@ckeditor/ckeditor5-paste-from-office/src/filters/br.js

Paste from Office feature for CKEditor 5.

/**
 * @license Copyright (c) 2003-2024, CKSource Holding sp. z o.o. All rights reserved.
 * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
 */
/**
 * @module paste-from-office/filters/br
 */
import { DomConverter, ViewDocument } from 'ckeditor5/src/engine.js';
/**
 * Transforms `<br>` elements that are siblings to some block element into a paragraphs.
 *
 * @param documentFragment The view structure to be transformed.
 */
export default function transformBlockBrsToParagraphs(documentFragment, writer) {
    const viewDocument = new ViewDocument(writer.document.stylesProcessor);
    const domConverter = new DomConverter(viewDocument, { renderingMode: 'data' });
    const blockElements = domConverter.blockElements;
    const inlineObjectElements = domConverter.inlineObjectElements;
    const elementsToReplace = [];
    for (const value of writer.createRangeIn(documentFragment)) {
        const element = value.item;
        if (element.is('element', 'br')) {
            const nextSibling = findSibling(element, 'forward', writer, { blockElements, inlineObjectElements });
            const previousSibling = findSibling(element, 'backward', writer, { blockElements, inlineObjectElements });
            const nextSiblingIsBlock = isBlockViewElement(nextSibling, blockElements);
            const previousSiblingIsBlock = isBlockViewElement(previousSibling, blockElements);
            // If the <br> is surrounded by blocks then convert it to a paragraph:
            // * <p>foo</p>[<br>]<p>bar</p> -> <p>foo</p>[<p></p>]<p>bar</p>
            // * <p>foo</p>[<br>] -> <p>foo</p>[<p></p>]
            // * [<br>]<p>foo</p> -> [<p></p>]<p>foo</p>
            if (previousSiblingIsBlock || nextSiblingIsBlock) {
                elementsToReplace.push(element);
            }
        }
    }
    for (const element of elementsToReplace) {
        if (element.hasClass('Apple-interchange-newline')) {
            writer.remove(element);
        }
        else {
            writer.replace(element, writer.createElement('p'));
        }
    }
}
/**
 * Returns sibling node, threats inline elements as transparent (but should stop on an inline objects).
 */
function findSibling(viewElement, direction, writer, { blockElements, inlineObjectElements }) {
    let position = writer.createPositionAt(viewElement, direction == 'forward' ? 'after' : 'before');
    // Find first position that is just before a first:
    // * text node,
    // * block element,
    // * inline object element.
    // It's ignoring any inline (non-object) elements like span, strong, etc.
    position = position.getLastMatchingPosition(({ item }) => (item.is('element') &&
        !blockElements.includes(item.name) &&
        !inlineObjectElements.includes(item.name)), { direction });
    return direction == 'forward' ? position.nodeAfter : position.nodeBefore;
}
/**
 * Returns true for view elements that are listed as block view elements.
 */
function isBlockViewElement(node, blockElements) {
    return !!node && node.is('element') && blockElements.includes(node.name);
}