@ckeditor/ckeditor5-engine
Version:
The editing engine of CKEditor 5 – the best browser-based rich text editor.
697 lines (696 loc) • 34.3 kB
JavaScript
/**
* @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 engine/model/utils/insertcontent
*/
import { ModelDocumentSelection } from '../documentselection.js';
import { ModelElement } from '../element.js';
import { ModelLivePosition } from '../liveposition.js';
import { ModelLiveRange } from '../liverange.js';
import { ModelPosition } from '../position.js';
import { ModelRange } from '../range.js';
import { CKEditorError } from '@ckeditor/ckeditor5-utils';
/**
* Inserts content into the editor (specified selection) as one would expect the paste functionality to work.
*
* It takes care of removing the selected content, splitting elements (if needed), inserting elements and merging elements appropriately.
*
* Some examples:
*
* ```html
* <p>x^</p> + <p>y</p> => <p>x</p><p>y</p> => <p>xy[]</p>
* <p>x^y</p> + <p>z</p> => <p>x</p>^<p>y</p> + <p>z</p> => <p>x</p><p>z</p><p>y</p> => <p>xz[]y</p>
* <p>x^y</p> + <img /> => <p>x</p>^<p>y</p> + <img /> => <p>x</p><img /><p>y</p>
* <p>x</p><p>^</p><p>z</p> + <p>y</p> => <p>x</p><p>y[]</p><p>z</p> (no merging)
* <p>x</p>[<img />]<p>z</p> + <p>y</p> => <p>x</p>^<p>z</p> + <p>y</p> => <p>x</p><p>y[]</p><p>z</p>
* ```
*
* If an instance of {@link module:engine/model/selection~ModelSelection} is passed as `selectable` it will be modified
* to the insertion selection (equal to a range to be selected after insertion).
*
* If `selectable` is not passed, the content will be inserted using the current selection of the model document.
*
* **Note:** Use {@link module:engine/model/model~Model#insertContent} instead of this function.
* This function is only exposed to be reusable in algorithms which change the {@link module:engine/model/model~Model#insertContent}
* method's behavior.
*
* @param model The model in context of which the insertion should be performed.
* @param content The content to insert.
* @param selectable Selection into which the content should be inserted.
* @returns Range which contains all the performed changes. This is a range that, if removed,
* would return the model to the state before the insertion. If no changes were preformed by `insertContent`, returns a range collapsed
* at the insertion position.
* @internal
*/
export function insertContent(model, content, selectable) {
return model.change(writer => {
const selection = selectable ? selectable : model.document.selection;
if (!selection.isCollapsed) {
model.deleteContent(selection, { doNotAutoparagraph: true });
}
const insertion = new Insertion(model, writer, selection.anchor);
const fakeMarkerElements = [];
let nodesToInsert;
if (content.is('documentFragment')) {
// If document fragment has any markers, these markers should be inserted into the model as well.
if (content.markers.size) {
const markersPosition = [];
for (const [name, range] of content.markers) {
const { start, end } = range;
const isCollapsed = start.isEqual(end);
markersPosition.push({ position: start, name, isCollapsed }, { position: end, name, isCollapsed });
}
// Markers position is sorted backwards to ensure that the insertion of fake markers will not change
// the position of the next markers.
markersPosition.sort(({ position: posA }, { position: posB }) => posA.isBefore(posB) ? 1 : -1);
for (const { position, name, isCollapsed } of markersPosition) {
let fakeElement = null;
let collapsed = null;
const isAtBeginning = position.parent === content && position.isAtStart;
const isAtEnd = position.parent === content && position.isAtEnd;
// We have two ways of handling markers. In general, we want to add temporary <$marker> model elements to
// represent marker boundaries. These elements will be inserted into content together with the rest
// of the document fragment. After insertion is done, positions for these elements will be read
// and proper, actual markers will be created in the model and fake elements will be removed.
//
// However, if the <$marker> element is at the beginning or at the end of the document fragment,
// it may affect how the inserted content is merged with current model, impacting the insertion
// result. To avoid that, we don't add <$marker> elements at these positions. Instead, we will use
// `Insertion#getAffectedRange()` to figure out new positions for these marker boundaries.
if (!isAtBeginning && !isAtEnd) {
fakeElement = writer.createElement('$marker');
writer.insert(fakeElement, position);
}
else if (isCollapsed) {
// Save whether the collapsed marker was at the beginning or at the end of document fragment
// to know where to create it after the insertion is done.
collapsed = isAtBeginning ? 'start' : 'end';
}
fakeMarkerElements.push({
name,
element: fakeElement,
collapsed
});
}
}
nodesToInsert = content.getChildren();
}
else {
nodesToInsert = [content];
}
insertion.handleNodes(nodesToInsert);
let newRange = insertion.getSelectionRange();
if (content.is('documentFragment') && fakeMarkerElements.length) {
// After insertion was done, the selection was set but the model contains fake <$marker> elements.
// These <$marker> elements will be now removed. Because of that, we will need to fix the selection.
// We will create a live range that will automatically be update as <$marker> elements are removed.
const selectionLiveRange = newRange ? ModelLiveRange.fromRange(newRange) : null;
// Marker name -> [ start position, end position ].
const markersData = {};
// Note: `fakeMarkerElements` are sorted backwards. However, now, we want to handle the markers
// from the beginning, so that existing <$marker> elements do not affect markers positions.
// This is why we iterate from the end to the start.
for (let i = fakeMarkerElements.length - 1; i >= 0; i--) {
const { name, element, collapsed } = fakeMarkerElements[i];
const isStartBoundary = !markersData[name];
if (isStartBoundary) {
markersData[name] = [];
}
if (element) {
// Read fake marker element position to learn where the marker should be created.
const elementPosition = writer.createPositionAt(element, 'before');
markersData[name].push(elementPosition);
writer.remove(element);
}
else {
// If the fake marker element does not exist, it means that the marker boundary was at the beginning or at the end.
const rangeOnInsertion = insertion.getAffectedRange();
if (!rangeOnInsertion) {
// If affected range is `null` it means that nothing was in the document fragment or all content was filtered out.
// Some markers that were in the filtered content may be removed (partially or totally).
// Let's handle only those markers that were at the beginning or at the end of the document fragment.
if (collapsed) {
markersData[name].push(insertion.position);
}
continue;
}
if (collapsed) {
// If the marker was collapsed at the beginning or at the end of the document fragment,
// put both boundaries at the beginning or at the end of inserted range (to keep the marker collapsed).
markersData[name].push(rangeOnInsertion[collapsed]);
}
else {
markersData[name].push(isStartBoundary ? rangeOnInsertion.start : rangeOnInsertion.end);
}
}
}
for (const [name, [start, end]] of Object.entries(markersData)) {
// For now, we ignore markers if they are included in the filtered-out content.
// In the future implementation we will improve that case to create markers that are not filtered out completely.
if (start && end && start.root === end.root && start.root.document && !writer.model.markers.has(name)) {
writer.addMarker(name, {
usingOperation: true,
affectsData: true,
range: new ModelRange(start, end)
});
}
}
if (selectionLiveRange) {
newRange = selectionLiveRange.toRange();
selectionLiveRange.detach();
}
}
/* istanbul ignore else -- @preserve */
if (newRange) {
if (selection instanceof ModelDocumentSelection) {
writer.setSelection(newRange);
}
else {
selection.setTo(newRange);
}
}
else {
// We are not testing else because it's a safe check for unpredictable edge cases:
// an insertion without proper range to select.
//
// @if CK_DEBUG // console.warn( 'Cannot determine a proper selection range after insertion.' );
}
const affectedRange = insertion.getAffectedRange() || model.createRange(selection.anchor);
insertion.destroy();
return affectedRange;
});
}
/**
* Utility class for performing content insertion.
*/
class Insertion {
/**
* The model in context of which the insertion should be performed.
*/
model;
/**
* Batch to which operations will be added.
*/
writer;
/**
* The position at which (or near which) the next node will be inserted.
*/
position;
/**
* Elements with which the inserted elements can be merged.
*
* ```html
* <p>x^</p><p>y</p> + <p>z</p> (can merge to <p>x</p>)
* <p>x</p><p>^y</p> + <p>z</p> (can merge to <p>y</p>)
* <p>x^y</p> + <p>z</p> (can merge to <p>xy</p> which will be split during the action,
* so both its pieces will be added to this set)
* ```
*/
canMergeWith;
/**
* Schema of the model.
*/
schema;
/**
* The temporary ModelDocumentFragment used for grouping multiple nodes for single insert operation.
*/
_documentFragment;
/**
* The current position in the temporary ModelDocumentFragment.
*/
_documentFragmentPosition;
/**
* The reference to the first inserted node.
*/
_firstNode = null;
/**
* The reference to the last inserted node.
*/
_lastNode = null;
/**
* The reference to the last auto paragraph node.
*/
_lastAutoParagraph = null;
/**
* The array of nodes that should be cleaned of not allowed attributes.
*/
_filterAttributesOf = [];
/**
* Beginning of the affected range. See {@link module:engine/model/utils/insertcontent~Insertion#getAffectedRange}.
*/
_affectedStart = null;
/**
* End of the affected range. See {@link module:engine/model/utils/insertcontent~Insertion#getAffectedRange}.
*/
_affectedEnd = null;
_nodeToSelect = null;
constructor(model, writer, position) {
this.model = model;
this.writer = writer;
this.position = position;
this.canMergeWith = new Set([this.position.parent]);
this.schema = model.schema;
this._documentFragment = writer.createDocumentFragment();
this._documentFragmentPosition = writer.createPositionAt(this._documentFragment, 0);
}
/**
* Handles insertion of a set of nodes.
*
* @param nodes Nodes to insert.
*/
handleNodes(nodes) {
for (const node of Array.from(nodes)) {
this._handleNode(node);
}
// Insert nodes collected in temporary ModelDocumentFragment.
this._insertPartialFragment();
// If there was an auto paragraph then we might need to adjust the end of insertion.
if (this._lastAutoParagraph) {
this._updateLastNodeFromAutoParagraph(this._lastAutoParagraph);
}
// After the content was inserted we may try to merge it with its next sibling if the selection was in it initially.
// Merging with the previous sibling was performed just after inserting the first node to the document.
this._mergeOnRight();
// TMP this will become a post-fixer.
this.schema.removeDisallowedAttributes(this._filterAttributesOf, this.writer);
this._filterAttributesOf = [];
}
/**
* Updates the last node after the auto paragraphing.
*
* @param node The last auto paragraphing node.
*/
_updateLastNodeFromAutoParagraph(node) {
const positionAfterLastNode = this.writer.createPositionAfter(this._lastNode);
const positionAfterNode = this.writer.createPositionAfter(node);
// If the real end was after the last auto paragraph then update relevant properties.
if (positionAfterNode.isAfter(positionAfterLastNode)) {
this._lastNode = node;
/* istanbul ignore if -- @preserve */
if (this.position.parent != node || !this.position.isAtEnd) {
// Algorithm's correctness check. We should never end up here but it's good to know that we did.
// At this point the insertion position should be at the end of the last auto paragraph.
// Note: This error is documented in other place in this file.
throw new CKEditorError('insertcontent-invalid-insertion-position', this);
}
this.position = positionAfterNode;
this._setAffectedBoundaries(this.position);
}
}
/**
* Returns range to be selected after insertion.
* Returns `null` if there is no valid range to select after insertion.
*/
getSelectionRange() {
if (this._nodeToSelect) {
return ModelRange._createOn(this._nodeToSelect);
}
return this.model.schema.getNearestSelectionRange(this.position);
}
/**
* Returns a range which contains all the performed changes. This is a range that, if removed, would return the model to the state
* before the insertion. Returns `null` if no changes were done.
*/
getAffectedRange() {
if (!this._affectedStart) {
return null;
}
return new ModelRange(this._affectedStart, this._affectedEnd);
}
/**
* Destroys `Insertion` instance.
*/
destroy() {
if (this._affectedStart) {
this._affectedStart.detach();
}
if (this._affectedEnd) {
this._affectedEnd.detach();
}
}
/**
* Handles insertion of a single node.
*/
_handleNode(node) {
// Split the position.parent's branch up to a point where the node can be inserted.
// If it isn't allowed in the whole branch, then of course don't split anything.
if (!this._checkAndSplitToAllowedPosition(node)) {
// Handle element children if it's not an object (strip container).
if (!this.schema.isObject(node)) {
this._handleDisallowedNode(node);
}
return;
}
// Add node to the current temporary ModelDocumentFragment.
this._appendToFragment(node);
// Store the first and last nodes for easy access for merging with sibling nodes.
if (!this._firstNode) {
this._firstNode = node;
}
this._lastNode = node;
}
/**
* Inserts the temporary ModelDocumentFragment into the model.
*/
_insertPartialFragment() {
if (this._documentFragment.isEmpty) {
return;
}
const livePosition = ModelLivePosition.fromPosition(this.position, 'toNext');
this._setAffectedBoundaries(this.position);
// If the very first node of the whole insertion process is inserted, insert it separately for OT reasons (undo).
// Note: there can be multiple calls to `_insertPartialFragment()` during one insertion process.
// Note: only the very first node can be merged so we have to do separate operation only for it.
if (this._documentFragment.getChild(0) == this._firstNode) {
this.writer.insert(this._firstNode, this.position);
// We must merge the first node just after inserting it to avoid problems with OT.
// (See: https://github.com/ckeditor/ckeditor5/pull/8773#issuecomment-760945652).
this._mergeOnLeft();
this.position = livePosition.toPosition();
}
// Insert the remaining nodes from document fragment.
if (!this._documentFragment.isEmpty) {
this.writer.insert(this._documentFragment, this.position);
}
this._documentFragmentPosition = this.writer.createPositionAt(this._documentFragment, 0);
this.position = livePosition.toPosition();
livePosition.detach();
}
/**
* @param node The disallowed node which needs to be handled.
*/
_handleDisallowedNode(node) {
// If the node is an element, try inserting its children (strip the parent).
if (node.is('element')) {
this.handleNodes(node.getChildren());
}
}
/**
* Append a node to the temporary ModelDocumentFragment.
*
* @param node The node to insert.
*/
_appendToFragment(node) {
/* istanbul ignore if -- @preserve */
if (!this.schema.checkChild(this.position, node)) {
// Algorithm's correctness check. We should never end up here but it's good to know that we did.
// Note that it would often be a silent issue if we insert node in a place where it's not allowed.
/**
* Given node cannot be inserted on the given position.
*
* @error insertcontent-wrong-position
* @param {module:engine/model/node~ModelNode} node Node to insert.
* @param {module:engine/model/position~ModelPosition} position Position to insert the node at.
*/
throw new CKEditorError('insertcontent-wrong-position', this, { node, position: this.position });
}
this.writer.insert(node, this._documentFragmentPosition);
this._documentFragmentPosition = this._documentFragmentPosition.getShiftedBy(node.offsetSize);
// The last inserted object should be selected because we can't put a collapsed selection after it.
if (this.schema.isObject(node) && !this.schema.checkChild(this.position, '$text')) {
this._nodeToSelect = node;
}
else {
this._nodeToSelect = null;
}
this._filterAttributesOf.push(node);
}
/**
* Sets `_affectedStart` and `_affectedEnd` to the given `position`. Should be used before a change is done during insertion process to
* mark the affected range.
*
* This method is used before inserting a node or splitting a parent node. `_affectedStart` and `_affectedEnd` are also changed
* during merging, but the logic there is more complicated so it is left out of this function.
*/
_setAffectedBoundaries(position) {
// Set affected boundaries stickiness so that those position will "expand" when something is inserted in between them:
// <paragraph>Foo][bar</paragraph> -> <paragraph>Foo]xx[bar</paragraph>
// This is why it cannot be a range but two separate positions.
if (!this._affectedStart) {
this._affectedStart = ModelLivePosition.fromPosition(position, 'toPrevious');
}
// If `_affectedEnd` is before the new boundary position, expand `_affectedEnd`. This can happen if first inserted node was
// inserted into the parent but the next node is moved-out of that parent:
// (1) <paragraph>Foo][</paragraph> -> <paragraph>Foo]xx[</paragraph>
// (2) <paragraph>Foo]xx[</paragraph> -> <paragraph>Foo]xx</paragraph><widget></widget>[
if (!this._affectedEnd || this._affectedEnd.isBefore(position)) {
if (this._affectedEnd) {
this._affectedEnd.detach();
}
this._affectedEnd = ModelLivePosition.fromPosition(position, 'toNext');
}
}
/**
* Merges the previous sibling of the first node if it should be merged.
*
* After the content was inserted we may try to merge it with its siblings.
* This should happen only if the selection was in those elements initially.
*/
_mergeOnLeft() {
const node = this._firstNode;
if (!(node instanceof ModelElement)) {
return;
}
if (!this._canMergeLeft(node)) {
return;
}
const mergePosLeft = ModelLivePosition._createBefore(node);
mergePosLeft.stickiness = 'toNext';
const livePosition = ModelLivePosition.fromPosition(this.position, 'toNext');
// If `_affectedStart` is sames as merge position, it means that the element "marked" by `_affectedStart` is going to be
// removed and its contents will be moved. This won't transform `ModelLivePosition` so `_affectedStart` needs to be moved
// by hand to properly reflect affected range. (Due to `_affectedStart` and `_affectedEnd` stickiness, the "range" is
// shown as `][`).
//
// Example - insert `<paragraph>Abc</paragraph><paragraph>Xyz</paragraph>` at the end of `<paragraph>Foo^</paragraph>`:
//
// <paragraph>Foo</paragraph><paragraph>Bar</paragraph> -->
// <paragraph>Foo</paragraph>]<paragraph>Abc</paragraph><paragraph>Xyz</paragraph>[<paragraph>Bar</paragraph> -->
// <paragraph>Foo]Abc</paragraph><paragraph>Xyz</paragraph>[<paragraph>Bar</paragraph>
//
// Note, that if we are here then something must have been inserted, so `_affectedStart` and `_affectedEnd` have to be set.
if (this._affectedStart.isEqual(mergePosLeft)) {
this._affectedStart.detach();
this._affectedStart = ModelLivePosition._createAt(mergePosLeft.nodeBefore, 'end', 'toPrevious');
}
// We need to update the references to the first and last nodes if they will be merged into the previous sibling node
// because the reference would point to the removed node.
//
// <p>A^A</p> + <p>X</p>
//
// <p>A</p>^<p>A</p>
// <p>A</p><p>X</p><p>A</p>
// <p>AX</p><p>A</p>
// <p>AXA</p>
if (this._firstNode === this._lastNode) {
this._firstNode = mergePosLeft.nodeBefore;
this._lastNode = mergePosLeft.nodeBefore;
}
this.writer.merge(mergePosLeft);
// If only one element (the merged one) is in the "affected range", also move the affected range end appropriately.
//
// Example - insert `<paragraph>Abc</paragraph>` at the of `<paragraph>Foo^</paragraph>`:
//
// <paragraph>Foo</paragraph><paragraph>Bar</paragraph> -->
// <paragraph>Foo</paragraph>]<paragraph>Abc</paragraph>[<paragraph>Bar</paragraph> -->
// <paragraph>Foo]Abc</paragraph>[<paragraph>Bar</paragraph> -->
// <paragraph>Foo]Abc[</paragraph><paragraph>Bar</paragraph>
if (mergePosLeft.isEqual(this._affectedEnd) && this._firstNode === this._lastNode) {
this._affectedEnd.detach();
this._affectedEnd = ModelLivePosition._createAt(mergePosLeft.nodeBefore, 'end', 'toNext');
}
this.position = livePosition.toPosition();
livePosition.detach();
// After merge elements that were marked by _insert() to be filtered might be gone so
// we need to mark the new container.
this._filterAttributesOf.push(this.position.parent);
mergePosLeft.detach();
}
/**
* Merges the next sibling of the last node if it should be merged.
*
* After the content was inserted we may try to merge it with its siblings.
* This should happen only if the selection was in those elements initially.
*/
_mergeOnRight() {
const node = this._lastNode;
if (!(node instanceof ModelElement)) {
return;
}
if (!this._canMergeRight(node)) {
return;
}
const mergePosRight = ModelLivePosition._createAfter(node);
mergePosRight.stickiness = 'toNext';
/* istanbul ignore if -- @preserve */
if (!this.position.isEqual(mergePosRight)) {
// Algorithm's correctness check. We should never end up here but it's good to know that we did.
// At this point the insertion position should be after the node we'll merge. If it isn't,
// it should need to be secured as in the left merge case.
/**
* An internal error occurred when merging inserted content with its siblings.
* The insertion position should equal the merge position.
*
* If you encountered this error, report it back to the CKEditor 5 team
* with as many details as possible regarding the content being inserted and the insertion position.
*
* @error insertcontent-invalid-insertion-position
*/
throw new CKEditorError('insertcontent-invalid-insertion-position', this);
}
// Move the position to the previous node, so it isn't moved to the graveyard on merge.
// <p>x</p>[]<p>y</p> => <p>x[]</p><p>y</p>
this.position = ModelPosition._createAt(mergePosRight.nodeBefore, 'end');
// Explanation of setting position stickiness to `'toPrevious'`:
// OK: <p>xx[]</p> + <p>yy</p> => <p>xx[]yy</p> (when sticks to previous)
// NOK: <p>xx[]</p> + <p>yy</p> => <p>xxyy[]</p> (when sticks to next)
const livePosition = ModelLivePosition.fromPosition(this.position, 'toPrevious');
// See comment in `_mergeOnLeft()` on moving `_affectedStart`.
if (this._affectedEnd.isEqual(mergePosRight)) {
this._affectedEnd.detach();
this._affectedEnd = ModelLivePosition._createAt(mergePosRight.nodeBefore, 'end', 'toNext');
}
// We need to update the references to the first and last nodes if they will be merged into the previous sibling node
// because the reference would point to the removed node.
//
// <p>A^A</p> + <p>X</p>
//
// <p>A</p>^<p>A</p>
// <p>A</p><p>X</p><p>A</p>
// <p>AX</p><p>A</p>
// <p>AXA</p>
if (this._firstNode === this._lastNode) {
this._firstNode = mergePosRight.nodeBefore;
this._lastNode = mergePosRight.nodeBefore;
}
this.writer.merge(mergePosRight);
// See comment in `_mergeOnLeft()` on moving `_affectedStart`.
if (mergePosRight.getShiftedBy(-1).isEqual(this._affectedStart) && this._firstNode === this._lastNode) {
this._affectedStart.detach();
this._affectedStart = ModelLivePosition._createAt(mergePosRight.nodeBefore, 0, 'toPrevious');
}
this.position = livePosition.toPosition();
livePosition.detach();
// After merge elements that were marked by _insert() to be filtered might be gone so
// we need to mark the new container.
this._filterAttributesOf.push(this.position.parent);
mergePosRight.detach();
}
/**
* Checks whether specified node can be merged with previous sibling element.
*
* @param node The node which could potentially be merged.
*/
_canMergeLeft(node) {
const previousSibling = node.previousSibling;
return (previousSibling instanceof ModelElement) &&
this.canMergeWith.has(previousSibling) &&
this.model.schema.checkMerge(previousSibling, node);
}
/**
* Checks whether specified node can be merged with next sibling element.
*
* @param node The node which could potentially be merged.
*/
_canMergeRight(node) {
const nextSibling = node.nextSibling;
return (nextSibling instanceof ModelElement) &&
this.canMergeWith.has(nextSibling) &&
this.model.schema.checkMerge(node, nextSibling);
}
/**
* Inserts a paragraph and moves the insertion position into it.
*/
_insertAutoParagraph() {
// Insert nodes collected in temporary ModelDocumentFragment if the position parent needs change to process further nodes.
this._insertPartialFragment();
// Insert a paragraph and move insertion position to it.
const paragraph = this.writer.createElement('paragraph');
this.writer.insert(paragraph, this.position);
this._setAffectedBoundaries(this.position);
this._lastAutoParagraph = paragraph;
this.position = this.writer.createPositionAt(paragraph, 0);
}
/**
* @returns Whether an allowed position was found.
* `false` is returned if the node isn't allowed at any position up in the tree, `true` if was.
*/
_checkAndSplitToAllowedPosition(node) {
const allowedIn = this._getAllowedIn(this.position.parent, node);
if (!allowedIn) {
return false;
}
// Insert nodes collected in temporary ModelDocumentFragment if the position parent needs change to process further nodes.
if (allowedIn != this.position.parent) {
this._insertPartialFragment();
}
while (allowedIn != this.position.parent) {
if (this.position.isAtStart) {
// If insertion position is at the beginning of the parent, move it out instead of splitting.
// <p>^Foo</p> -> ^<p>Foo</p>
const parent = this.position.parent;
this.position = this.writer.createPositionBefore(parent);
// Special case – parent is empty (<p>^</p>).
//
// 1. parent.isEmpty
// We can remove the element after moving insertion position out of it.
//
// 2. parent.parent === allowedIn
// However parent should remain in place when allowed element is above limit element in document tree.
// For example there shouldn't be allowed to remove empty paragraph from tableCell, when is pasted
// content allowed in $root.
if (parent.isEmpty && parent.parent === allowedIn) {
this.writer.remove(parent);
}
}
else if (this.position.isAtEnd) {
// If insertion position is at the end of the parent, move it out instead of splitting.
// <p>Foo^</p> -> <p>Foo</p>^
this.position = this.writer.createPositionAfter(this.position.parent);
}
else {
const tempPos = this.writer.createPositionAfter(this.position.parent);
this._setAffectedBoundaries(this.position);
this.writer.split(this.position);
this.position = tempPos;
this.canMergeWith.add(this.position.nodeAfter);
}
}
// At this point, we split elements up to the parent in which `node` is allowed.
// Note that `_getAllowedIn()` checks if the `node` is allowed either directly, or when auto-paragraphed.
// So, let's check if the `node` is allowed directly. If not, we need to auto-paragraph it.
if (!this.schema.checkChild(this.position.parent, node)) {
this._insertAutoParagraph();
}
return true;
}
/**
* Gets the element in which the given node is allowed. It checks the passed element and all its ancestors.
*
* It also verifies if auto-paragraphing could help.
*
* @param contextElement The element in which context the node should be checked.
* @param childNode The node to check.
*/
_getAllowedIn(contextElement, childNode) {
// Check if a node can be inserted in the given context...
if (this.schema.checkChild(contextElement, childNode)) {
return contextElement;
}
// ...or it would be accepted if a paragraph would be inserted.
if (this.schema.checkChild(contextElement, 'paragraph') && this.schema.checkChild('paragraph', childNode)) {
return contextElement;
}
// If the child wasn't allowed in the context element and the element is a limit there's no point in
// checking any further towards the root. This is it: the limit is unsplittable and there's nothing
// we can do about it. Without this check, the algorithm will analyze parent of the limit and may create
// an illusion of the child being allowed. There's no way to insert it down there, though. It results in
// infinite loops.
if (this.schema.isLimit(contextElement)) {
return null;
}
return this._getAllowedIn(contextElement.parent, childNode);
}
}