Configuration

See Also

• Configure a UI Component: Angular | Vue | React | jQuery | AngularJS | Knockout

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

This property is used when the UI component is displayed on a platform whose guidelines include the active state change for UI components.

Setting this property makes sense only when the height property is not specified.

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", "80%", "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
• validationErrors

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", "80%", "inherit".

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.

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", "80%", "inherit".

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

See Also

• Get a UI component Instance in Angular | AngularJS | Knockout | Vue | React

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

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

<dx-text-area ...
    (onOptionChanged)="handlePropertyChange($event)"> 
</dx-text-area>

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 { DxTextAreaModule } from 'devextreme-angular'; 

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

export class AppModule { }  

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

<script>  
import 'devextreme/dist/css/dx.light.css'; 
import DxTextArea from 'devextreme-vue/text-area'; 

export default { 
    components: { 
        DxTextArea
    }, 
    // ...
    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 TextArea from 'devextreme-react/text-area'; 

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

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

See Also

• valueChangeEvent

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

  Angular

  app.component.html

  app.component.ts

  app.module.ts

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

  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 { DxTextAreaModule } from 'devextreme-angular';
  
  @NgModule({
      declarations: [
          AppComponent
      ],
      imports: [
          BrowserModule,
          DxTextAreaModule
      ],
      providers: [ ],
      bootstrap: [AppComponent]
  })
  export class AppModule { }

  Vue

  App.vue

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

  React

  App.js

  import React from 'react';
  
  import 'devextreme/dist/css/dx.light.css';
  
  import TextArea, {
      Button as TextAreaButton
  } from 'devextreme-react/text-area';
  
  class App extends React.Component {
      myCustomButtonConfig = {
          onClick: (e) => {
              // ...
          },
          disabled: false
      };
      render() {
          return (
              <TextArea>
                  <TextAreaButton
                      name="myCustomButton"
                      location="after"
                      options={this.myCustomButtonConfig}
                  />
              </TextArea>
          );
      }
  }
  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() {
      $("#textAreaContainer").dxTextArea({
          // ...
          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-text-area ...
      (onOptionChanged)="changeButtonState">
      <dxi-button
          name="myCustomButton"
          ...
      ></dxi-button>
  </dx-text-area>

  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 { DxTextAreaModule } from 'devextreme-angular';
  
  @NgModule({
      declarations: [
          AppComponent
      ],
      imports: [
          BrowserModule,
          DxTextAreaModule
      ],
      providers: [ ],
      bootstrap: [AppComponent]
  })
  export class AppModule { }

  Vue

  App.vue

  <template>
      <DxTextArea ...
          @option-changed="changeButtonState">
          <DxTextAreaButton
              name="myCustomButton"
              ...
          />
      </DxTextArea>
  </template>
  
  <script>
  import 'devextreme/dist/css/dx.light.css';
  
  import DxTextArea, {
      DxButton as DxTextAreaButton
  } from 'devextreme-vue/text-area';
  
  export default {
      components: {
          DxTextArea,
          DxTextAreaButton
      },
      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 TextArea, {
      Button as TextAreaButton
  } from 'devextreme-react/text-area';
  
  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 (
              <TextArea ...
                  onOptionChanged={this.changeButtonState}>
                  <TextAreaButton
                      name="myCustomButton"
                      ...
                  />
              </TextArea>
          );
      }
  }
  export default App;

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

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.

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.

The following table illustrates the validation status indicators:

validationStatus	Indicator
"pending"
"valid"
"invalid"

View Demo

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

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", "80%", "auto", "inherit".

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

  JavaScript

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