ckeditor/ckeditor5-paragraph

/**
 * @license Copyright (c) 2003-2020, CKSource - Frederico Knabben. All rights reserved.
 * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
 */

/**
 * @module paragraph/paragraphcommand
 */

import Command from '@ckeditor/ckeditor5-core/src/command';
import first from '@ckeditor/ckeditor5-utils/src/first';

/**
 * The paragraph command.
 *
 * @extends module:core/command~Command
 */
export default class ParagraphCommand extends Command {
    /**
     * The value of the command. Indicates whether the selection start is placed in a paragraph.
     *
     * @readonly
     * @observable
     * @member {Boolean} #value
     */

    /**
     * @inheritDoc
     */
    refresh() {
        const model = this.editor.model;
        const document = model.document;
        const block = first( document.selection.getSelectedBlocks() );

        this.value = !!block && block.is( 'paragraph' );
        this.isEnabled = !!block && checkCanBecomeParagraph( block, model.schema );
    }

    /**
     * Executes the command. All the blocks (see {@link module:engine/model/schema~Schema}) in the selection
     * will be turned to paragraphs.
     *
     * @fires execute
     * @param {Object} [options] Options for the executed command.
     * @param {module:engine/model/selection~Selection|module:engine/model/documentselection~DocumentSelection} [options.selection]
     * The selection that the command should be applied to.
     * By default, if not provided, the command is applied to the {@link module:engine/model/document~Document#selection}.
     */
    execute( options = {} ) {
        const model = this.editor.model;
        const document = model.document;

        model.change( writer => {
            const blocks = ( options.selection || document.selection ).getSelectedBlocks();

            for ( const block of blocks ) {
                if ( !block.is( 'paragraph' ) && checkCanBecomeParagraph( block, model.schema ) ) {
                    writer.rename( block, 'paragraph' );
                }
            }
        } );
    }
}

// Checks whether the given block can be replaced by a paragraph.
//
// @private
// @param {module:engine/model/element~Element} block A block to be tested.
// @param {module:engine/model/schema~Schema} schema The schema of the document.
// @returns {Boolean}
function checkCanBecomeParagraph( block, schema ) {
    return schema.checkChild( block.parent, 'paragraph' ) && !schema.isObject( block );
}