DevExtreme jQuery/JS - Handle the Keyboard Events

The TextArea 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 widget, assign them to the respective widget options.

jQuery
JavaScript
$(function() {
    $("#textAreaContainer").dxTextArea({
        onKeyDown: function (e) {
            var keyCode = e.event.key;
            // Event handling commands go here
        },
        onKeyPress: function (e) {
            var keyCode = e.event.key;
            // Event handling commands go here
        },
        onKeyUp: function (e) {
            var keyCode = e.event.key;
            // Event handling commands go here
        },
        onEnterKey: function (e) {
            // Event handling commands go here
        }
    });
});
Angular
HTML
TypeScript
<dx-text-area
    (onKeyDown)="onKeyDown($event)"
    (onKeyPress)="onKeyPress($event)"
    (onKeyUp)="onKeyUp($event)"
    (onEnterKey)="onEnterKey($event)">
</dx-text-area>
import { DxTextAreaModule } 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: [
         // ...
         DxTextAreaModule
     ],
     // ...
 })

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.

JavaScript
var keyDownHandler1 = function (e) {
    var keyCode = e.event.key;
    // First handler of the "keyDown" event
};

var keyDownHandler2 = function (e) {
    var keyCode = e.event.key;
    // Second handler of the "keyDown" event
};

$("#textAreaContainer").dxTextArea("instance")
    .on("keyDown", keyDownHandler1)
    .on("keyDown", keyDownHandler2);

You can also implement handlers for other keys using the registerKeyHandler(key, handler) method.

jQuery
JavaScript
function registerKeyHandlers () {
    let textArea =  $("#textAreaContainer").dxTextArea("instance");
    textArea.registerKeyHandler("backspace", function (e) {
        // The argument "e" contains information on the event
    });
    textArea.registerKeyHandler("space", function (e) {
        // ...
    });
}
Angular
TypeScript
import { ..., ViewChild, AfterViewInit } from "@angular/core";
import { DxTextAreaModule, DxTextAreaComponent } from "devextreme-angular";
// ...
export class AppComponent implements AfterViewInit {
    @ViewChild(DxTextAreaComponent, { static: false }) textArea: DxTextAreaComponent
    // Prior to Angular 8
    // @ViewChild(DxTextAreaComponent) textArea: DxTextAreaComponent
    ngAfterViewInit () {
        this.textArea.instance.registerKeyHandler("backspace", function (e) {
            // The argument "e" contains information on the event
        });
        this.textArea.instance.registerKeyHandler("space", function (e) {
            // ...
        });
    }
}
@NgModule({
    imports: [
        // ...
        DxTextAreaModule
    ],
    // ...
})
See Also