History in Angular Document editor component

21 Sep 20221 minute to read

Document Editor tracks the history of all editing actions done in the document, which allows undo and redo functionality.

Enable or disable history

Inject the EditorHistory module in your application to provide history preservation functionality for DocumentEditor. Refer to the following code example.

import { Component, ViewEncapsulation } from '@angular/core';
import { DocumentEditorComponent, SfdtExportService, SelectionService, EditorService, EditorHistoryService } from '@syncfusion/ej2-angular-documenteditor';

@Component({
    selector: 'app-container',
    //specifies the template string for the Document Editor component
    template: `<ejs-documenteditor #document_editor  id="container" style="width: 100%;height: 100%;display:block" [isReadOnly]=false [enableSelection]=true [enableEditor]=true [enableEditorHistory]=true >
    </ejs-documenteditor>`,
    encapsulation: ViewEncapsulation.None,
    //Inject require modules.
    providers: [SfdtExportService, SelectionService, EditorService, EditorHistoryService]
})

export class AppComponent {

}

You can enable or disable history preservation for a document editor instance any time using the ‘enableEditorHistory’ property. Refer to the following sample code.

this.documentEditor.enableEditorHistory = false;

Undo and redo

You can perform undo and redo by CTRL+Z and CTRL+Y keyboard shortcuts. Document Editor exposes API to do it programmatically.
To undo the last editing operation in document editor, refer to the following sample code.

this.documentEditor.editorHistory.undo();

To redo the last undone action, refer to the following code example.

this.documentEditor.editorHistory.redo();

Stack size

History of editing actions will be maintained in stack, so that the last item will be reverted first. By default, document editor limits the size of undo and redo stacks to 500 each respectively. However, you can customize this limit. Refer to the following sample code.

//Set undo limit.
this.documentEditor.editorHistory.undoLimit = 400;
//Set redo limit.
this.documentEditor.editorHistory.redoLimit = 400;

See Also