JavaScript/jQuery TextBox - Handle the Keyboard Events
The TextBox raises four keyboard events: keyDown, keyPress, keyUp and enterKey. Within the functions that handle them, you can access the original keyboard events. If you are not going to change the functions during the lifetime of the UI component, assign them to the respective UI component properties.
jQuery
$(function() { $("#textBoxContainer").dxTextBox({ onKeyDown: function (e) { const keyCode = e.event.key; // Event handling commands go here }, onKeyPress: function (e) { const keyCode = e.event.key; // Event handling commands go here }, onKeyUp: function (e) { const keyCode = e.event.key; // Event handling commands go here }, onEnterKey: function (e) { // Event handling commands go here } }); });
Angular
<dx-text-box (onKeyDown)="onKeyDown($event)" (onKeyPress)="onKeyPress($event)" (onKeyUp)="onKeyUp($event)" (onEnterKey)="onEnterKey($event)"> </dx-text-box>
import { DxTextBoxModule } from "devextreme-angular"; // ... export class AppComponent { onKeyDown (e) { let keyCode = e.event.key; // Event handling commands go here } onKeyPress (e) { let keyCode = e.event.key; // Event handling commands go here } onKeyUp (e) { let keyCode = e.event.key; // Event handling commands go here } onEnterKey (e) { // Event handling commands go here } } @NgModule({ imports: [ // ... DxTextBoxModule ], // ... })
Vue
<template> <DxTextBox @key-down="onKeyDown" @key-press="onKeyPress" @key-up="onKeyUp" @enter-key="onEnterKey" /> </template> <script> import 'devextreme/dist/css/dx.common.css'; import 'devextreme/dist/css/dx.light.css'; import { DxTextBox } from 'devextreme-vue/text-box'; export default { components: { DxTextBox }, methods: { onKeyDown(e) { const keyCode = e.event.key; // Event handling commands go here }, onKeyPress(e) { const keyCode = e.event.key; // Event handling commands go here }, onKeyUp(e) { const keyCode = e.event.key; // Event handling commands go here }, onEnterKey(e) { // Event handling commands go here } } } </script>
React
import React from 'react'; import 'devextreme/dist/css/dx.common.css'; import 'devextreme/dist/css/dx.light.css'; import { TextBox } from 'devextreme-react/text-box'; class App extends React.Component { render() { return ( <TextBox onKeyDown={this.onKeyDown} onKeyPress={this.onKeyPress} onKeyUp={this.onKeyUp} onEnterKey={this.onEnterKey} /> ); } onKeyDown(e) { let keyCode = e.event.key; // Event handling commands go here } onKeyPress(e) { let keyCode = e.event.key; // Event handling commands go here } onKeyUp(e) { let keyCode = e.event.key; // Event handling commands go here } onEnterKey(e) { // Event handling commands go here } } export default App;
If you are going to change the handling functions at runtime, or if you need to attach several functions to a single event, use the on(eventName, eventHandler) method. This approach is more typical of jQuery.
const keyDownHandler1 = function (e) { const keyCode = e.event.key; // First handler of the "keyDown" event }; const keyDownHandler2 = function (e) { const keyCode = e.event.key; // Second handler of the "keyDown" event }; $("#textBoxContainer").dxTextBox("instance") .on("keyDown", keyDownHandler1) .on("keyDown", keyDownHandler2);
You can implement a custom handler for a key using the registerKeyHandler(key, handler) method.
jQuery
function registerKeyHandlers () { const textBox = $("#textBoxContainer").dxTextBox("instance"); textBox.registerKeyHandler("backspace", function(e) { // The argument "e" contains information on the event }); textBox.registerKeyHandler("space", function(e) { // ... }); }
Angular
import { ..., ViewChild, AfterViewInit } from '@angular/core'; import { DxTextBoxModule, DxTextBoxComponent } from 'devextreme-angular'; // ... export class AppComponent implements AfterViewInit { @ViewChild(DxTextBoxComponent, { static: false }) textBox: DxTextBoxComponent; // Prior to Angular 8 // @ViewChild(DxTextBoxComponent) textBox: DxTextBoxComponent; ngAfterViewInit () { this.textBox.instance.registerKeyHandler('backspace', function(e) { // The argument "e" contains information on the event }); this.textBox.instance.registerKeyHandler('space', function(e) { // ... }); } } @NgModule({ imports: [ // ... DxTextBoxModule ], // ... })
Vue
<template> <DxTextBox :ref="myTextBoxRef" /> </template> <script> import 'devextreme/dist/css/dx.common.css'; import 'devextreme/dist/css/dx.light.css'; import DxTextBox from 'devextreme-vue/text-box'; const myTextBoxRef = 'my-text-box'; export default { components: { DxTextBox }, data() { return { myTextBoxRef } }, computed: { textBox: function() { return this.$refs[myTextBoxRef].instance; } }, mounted: function() { this.textBox.registerKeyHandler('backspace', function(e) { // The argument "e" contains information on the event }); this.textBox.registerKeyHandler('space', function(e) { // ... }); } } </script>
React
import React from 'react'; import 'devextreme/dist/css/dx.common.css'; import 'devextreme/dist/css/dx.light.css'; import { TextBox } from 'devextreme-react/text-box'; class App extends React.Component { constructor(props) { super(props); this.textBoxRef = React.createRef(); } render() { return ( <TextBox ref={this.textBoxRef} /> ); } get textBox() { return this.textBoxRef.current.instance; } componentDidMount() { this.textBox.registerKeyHandler('backspace', function(e) { // The argument "e" contains information on the event }); this.textBox.registerKeyHandler('space', function(e) { // ... }); } } export default App;
See Also
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