@ckeditor/ckeditor5-basic-styles/src/subscript/subscriptediting.js

Basic styles feature for CKEditor 5.

/**
 * @license Copyright (c) 2003-2025, CKSource Holding sp. z o.o. All rights reserved.
 * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-licensing-options
 */
/**
 * @module basic-styles/subscript/subscriptediting
 */
import { Plugin } from 'ckeditor5/src/core.js';
import { AttributeCommand } from '../attributecommand.js';
const SUBSCRIPT = 'subscript';
/**
 * The subscript editing feature.
 *
 * It registers the `sub` command and introduces the `sub` attribute in the model which renders to the view
 * as a `<sub>` element.
 */
export class SubscriptEditing extends Plugin {
    /**
     * @inheritDoc
     */
    static get pluginName() {
        return 'SubscriptEditing';
    }
    /**
     * @inheritDoc
     */
    static get isOfficialPlugin() {
        return true;
    }
    /**
     * @inheritDoc
     */
    init() {
        const editor = this.editor;
        // Allow sub attribute on text nodes.
        editor.model.schema.extend('$text', { allowAttributes: SUBSCRIPT });
        editor.model.schema.setAttributeProperties(SUBSCRIPT, {
            isFormatting: true,
            copyOnEnter: true
        });
        // Build converter from model to view for data and editing pipelines.
        editor.conversion.attributeToElement({
            model: SUBSCRIPT,
            view: 'sub',
            upcastAlso: [
                {
                    styles: {
                        'vertical-align': 'sub'
                    }
                }
            ]
        });
        // Create sub command.
        editor.commands.add(SUBSCRIPT, new AttributeCommand(editor, SUBSCRIPT));
    }
}