Integrating track changes with your application

The track changes plugin provides an API that lets you manage suggestions added to the document. To save and access suggestions in your database, you first need to integrate this feature.

# Integration methods

This guide will discuss two ways to integrate CKEditor 5 with your suggestions data source:

• A simple “load and save” integration using the TrackChanges plugin API.
• An adapter integration which saves the suggestions data immediately in the database.

The adapter integration is the recommended one because it gives you better control over the data.

It is also recommended to use the track changes plugin together with the comments plugin. Check how to integrate the comments plugin with your WYSIWYG editor.

# Before you start

# Preparing a custom editor setup

To use the track changes plugin, prepare a custom editor setup with the asynchronous version of the track changes feature included.

The easiest way to do that is by using the Builder. Pick a preset and start customizing your editor.

In the “Features” section of the Builder (2nd step), make sure to:

• turn off the “real-time” toggle next to the “Collaboration” group,
• enable the “Collaboration → Track Changes” feature.

Once you finish the setup, the Builder will provide you with the necessary HTML, CSS, and JavaScript code snippets. We will use those code snippets in the next step.

# Setting up a sample project

Once we have a custom editor setup we need a simple JavaScript project to run it. For this, we recommend cloning the basic project template from our repository:

npx -y degit ckeditor/ckeditor5-tutorials-examples/sample-project sample-project
cd sample-project
npm install

Then, install the necessary dependencies:

npm install ckeditor5
npm install ckeditor5-premium-features

This project template uses Vite under the hood and contains 3 source files that we will use: index.html, style.css, and main.js.

It is now the time to use our custom editor setup. Go to the “Installation” section of the Builder and copy the generated code snippets to those 3 files.

# Activating the feature

To use this premium feature, you need to activate it with a license key. Refer to the License key and activation guide for details.

After you have successfully obtained the license key open the main.js file and update the your-license-key string with your license key.

# Building the project

Finally, build the project by running:

npm run dev

When you open the sample in the browser you should see the WYSIWYG editor with the track changes plugin. However, it still does not load or save any data. You will learn how to add data to the track changes plugin later in this guide.

Let’s now dive deeper into the structure of this setup.

# Basic setup’s anatomy

Let’s now go through the key fragments of this basic setup.

# HTML structure

The HTML and CSS structure of the page creates two columns:

• <div class="editor-container__editor"> is the container used by the editor.
• <div class="editor-container__sidebar"> is the container used by the sidebar that holds the annotations (namely track changes).

# JavaScript

The main.js file sets up the editor instance:

• Loads all necessary editor plugins (including the TrackChanges plugin).
• Sets the licenseKey configuration option.
• Sets the sidebar.container configuration option to the container mentioned above.
• Adds the trackChanges button to the editor toolbar.

# Comments

Track changes use the comments plugin to allow discussion in suggestions. You should be familiar with the comments integration guide before you start integrating suggestions.

For that reason, the main.js file obtained in the previous step does the following on top of the track changes plugin setup:

• Loads the Comments plugin (dependency of the TrackChanges plugin).
• Defines the plugin templates:
  • For the CommentsIntegration plugin (learn how to save comments).
  • For the UsersIntegrations plugin that is shared by both track changes and comments features and we will be used in the next steps of this tutorial.
• Adds the comment and commentsArchive buttons to the editor toolbar.

# Next steps

We have set up a simple JavaScript project that runs a basic CKEditor instance with the asynchronous version of the track changes feature. It does not yet handle loading or saving data, though. The next two sections cover the two available integration methods.

# A simple “load and save” integration

In this solution, user and suggestions data is loaded during the editor initialization, and suggestions data is saved after you finish working with the editor (for example, when you submit the form containing the WYSIWYG editor).

This method is recommended only if you can trust your users or if you provide additional validation of the submitted data to make sure that the user changed their suggestions only.

# Loading the data

When the track changes plugin is already included in the editor, you need to create plugins which will initialize users and existing suggestions.

First, dump the users and the suggestions data to a variable that will be available for your plugin.

// Application data will be available under a global variable `appData`.
const appData = {
    // Users data.
    users: [
        {
            id: 'user-1',
            name: 'Mex Haddox'
        },
        {
            id: 'user-2',
            name: 'Zee Croce'
        }
    ],

    // The ID of the current user.
    userId: 'user-1',

    // Comment threads data.
    commentThreads: [
        {
            threadId: 'thread-1',
            comments: [
                {
                    commentId: 'comment-1',
                    authorId: 'user-1',
                    content: '<p>Are we sure we want to use a made-up disorder name?</p>',
                    createdAt: new Date( '09/20/2018 14:21:53' ),
                    attributes: {}
                },
                {
                    commentId: 'comment-2',
                    authorId: 'user-2',
                    content: '<p>Why not?</p>',
                    createdAt: new Date( '09/21/2018 08:17:01' ),
                    attributes: {}
                }
            ],
            context: {
                type: 'text',
                value: 'Bilingual Personality Disorder'
            },
            unlinkedAt: null,
            resolvedAt: null,
            resolvedBy: null,
            attributes: {}
        }
    ],

    // Suggestions data.
    suggestions: [
        {
            id: 'suggestion-1',
            type: 'insertion',
            authorId: 'user-2',
            createdAt: new Date( 2019, 1, 13, 11, 20, 48 ),
            data: null,
            attributes: {}
        },
        {
            id: 'suggestion-2',
            type: 'deletion',
            authorId: 'user-1',
            createdAt: new Date( 2019, 1, 14, 12, 7, 20 ),
            data: null,
            attributes: {}
        },
        {
            id: 'suggestion-3',
            type: 'attribute:bold|ci1tcnk0lkep',
            authorId: 'user-1',
            createdAt: new Date( 2019, 2, 8, 10, 2, 7 ),
            data: {
                key: 'bold',
                oldValue: null,
                newValue: true
            },
            attributes: {
                groupId: 'e29adbb2f3963e522da4d2be03bc5345f'
            }
        }
    ],

    // Editor initial data.
    initialData:
        `<h2>
            <comment-start name="thread-1"></comment-start>
            Bilingual Personality Disorder
            <comment-end name="thread-1"></comment-end>
        </h2>
        <p>
            This may be the first time you hear about this
            <suggestion-start name="insertion:suggestion-1:user-2"></suggestion-start>
            made-up<suggestion-end name="insertion:suggestion-1:user-2"></suggestion-end>
            disorder but it actually is not that far from the truth.
            As recent studies show, the language you speak has more effects on you than you realize.
            According to the studies, the language a person speaks affects their cognition,
            <suggestion-start name="deletion:suggestion-2:user-1"></suggestion-start>
            feelings, <suggestion-end name="deletion:suggestion-2:user-1"></suggestion-end>
            behavior, emotions and hence <strong>their personality</strong>.
        </p>
        <p>
            This shouldn’t come as a surprise
            <a href="https://en.wikipedia.org/wiki/Lateralization_of_brain_function">since we already know</a>
            that different regions of the brain become more active depending on the activity.
            The structure, information and especially
            <suggestion-start name="attribute:bold|ci1tcnk0lkep:suggestion-3:user-1"></suggestion-start><strong>the
            culture of languages<suggestion-end name="attribute:bold|ci1tcnk0lkep:suggestion-3:user-1"></strong></suggestion-end>
            varies substantially
            and the language a person speaks is an essential element of daily life.
        </p>`
};

The Builder’s output sample already provides templates of three plugins: UsersIntegration, CommentsIntegration, and TrackChangesIntegration. Replace them with ones that read the data from appData and use the Users, CommentsRepository, and TrackChanges APIs, respectively:

class UsersIntegration extends Plugin {
    static get requires() {
        return [ 'Users' ];
    }

    static get pluginName() {
        return 'UsersIntegration';
    }

    init() {
        const usersPlugin = this.editor.plugins.get( 'Users' );

        // Load the users data.
        for ( const user of appData.users ) {
            usersPlugin.addUser( user );
        }

        // Set the current user.
        usersPlugin.defineMe( appData.userId );
    }
}

class CommentsIntegration extends Plugin {
    static get requires() {
        return [ 'CommentsRepository', 'UsersIntegration' ];
    }

    static get pluginName() {
        return 'CommentsIntegration';
    }

    init() {
        const commentsRepositoryPlugin = this.editor.plugins.get( 'CommentsRepository' );

        // Load the comment threads data.
        for ( const commentThread of appData.commentThreads ) {
            commentsRepositoryPlugin.addCommentThread( commentThread );
        }
    }
}

class TrackChangesIntegration extends Plugin {
    static get requires() {
        return [ 'TrackChanges', 'UsersIntegration' ];
    }

    static get pluginName() {
        return 'TrackChangesIntegration';
    }

    init() {
        const trackChangesPlugin = this.editor.plugins.get( 'TrackChanges' );

        // Load the suggestions data.
        for ( const suggestion of appData.suggestions ) {
            trackChangesPlugin.addSuggestion( suggestion );
        }
    }
}

Update the editorConfig.initialData property to use appData.initialData value:

const editorConfig = {
    // ...

    initialData: appData.initialData

    // ...
};

And build the project:

npm run dev

You should now we see an editor instance with one comment thread and several track changes suggestions.

# Saving the data

To save the suggestions data you need to get it from the TrackChanges API first. To do this, use the getSuggestions() method.

Then, use the suggestions data to save it in your database in the way you prefer. See the example below.

In index.html add:

<button id="get-data">Get data</button>

In main.js update the ClassicEditor.create() call with a chained then():

ClassicEditor
    .create( /* ... */ )
    .then( editor => {
        // After the editor is initialized, add an action to be performed after a button is clicked.
        const trackChanges = editor.plugins.get( 'TrackChanges' );

        // Get the data on demand.
        document.querySelector( '#get-data' ).addEventListener( 'click', () => {
            const editorData = editor.data.get();
            const suggestionsData = trackChanges.getSuggestions( {
                skipNotAttached: true,
                toJSON: true
            } );

            // Now, use `editorData` and `suggestionsData` to save the data in your application.
            // For example, you can set them as values of hidden input fields.
            console.log( editorData );
            console.log( suggestionsData );
        } );
    } )
    .catch( error => console.error( error ) );

# Demo

// Use the `Save data with track changes` button to see the result...

# Adapter integration

Adapter integration uses an adapter object – provided by you – to immediately save suggestions in your data store. This is the recommended way of integrating track changes with your application because it lets you handle client-server communication more securely. For example, you can check user permissions, validate sent data, or update the data with information obtained on the server side, like the suggestion creation date. You will see how to handle the server response in the following steps.

# Implementation

First, define the adapter using the TrackChanges#adapter setter. Adapter methods allow you to load and save changes in your database.

On the UI side each change in suggestions is performed immediately, however, all adapter actions are asynchronous and are performed in the background. Because of this all adapter methods need to return a Promise. When the promise is resolved, it means that everything went fine and a local change was successfully saved in the data store. When the promise is rejected, the editor throws a CKEditorError error, which works nicely together with the watchdog feature. When you handle the server response you can decide if the promise should be resolved or rejected.

While the adapter is saving the suggestion data, a pending action is automatically added to the editor PendingActions plugin, so you do not have to worry that the editor will be destroyed before the adapter action has finished.

Now you are ready to implement the adapter.

If you have set up the sample project as recommended in the “Before you start” section, open the main.js file and add the following code right after the imports:

// Application data will be available under a global variable `appData`.
const appData = {
    // Users data.
    users: [
        {
            id: 'user-1',
            name: 'Mex Haddox'
        },
        {
            id: 'user-2',
            name: 'Zee Croce'
        }
    ],

    // The ID of the current user.
    userId: 'user-1',

    // Comment threads data.
    commentThreads: [
        {
            threadId: 'thread-1',
            comments: [
                {
                    commentId: 'comment-1',
                    authorId: 'user-1',
                    content: '<p>Are we sure we want to use a made-up disorder name?</p>',
                    createdAt: new Date( '09/20/2018 14:21:53' ),
                    attributes: {}
                },
                {
                    commentId: 'comment-2',
                    authorId: 'user-2',
                    content: '<p>Why not?</p>',
                    createdAt: new Date( '09/21/2018 08:17:01' ),
                    attributes: {}
                }
            ],
            context: {
                type: 'text',
                value: 'Bilingual Personality Disorder'
            },
            unlinkedAt: null,
            resolvedAt: null,
            resolvedBy: null,
            attributes: {}
        }
    ],

    // Editor initial data.
    initialData:
        `<h2>
            <comment-start name="thread-1"></comment-start>
            Bilingual Personality Disorder
            <comment-end name="thread-1"></comment-end>
        </h2>
        <p>
            This may be the first time you hear about this
            <suggestion-start name="insertion:suggestion-1:user-2"></suggestion-start>
            made-up<suggestion-end name="insertion:suggestion-1:user-2"></suggestion-end>
            disorder but it actually is not that far from the truth.
            As recent studies show, the language you speak has more effects on you than you realize.
            According to the studies, the language a person speaks affects their cognition,
            <suggestion-start name="deletion:suggestion-2:user-1"></suggestion-start>
            feelings, <suggestion-end name="deletion:suggestion-2:user-1"></suggestion-end>
            behavior, emotions and hence <strong>their personality</strong>.
        </p>
        <p>
            This shouldn’t come as a surprise
            <a href="https://en.wikipedia.org/wiki/Lateralization_of_brain_function">since we already know</a>
            that different regions of the brain become more active depending on the activity.
            The structure, information and especially
            <suggestion-start name="attribute:bold|ci1tcnk0lkep:suggestion-3:user-1"></suggestion-start><strong>the
            culture of languages<suggestion-end name="attribute:bold|ci1tcnk0lkep:suggestion-3:user-1"></strong></suggestion-end>
            varies substantially
            and the language a person speaks is an essential element of daily life.
        </p>`
};

The Builder’s output sample already provides templates of three plugins: UsersIntegration, CommentsIntegration, and TrackChangesIntegration. Replace them with ones that read the data from appData and use the Users, CommentsRepository, and TrackChanges APIs, respectively:

class UsersIntegration extends Plugin {
    static get requires() {
        return [ 'Users' ];
    }

    static get pluginName() {
        return 'UsersIntegration';
    }

    init() {
        const usersPlugin = this.editor.plugins.get( 'Users' );

        // Load the users data.
        for ( const user of appData.users ) {
            usersPlugin.addUser( user );
        }

        // Set the current user.
        usersPlugin.defineMe( appData.userId );
    }
}

class CommentsIntegration extends Plugin {
    static get requires() {
        return [ 'CommentsRepository', 'UsersIntegration' ];
    }

    static get pluginName() {
        return 'CommentsIntegration';
    }

    init() {
        const commentsRepositoryPlugin = this.editor.plugins.get( 'CommentsRepository' );

        // Load the comment threads data.
        for ( const commentThread of appData.commentThreads ) {
            commentsRepositoryPlugin.addCommentThread( commentThread );
        }
    }
}

class TrackChangesIntegration extends Plugin {
    static get requires() {
        return [ 'TrackChanges', 'UsersIntegration' ];
    }

    static get pluginName() {
        return 'TrackChangesIntegration';
    }

    init() {
        const trackChangesPlugin = this.editor.plugins.get( 'TrackChanges' );

        // Set the adapter to the `TrackChanges#adapter` property.
        trackChangesPlugin.adapter = {
            getSuggestion: suggestionId => {
                console.log( 'Getting suggestion', suggestionId );

                // Write a request to your database here.
                // The returned `Promise` should be resolved with the suggestion
                // data object when the request has finished.
                switch ( suggestionId ) {
                    case 'suggestion-1':
                        return Promise.resolve( {
                            id: suggestionId,
                            type: 'insertion',
                            authorId: 'user-2',
                            createdAt: new Date(),
                            data: null,
                            attributes: {}
                        } );
                    case 'suggestion-2':
                        return Promise.resolve( {
                            id: suggestionId,
                            type: 'deletion',
                            authorId: 'user-1',
                            createdAt: new Date(),
                            data: null,
                            attributes: {}
                        } );
                    case 'suggestion-3':
                        return Promise.resolve( {
                            id: 'suggestion-3',
                            type: 'attribute:bold|ci1tcnk0lkep',
                            authorId: 'user-1',
                            createdAt: new Date( 2019, 2, 8, 10, 2, 7 ),
                            data: {
                                key: 'bold',
                                oldValue: null,
                                newValue: true
                            },
                            attributes: {
                                groupId: 'e29adbb2f3963e522da4d2be03bc5345f'
                            }
                        } );
                }
            },

            addSuggestion: suggestionData => {
                console.log( 'Suggestion added', suggestionData );

                // Write a request to your database here.
                // The returned `Promise` should be resolved when the request
                // has finished. When the promise resolves with the suggestion data
                // object, it will update the editor suggestion using the provided data.
                return Promise.resolve( {
                    createdAt: new Date()       // Should be set on the server side.
                } );
            },

            updateSuggestion: ( id, suggestionData ) => {
                console.log( 'Suggestion updated', id, suggestionData );

                // Write a request to your database here.
                // The returned `Promise` should be resolved when the request
                // has finished.
                return Promise.resolve();
            }
        };

        // In order to load comments added to suggestions, you
        // should also integrate the comments adapter.
    }
}

Update the editorConfig.initialData property to use appData.initialData value:

const editorConfig = {
    // ...

    initialData: appData.initialData

    // ...
};

And build the project:

npm run dev

You should now we see an editor instance with one comment thread and several track changes suggestions. The adapter is now ready to use with your rich text editor.

# Demo

// Add a suggestion to see the result...

Since the track changes adapter saves suggestions immediately after they are performed, it is also recommended to use the Autosave plugin to save the editor content after each change.

# Why is there no event when I accept or discard a suggestion?

Note that when you discard or accept a suggestion, no event is fired in the adapter. This is because the suggestion is never removed from the editor during the editing session. You are able to restore it using undo (Cmd+Z or Ctrl+Z). The same happens when you remove a paragraph with suggestions – there will be no event fired because no data is really removed.

However, to make sure that you do not keep outdated suggestions in your database, you should do a cleanup when the editor is destroyed or closed. You can compare the suggestions stored in the editor data with the suggestions stored in your database and remove all the suggestions that are no longer in the editor data from your database.

# Track changes samples

Please visit the ckeditor5-collaboration-samples GitHub repository to find several sample integrations of the track changes feature.