Mentions (autocompletion)

The mention feature enables smart autocompletion based on user input. When you type a pre-configured marker, such as @ or #, a panel displays with autocomplete suggestions.

# Demo

You can type the “@” character to invoke the mention autocomplete UI. The demo below is configured to suggest a static list of names (Barney, Lily, Marry Ann, Marshall, Robin, and Ted).

You can read more about possible implementations of the mention feature in a dedicated blog post.

# Installation

After installing the editor, add the feature to your plugin list and toolbar configuration:

import { ClassicEditor, Mention } from 'ckeditor5';

ClassicEditor
    .create( document.querySelector( '#editor' ), {
        plugins: [ Mention, /* ... */ ],
        mention: {
            // Configuration.
            // ...
        }
    } )
    .then( /* ... */ )
    .catch( /* ... */ );

# Configuration

The minimal configuration of the mention feature requires defining a feed and a marker. You can also define the minimumCharacters parameter, setting the number of letters after which the autocomplete panel will show up. Moreover, feed items’ IDs may include whitespaces.

The code snippet below was used to configure the demo above. It defines the list of names that the editor will autocomplete after the user types the “@” character.

ClassicEditor
    .create( document.querySelector( '#editor' ), {
        // This feature is available in the superbuild only.
        // See the "Installation" section.
        plugins: [ Mention, /* ... */ ],

        mention: {
            feeds: [
                {
                    marker: '@',
                    feed: [ '@Barney', '@Lily', '@Marry Ann', '@Marshall', '@Robin', '@Ted' ],
                    minimumCharacters: 1
                }
            ]
        }
    } )
    .then( /* ... */ )
    .catch( /* ... */ );

Additionally, you can configure:

• How the item is rendered in the autocomplete panel (via setting itemRenderer). See Customizing the autocomplete list.
• How the item is converted during the conversion. See Customizing the output.
• Multiple feeds. The demo above uses only one feed, which is triggered by the '@' character. You can define multiple feeds but they must use different markers. For example, you can use '@' for people and '#' for tags.

# Providing the feed

The feed can be provided as:

• A static array – Good for scenarios with a relatively small set of autocomplete items.
• A callback – Provides more control over the returned list of items.

When using a callback you can return a Promise that resolves with the list of matching feed items. These can be simple strings or plain objects with at least the name property. The other properties of this object can later be used when customizing the autocomplete list or customizing the output.

The callback receives the query text which should be used to filter item suggestions. It should return a Promise and resolve it with an array of items that match the feed text.

ClassicEditor
    .create( document.querySelector( '#editor' ), {
        // This feature is available in the superbuild only.
        // See the "Installation" section.
        plugins: [ Mention, /* ... */ ],

        mention: {
            feeds: [
                {
                    marker: '@',
                    feed: getFeedItems
                }
            }
        ]
    } )
    .then( /* ... */ )
    .catch( /* ... */ );

const items = [
    { id: '@swarley', userId: '1', name: 'Barney Stinson', link: 'https://www.imdb.com/title/tt0460649/characters/nm0000439' },
    { id: '@lilypad', userId: '2', name: 'Lily Aldrin', link: 'https://www.imdb.com/title/tt0460649/characters/nm0004989' },
    { id: '@marry', userId: '3', name: 'Marry Ann Lewis', link: 'https://www.imdb.com/title/tt0460649/characters/nm1130627' },
    { id: '@marshmallow', userId: '4', name: 'Marshall Eriksen', link: 'https://www.imdb.com/title/tt0460649/characters/nm0781981' },
    { id: '@rsparkles', userId: '5', name: 'Robin Scherbatsky', link: 'https://www.imdb.com/title/tt0460649/characters/nm1130627' },
    { id: '@tdog', userId: '6', name: 'Ted Mosby', link: 'https://www.imdb.com/title/tt0460649/characters/nm1102140' }
];

function getFeedItems( queryText ) {
    // As an example of an asynchronous action, return a promise
    // that resolves after a 100ms timeout.
    // This can be a server request or any sort of delayed action.
    return new Promise( resolve => {
        setTimeout( () => {
            const itemsToDisplay = items
                // Filter out the full list of all items to only those matching the query text.
                .filter( isItemMatching )
                // Return 10 items max - needed for generic queries when the list may contain hundreds of elements.
                .slice( 0, 10 );

            resolve( itemsToDisplay );
        }, 100 );
    } );

    // Filtering function - it uses the `name` and `username` properties of an item to find a match.
    function isItemMatching( item ) {
        // Make the search case-insensitive.
        const searchString = queryText.toLowerCase();

        // Include an item in the search results if the name or username includes the current user input.
        return (
            item.name.toLowerCase().includes( searchString ) ||
            item.id.toLowerCase().includes( searchString )
        );
    }
}

A full, working demo with all possible customizations and its source code is available at the end of this section.

# Customizing the autocomplete list

# Styling

The items displayed in the autocomplete list can be customized by defining the itemRenderer callback.

This callback takes a feed item (it contains at least the name property) and must return a new DOM element.

ClassicEditor
    .create( document.querySelector( '#editor' ), {
        plugins: [ Mention, /* ... */ ],
        mention: {
            feeds: [
                {
                    feed: [ /* ... */ ],
                    // Define the custom item renderer.
                    itemRenderer: customItemRenderer
                }
            ]
        }
    } )
    .then( /* ... */ )
    .catch( /* ... */ );

function customItemRenderer( item ) {
    const itemElement = document.createElement( 'span' );

    itemElement.classList.add( 'custom-item' );
    itemElement.id = `mention-list-item-id-${ item.userId }`;
    itemElement.textContent = `${ item.name } `;

    const usernameElement = document.createElement( 'span' );

    usernameElement.classList.add( 'custom-item-username' );
    usernameElement.textContent = item.id;

    itemElement.appendChild( usernameElement );

    return itemElement;
}

A full, working demo with all possible customizations and its source code is available at the end of this section.

# List length

The number of items displayed in the autocomplete list can be customized by defining the dropdownLimit option.

ClassicEditor
    .create( document.querySelector( '#editor' ), {
        plugins: [ Mention, /* ... */ ],
        mention: {
            // Define the custom number of visible mentions.
            dropdownLimit: 4
            feeds: [
                { /* ... */ }
                // More feeds.
                // ...
            ]
        }
    } )
    .then( /* ... */ )
    .catch( /* ... */ );

A full, working demo with all possible customizations and its source code is available at the end of this section.

# Customizing the text inserted into the editor

You can control the text inserted into the editor when creating a mention via the text property in the mention configuration.

ClassicEditor
    .create( editorElement, {
        plugins: [ Mention, ... ],
        mention: {
            feeds: [
                // Feed items as objects.
                {
                    marker: '@',
                    feed: [
                        {
                            id: '@Barney',
                            fullName: 'Barney Stinson',
                            // Custom text to be inserted into the editor
                            text: 'Swarley'
                        },
                        // ...
                    ]
                },
            ]
        }
    } )
    .then( /* ... */ )
    .catch( /* ... */ );

The string that you specify in this property will be displayed in the editor when a mention is created.

# Customizing the output

To change the markup generated by the editor for mentions, you can overwrite the default converter of the mention feature. To do that, you must specify both upcast and downcast converters using AttributeElement.

The example below defines a plugin that overrides the default output:

<span data-mention="@Ted" class="mention">@Ted</span>

To a link:

<a class="mention" data-mention="@Ted" data-user-id="5" href="https://www.imdb.com/title/tt0460649/characters/nm1102140">@tdog</a>

The converters must be defined with a 'high' priority to be executed before the link feature’s converter and before the default converter of the mention feature. A mention is stored in the model as a text attribute that stores an object (see MentionFeedItem).

To control how the mention element is wrapped by other attribute elements (like bold, italic, etc) set its priority. To replicate default plugin behavior and make mention to be wrapped by other elements set priority to 20.

By default, attribute elements that are next to each other and have the same value will be rendered as a single HTML element. To prevent this, the model attribute value object exposes a unique ID of each inserted mention to the model as uid. To prevent merging subsequent mentions, set it as id.

Note: The feature prevents copying fragments of existing mentions. If only a part of a mention is selected, it will be copied as plain text. The internal converter with the 'highest' priority controls this behavior. We do not recommend adding mention converters with the 'highest' priority to avoid collisions and quirky results.

ClassicEditor
    .create( document.querySelector( '#editor' ), {
        plugins: [ Mention, MentionCustomization, /* ... */ ], // Add the custom mention plugin function.
        mention: {
            // Configuration.
            // ...
        }
    } )
    .then( /* ... */ )
    .catch( /* ... */ );

function MentionCustomization( editor ) {
    // The upcast converter will convert view <a class="mention" href="" data-user-id="">
    // elements to the model 'mention' text attribute.
    editor.conversion.for( 'upcast' ).elementToAttribute( {
        view: {
            name: 'a',
            key: 'data-mention',
            classes: 'mention',
            attributes: {
                href: true,
                'data-user-id': true
            }
        },
        model: {
            key: 'mention',
            value: viewItem => {
                // The mention feature expects that the mention attribute value
                // in the model is a plain object with a set of additional attributes.
                // In order to create a proper object use the toMentionAttribute() helper method:
                const mentionAttribute = editor.plugins.get( 'Mention' ).toMentionAttribute( viewItem, {
                    // Add any other properties that you need.
                    link: viewItem.getAttribute( 'href' ),
                    userId: viewItem.getAttribute( 'data-user-id' )
                } );

                return mentionAttribute;
            }
        },
        converterPriority: 'high'
    } );

    // Downcast the model 'mention' text attribute to a view <a> element.
    editor.conversion.for( 'downcast' ).attributeToElement( {
        model: 'mention',
        view: ( modelAttributeValue, { writer } ) => {
            // Do not convert empty attributes (lack of value means no mention).
            if ( !modelAttributeValue ) {
                return;
            }

            return writer.createAttributeElement( 'a', {
                class: 'mention',
                'data-mention': modelAttributeValue.id,
                'data-user-id': modelAttributeValue.userId,
                'href': modelAttributeValue.link
            }, {
                // Make mention attribute to be wrapped by other attribute elements.
                priority: 20,
                // Prevent merging mentions together.
                id: modelAttributeValue.uid
            } );
        },
        converterPriority: 'high'
    } );
}

A full, working demo with all possible customizations and its source code is available at the end of this section.

# Fully customized mention feed

Below is an example of a customized mention feature that:

• Uses a feed of items with additional properties (id, username, link).
• Renders custom item views in the autocomplete panel.
• Converts a mention to an <a> element instead of a <span>.
• Limits the number of mentions to four elements.

# Source code

ClassicEditor
    .create( document.querySelector( '#snippet-mention-customization' ), {
        plugins: [ Mention, MentionCustomization, /* ... */ ],
        mention: {
            dropdownLimit: 4,
            feeds: [
                {
                    marker: '@',
                    feed: getFeedItems,
                    itemRenderer: customItemRenderer
                }
            ]
        }
    } )
    .then( editor => {
        window.editor = editor;
    } )
    .catch( err => {
        console.error( err.stack );
    } );

function MentionCustomization( editor ) {
    // The upcast converter will convert <a class="mention" href="" data-user-id="">
    // elements to the model 'mention' attribute.
    editor.conversion.for( 'upcast' ).elementToAttribute( {
        view: {
            name: 'a',
            key: 'data-mention',
            classes: 'mention',
            attributes: {
                href: true,
                'data-user-id': true
            }
        },
        model: {
            key: 'mention',
            value: viewItem => {
                // The mention feature expects that the mention attribute value
                // in the model is a plain object with a set of additional attributes.
                // In order to create a proper object, use the toMentionAttribute helper method:
                const mentionAttribute = editor.plugins.get( 'Mention' ).toMentionAttribute( viewItem, {
                    // Add any other properties that you need.
                    link: viewItem.getAttribute( 'href' ),
                    userId: viewItem.getAttribute( 'data-user-id' )
                } );

                return mentionAttribute;
            }
        },
        converterPriority: 'high'
    } );

    // Downcast the model 'mention' text attribute to a view <a> element.
    editor.conversion.for( 'downcast' ).attributeToElement( {
        model: 'mention',
        view: ( modelAttributeValue, { writer } ) => {
            // Do not convert empty attributes (lack of value means no mention).
            if ( !modelAttributeValue ) {
                return;
            }

            return writer.createAttributeElement( 'a', {
                class: 'mention',
                'data-mention': modelAttributeValue.id,
                'data-user-id': modelAttributeValue.userId,
                'href': modelAttributeValue.link
            }, {
                // Make mention attribute to be wrapped by other attribute elements.
                priority: 20,
                // Prevent merging mentions together.
                id: modelAttributeValue.uid
            } );
        },
        converterPriority: 'high'
    } );
}

const items = [
    { id: '@swarley', userId: '1', name: 'Barney Stinson', link: 'https://www.imdb.com/title/tt0460649/characters/nm0000439' },
    { id: '@lilypad', userId: '2', name: 'Lily Aldrin', link: 'https://www.imdb.com/title/tt0460649/characters/nm0004989' },
    { id: '@marry', userId: '3', name: 'Marry Ann Lewis', link: 'https://www.imdb.com/title/tt0460649/characters/nm1130627' },
    { id: '@marshmallow', userId: '4', name: 'Marshall Eriksen', link: 'https://www.imdb.com/title/tt0460649/characters/nm0781981' },
    { id: '@rsparkles', userId: '5', name: 'Robin Scherbatsky', link: 'https://www.imdb.com/title/tt0460649/characters/nm1130627' },
    { id: '@tdog', userId: '6', name: 'Ted Mosby', link: 'https://www.imdb.com/title/tt0460649/characters/nm1102140' }
];

function getFeedItems( queryText ) {
    // As an example of an asynchronous action, return a promise
    // that resolves after a 100ms timeout.
    // This can be a server request or any sort of delayed action.
    return new Promise( resolve => {
        setTimeout( () => {
            const itemsToDisplay = items
                // Filter out the full list of all items to only those matching the query text.
                .filter( isItemMatching )
                // Return 10 items max - needed for generic queries when the list may contain hundreds of elements.
                .slice( 0, 10 );

            resolve( itemsToDisplay );
        }, 100 );
    } );

    // Filtering function - it uses `name` and `username` properties of an item to find a match.
    function isItemMatching( item ) {
        // Make the search case-insensitive.
        const searchString = queryText.toLowerCase();

        // Include an item in the search results if name or username includes the current user input.
        return (
            item.name.toLowerCase().includes( searchString ) ||
            item.id.toLowerCase().includes( searchString )
        );
    }
}

function customItemRenderer( item ) {
    const itemElement = document.createElement( 'span' );

    itemElement.classList.add( 'custom-item' );
    itemElement.id = `mention-list-item-id-${ item.userId }`;
    itemElement.textContent = `${ item.name } `;

    const usernameElement = document.createElement( 'span' );

    usernameElement.classList.add( 'custom-item-username' );
    usernameElement.textContent = item.id;

    itemElement.appendChild( usernameElement );

    return itemElement;
}

# Colors and styles

# Using CSS variables

The mention feature uses the power of CSS variables which are defined in the Lark theme style sheet. Thanks to that, mention styles can be easily customized:

:root {
    /* Make the mention background blue. */
    --ck-color-mention-background: hsla(220, 100%, 54%, 0.4);

    /* Make the mention text dark grey. */
    --ck-color-mention-text: hsl(0, 0%, 15%);
}

# Comments with mentions

It is possible to configure the Mentions feature to work with the Comments feature. Here you can find detailed guidance on that matter.

# Related features

In addition to enabling mentions, you may want to check the following productivity features:

• Automatic text transformation – Lets you automatically turn snippets such as (tm) into ™ and "foo" into “foo”.
• Autolink – Turns the links and email addresses typed or pasted into the editor into active URLs.
• Autoformatting – Lets you quickly apply formatting to the content you are writing.

# Common API

The Mention plugin registers:

• The 'mention' command implemented by MentionCommand.

  You can insert a mention element by executing the following code:

  editor.execute( 'mention', { marker: '@', mention: '@John' } );
  

# Contribute

The source code of the feature is available on GitHub at https://github.com/ckeditor/ckeditor5/tree/master/packages/ckeditor5-mention.