer to the following article for more information: Troubleshooting - A Drop-Down Editor Does Not Show Data.

Do not use template as a valueExpr value.

See Also

• displayExpr

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

• Number
  The width in pixels.

• String
  A CSS-accepted measurement of width. For example, "55px", "20vw", "80%", "auto", "inherit".

• Function (deprecated since v21.2)
  Refer to the W0017 warning description for information on how you can migrate to viewport units.