/** * @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 table/converters/table-cell-refresh-post-fixer */ /** * Injects a table cell post-fixer into the model which marks the table cell in the differ to have it re-rendered. * * Model `paragraph` inside a table cell can be rendered as `` or `

`. It is rendered as `` if this is the only block * element in that table cell and it does not have any attributes. It is rendered as `

` otherwise. * * When table cell content changes, for example a second `paragraph` element is added, we need to ensure that the first `paragraph` is * re-rendered so it changes from `` to `

`. The easiest way to do it is to re-render the entire table cell. * * @param {module:engine/model/model~Model} model */ export default function injectTableCellRefreshPostFixer( model ) { model.document.registerPostFixer( () => tableCellRefreshPostFixer( model ) ); } function tableCellRefreshPostFixer( model ) { const differ = model.document.differ; // Stores cells to be refreshed so the table cell will be refreshed once for multiple changes. const cellsToRefresh = new Set(); // Counting the paragraph inserts to verify if it increased to more than one paragraph in the current differ. let insertCount = 0; for ( const change of differ.getChanges() ) { const parent = change.type == 'insert' || change.type == 'remove' ? change.position.parent : change.range.start.parent; if ( !parent.is( 'tableCell' ) ) { continue; } if ( change.type == 'insert' ) { insertCount++; } if ( checkRefresh( parent, change.type, insertCount ) ) { cellsToRefresh.add( parent ); } } if ( cellsToRefresh.size ) { for ( const tableCell of cellsToRefresh.values() ) { differ.refreshItem( tableCell ); } return true; } return false; } // Checks if the model table cell requires refreshing to be re-rendered to a proper state in the view. // // This method detects changes that will require renaming `` to `

` (or vice versa) in the view. // // This method is a simple heuristic that checks only a single change and will sometimes give a false positive result when multiple changes // will result in a state that does not require renaming in the view (but will be seen as requiring a refresh). // // For instance: A `` should be renamed to `

` when adding an attribute to a ``. // But adding one attribute and removing another one will result in a false positive: the check for an added attribute will see one // attribute on a paragraph and will falsely qualify such change as adding an attribute to a paragraph without any attribute. // // @param {module:engine/model/element~Element} tableCell The table cell to check. // @param {String} type Type of change. // @param {Number} insertCount The number of inserts in differ. function checkRefresh( tableCell, type, insertCount ) { const hasInnerParagraph = Array.from( tableCell.getChildren() ).some( child => child.is( 'paragraph' ) ); // If there is no paragraph in table cell then the view doesn't require refreshing. // // Why? What we really want to achieve is to make all the old paragraphs (which weren't added in this batch) to be // converted once again, so that the paragraph-in-table-cell converter can correctly create a `

` or a `` element. // If there are no paragraphs in the table cell, we don't care. if ( !hasInnerParagraph ) { return false; } // For attribute change we only refresh if there is a single paragraph as in this case we may want to change existing `` to `

`. if ( type == 'attribute' ) { const attributesCount = Array.from( tableCell.getChild( 0 ).getAttributeKeys() ).length; return tableCell.childCount === 1 && attributesCount < 2; } // For other changes (insert, remove) the `` to `

` change is needed when: // // - another element is added to a single paragraph (childCount becomes >= 2) // - another element is removed and a single paragraph is left (childCount == 1) // // Change is not needed if there were multiple blocks before change. return tableCell.childCount <= ( type == 'insert' ? insertCount + 1 : 1 ); }