ckeditor5-image-upload-base64
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The development environment of CKEditor 5 – the best browser-based rich text editor.
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JavaScript
/**
* @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 engine/model/utils/deletecontent
*/
import LivePosition from '../liveposition';
import Range from '../range';
import DocumentSelection from '../documentselection';
/**
* Deletes content of the selection and merge siblings. The resulting selection is always collapsed.
*
* **Note:** Use {@link module:engine/model/model~Model#deleteContent} instead of this function.
* This function is only exposed to be reusable in algorithms
* which change the {@link module:engine/model/model~Model#deleteContent}
* method's behavior.
*
* @param {module:engine/model/model~Model} model The model in context of which the insertion
* should be performed.
* @param {module:engine/model/selection~Selection|module:engine/model/documentselection~DocumentSelection} selection
* Selection of which the content should be deleted.
* @param {Object} [options]
* @param {Boolean} [options.leaveUnmerged=false] Whether to merge elements after removing the content of the selection.
*
* For example `<heading>x[x</heading><paragraph>y]y</paragraph>` will become:
*
* * `<heading>x^y</heading>` with the option disabled (`leaveUnmerged == false`)
* * `<heading>x^</heading><paragraph>y</paragraph>` with enabled (`leaveUnmerged == true`).
*
* Note: {@link module:engine/model/schema~Schema#isObject object} and {@link module:engine/model/schema~Schema#isLimit limit}
* elements will not be merged.
*
* @param {Boolean} [options.doNotResetEntireContent=false] Whether to skip replacing the entire content with a
* paragraph when the entire content was selected.
*
* For example `<heading>[x</heading><paragraph>y]</paragraph>` will become:
*
* * `<paragraph>^</paragraph>` with the option disabled (`doNotResetEntireContent == false`)
* * `<heading>^</heading>` with enabled (`doNotResetEntireContent == true`).
*
* @param {Boolean} [options.doNotAutoparagraph=false] Whether to create a paragraph if after content deletion selection is moved
* to a place where text cannot be inserted.
*
* For example `<paragraph>x</paragraph>[<image src="foo.jpg"></image>]` will become:
*
* * `<paragraph>x</paragraph><paragraph>[]</paragraph>` with the option disabled (`doNotAutoparagraph == false`)
* * `<paragraph>x</paragraph>[]` with the option enabled (`doNotAutoparagraph == true`).
*
* If you use this option you need to make sure to handle invalid selections yourself or leave
* them to the selection post-fixer (may not always work).
*
* **Note:** if there is no valid position for the selection, the paragraph will always be created:
*
* `[<image src="foo.jpg"></image>]` -> `<paragraph>[]</paragraph>`.
*/
export default function deleteContent( model, selection, options = {} ) {
if ( selection.isCollapsed ) {
return;
}
const selRange = selection.getFirstRange();
// If the selection is already removed, don't do anything.
if ( selRange.root.rootName == '$graveyard' ) {
return;
}
const schema = model.schema;
model.change( writer => {
// 1. Replace the entire content with paragraph.
// See: https://github.com/ckeditor/ckeditor5-engine/issues/1012#issuecomment-315017594.
if ( !options.doNotResetEntireContent && shouldEntireContentBeReplacedWithParagraph( schema, selection ) ) {
replaceEntireContentWithParagraph( writer, selection, schema );
return;
}
// Get the live positions for the range adjusted to span only blocks selected from the user perspective.
const [ startPosition, endPosition ] = getLivePositionsForSelectedBlocks( selRange );
// 2. Remove the content if there is any.
if ( !selRange.start.isTouching( selRange.end ) ) {
writer.remove( selRange );
}
// 3. Merge elements in the right branch to the elements in the left branch.
// The only reasonable (in terms of data and selection correctness) case in which we need to do that is:
//
// <heading type=1>Fo[</heading><paragraph>]ar</paragraph> => <heading type=1>Fo^ar</heading>
//
// However, the algorithm supports also merging deeper structures (up to the depth of the shallower branch),
// as it's hard to imagine what should actually be the default behavior. Usually, specific features will
// want to override that behavior anyway.
if ( !options.leaveUnmerged ) {
mergeBranches( writer, startPosition, endPosition );
// TMP this will be replaced with a postfixer.
// We need to check and strip disallowed attributes in all nested nodes because after merge
// some attributes could end up in a path where are disallowed.
//
// e.g. bold is disallowed for <H1>
// <h1>Fo{o</h1><p>b}a<b>r</b><p> -> <h1>Fo{}a<b>r</b><h1> -> <h1>Fo{}ar<h1>.
schema.removeDisallowedAttributes( startPosition.parent.getChildren(), writer );
}
collapseSelectionAt( writer, selection, startPosition );
// 4. Add a paragraph to set selection in it.
// Check if a text is allowed in the new container. If not, try to create a new paragraph (if it's allowed here).
// If autoparagraphing is off, we assume that you know what you do so we leave the selection wherever it was.
if ( !options.doNotAutoparagraph && shouldAutoparagraph( schema, startPosition ) ) {
insertParagraph( writer, startPosition, selection );
}
startPosition.detach();
endPosition.detach();
} );
}
// Returns the live positions for the range adjusted to span only blocks selected from the user perspective. Example:
//
// <heading1>[foo</heading1>
// <paragraph>bar</paragraph>
// <heading1>]abc</heading1> <-- this block is not considered as selected
//
// This is the same behavior as in Selection#getSelectedBlocks() "special case".
function getLivePositionsForSelectedBlocks( range ) {
const model = range.root.document.model;
const startPosition = range.start;
let endPosition = range.end;
// If the end of selection is at the start position of last block in the selection, then
// shrink it to not include that trailing block. Note that this should happen only for not empty selection.
if ( model.hasContent( range, { ignoreMarkers: true } ) ) {
const endBlock = getParentBlock( endPosition );
if ( endBlock && endPosition.isTouching( model.createPositionAt( endBlock, 0 ) ) ) {
// Create forward selection as a probe to find a valid position after excluding last block from the range.
const selection = model.createSelection( range );
// Modify the forward selection in backward direction to shrink it and remove first position of following block from it.
// This is how modifySelection works and here we are making use of it.
model.modifySelection( selection, { direction: 'backward' } );
endPosition = selection.getLastPosition();
}
}
return [
LivePosition.fromPosition( startPosition, 'toPrevious' ),
LivePosition.fromPosition( endPosition, 'toNext' )
];
}
// Finds the lowest element in position's ancestors which is a block.
// Returns null if a limit element is encountered before reaching a block element.
function getParentBlock( position ) {
const element = position.parent;
const schema = element.root.document.model.schema;
const ancestors = element.getAncestors( { parentFirst: true, includeSelf: true } );
for ( const element of ancestors ) {
if ( schema.isLimit( element ) ) {
return null;
}
if ( schema.isBlock( element ) ) {
return element;
}
}
}
// This function is a result of reaching the Ballmer's peak for just the right amount of time.
// Even I had troubles documenting it after a while and after reading it again I couldn't believe that it really works.
function mergeBranches( writer, startPosition, endPosition ) {
const model = writer.model;
// Verify if there is a need and possibility to merge.
if ( !checkShouldMerge( writer.model.schema, startPosition, endPosition ) ) {
return;
}
// If the start element on the common ancestor level is empty, and the end element on the same level is not empty
// then merge those to the right element so that it's properties are preserved (name, attributes).
// Because of OT merging is used instead of removing elements.
//
// Merge left:
// <heading1>foo[</heading1> -> <heading1>foo[]bar</heading1>
// <paragraph>]bar</paragraph> -> --^
//
// Merge right:
// <heading1>[</heading1> ->
// <paragraph>]bar</paragraph> -> <paragraph>[]bar</paragraph>
//
// Merge left:
// <blockQuote> -> <blockQuote>
// <heading1>foo[</heading1> -> <heading1>foo[]bar</heading1>
// <paragraph>]bar</paragraph> -> --^
// </blockQuote> -> </blockQuote>
//
// Merge right:
// <blockQuote> -> <blockQuote>
// <heading1>[</heading1> ->
// <paragraph>]bar</paragraph> -> <paragraph>[]bar</paragraph>
// </blockQuote> -> </blockQuote>
// Merging should not go deeper than common ancestor.
const [ startAncestor, endAncestor ] = getAncestorsJustBelowCommonAncestor( startPosition, endPosition );
if ( !model.hasContent( startAncestor, { ignoreMarkers: true } ) && model.hasContent( endAncestor, { ignoreMarkers: true } ) ) {
mergeBranchesRight( writer, startPosition, endPosition, startAncestor.parent );
} else {
mergeBranchesLeft( writer, startPosition, endPosition, startAncestor.parent );
}
}
// Merging blocks to the left (properties of the left block are preserved).
// Simple example:
// <heading1>foo[</heading1> -> <heading1>foo[bar</heading1>]
// <paragraph>]bar</paragraph> -> --^
//
// Nested example:
// <blockQuote> -> <blockQuote>
// <heading1>foo[</heading1> -> <heading1>foo[bar</heading1>
// </blockQuote> -> </blockQuote>] ^
// <blockBlock> -> |
// <paragraph>]bar</paragraph> -> ---
// </blockBlock> ->
//
function mergeBranchesLeft( writer, startPosition, endPosition, commonAncestor ) {
const startElement = startPosition.parent;
const endElement = endPosition.parent;
// Merging reached the common ancestor element, stop here.
if ( startElement == commonAncestor || endElement == commonAncestor ) {
return;
}
// Remember next positions to merge in next recursive step (also used as modification points pointers).
startPosition = writer.createPositionAfter( startElement );
endPosition = writer.createPositionBefore( endElement );
// Move endElement just after startElement if they aren't siblings.
if ( !endPosition.isEqual( startPosition ) ) {
//
// <blockQuote> -> <blockQuote>
// <heading1>foo[</heading1> -> <heading1>foo</heading1>[<paragraph>bar</paragraph>
// </blockQuote> -> </blockQuote> ^
// <blockBlock> -> <blockBlock> |
// <paragraph>]bar</paragraph> -> ] ---
// </blockBlock> -> </blockBlock>
//
writer.insert( endElement, startPosition );
}
// Merge two siblings (nodes on sides of startPosition):
//
// <blockQuote> -> <blockQuote>
// <heading1>foo</heading1>[<paragraph>bar</paragraph> -> <heading1>foo[bar</heading1>
// </blockQuote> -> </blockQuote>
// <blockBlock> -> <blockBlock>
// ] -> ]
// </blockBlock> -> </blockBlock>
//
// Or in simple case (without moving elements in above if):
// <heading1>foo</heading1>[<paragraph>bar</paragraph>] -> <heading1>foo[bar</heading1>]
//
writer.merge( startPosition );
// Remove empty end ancestors:
//
// <blockQuote> -> <blockQuote>
// <heading1>foo[bar</heading1> -> <heading1>foo[bar</heading1>
// </blockQuote> -> </blockQuote>
// <blockBlock> ->
// ] -> ]
// </blockBlock> ->
//
while ( endPosition.parent.isEmpty ) {
const parentToRemove = endPosition.parent;
endPosition = writer.createPositionBefore( parentToRemove );
writer.remove( parentToRemove );
}
// Verify if there is a need and possibility to merge next level.
if ( !checkShouldMerge( writer.model.schema, startPosition, endPosition ) ) {
return;
}
// Continue merging next level (blockQuote with blockBlock in the examples above if it would not be empty and got removed).
mergeBranchesLeft( writer, startPosition, endPosition, commonAncestor );
}
// Merging blocks to the right (properties of the right block are preserved).
// Simple example:
// <heading1>foo[</heading1> -> --v
// <paragraph>]bar</paragraph> -> [<paragraph>foo]bar</paragraph>
//
// Nested example:
// <blockQuote> ->
// <heading1>foo[</heading1> -> ---
// </blockQuote> -> |
// <blockBlock> -> [<blockBlock> v
// <paragraph>]bar</paragraph> -> <paragraph>foo]bar</paragraph>
// </blockBlock> -> </blockBlock>
//
function mergeBranchesRight( writer, startPosition, endPosition, commonAncestor ) {
const startElement = startPosition.parent;
const endElement = endPosition.parent;
// Merging reached the common ancestor element, stop here.
if ( startElement == commonAncestor || endElement == commonAncestor ) {
return;
}
// Remember next positions to merge in next recursive step (also used as modification points pointers).
startPosition = writer.createPositionAfter( startElement );
endPosition = writer.createPositionBefore( endElement );
// Move startElement just before endElement if they aren't siblings.
if ( !endPosition.isEqual( startPosition ) ) {
//
// <blockQuote> -> <blockQuote>
// <heading1>foo[</heading1> -> [ ---
// </blockQuote> -> </blockQuote> |
// <blockBlock> -> <blockBlock> v
// <paragraph>]bar</paragraph> -> <heading1>foo</heading1>]<paragraph>bar</paragraph>
// </blockBlock> -> </blockBlock>
//
writer.insert( startElement, endPosition );
}
// Remove empty end ancestors:
//
// <blockQuote> ->
// [ -> [
// </blockQuote> ->
// <blockBlock> -> <blockBlock>
// <heading1>foo</heading1>]<paragraph>bar</paragraph> -> <heading1>foo</heading1>]<paragraph>bar</paragraph>
// </blockBlock> -> </blockBlock>
//
while ( startPosition.parent.isEmpty ) {
const parentToRemove = startPosition.parent;
startPosition = writer.createPositionBefore( parentToRemove );
writer.remove( parentToRemove );
}
// Update endPosition after inserting and removing elements.
endPosition = writer.createPositionBefore( endElement );
// Merge right two siblings (nodes on sides of endPosition):
// ->
// [ -> [
// ->
// <blockBlock> -> <blockBlock>
// <heading1>foo</heading1>]<paragraph>bar</paragraph> -> <paragraph>foo]bar</paragraph>
// </blockBlock> -> </blockBlock>
//
// Or in simple case (without moving elements in above if):
// [<heading1>foo</heading1>]<paragraph>bar</paragraph> -> [<heading1>foo]bar</heading1>
//
mergeRight( writer, endPosition );
// Verify if there is a need and possibility to merge next level.
if ( !checkShouldMerge( writer.model.schema, startPosition, endPosition ) ) {
return;
}
// Continue merging next level (blockQuote with blockBlock in the examples above if it would not be empty and got removed).
mergeBranchesRight( writer, startPosition, endPosition, commonAncestor );
}
// There is no right merge operation so we need to simulate it.
function mergeRight( writer, position ) {
const startElement = position.nodeBefore;
const endElement = position.nodeAfter;
if ( startElement.name != endElement.name ) {
writer.rename( startElement, endElement.name );
}
writer.clearAttributes( startElement );
writer.setAttributes( Object.fromEntries( endElement.getAttributes() ), startElement );
writer.merge( position );
}
// Verifies if merging is needed and possible. It's not needed if both positions are in the same element
// and it's not possible if some element is a limit or the range crosses a limit element.
function checkShouldMerge( schema, startPosition, endPosition ) {
const startElement = startPosition.parent;
const endElement = endPosition.parent;
// If both positions ended up in the same parent, then there's nothing more to merge:
// <$root><p>x[</p><p>]y</p></$root> => <$root><p>xy</p>[]</$root>
if ( startElement == endElement ) {
return false;
}
// If one of the positions is a limit element, then there's nothing to merge because we don't want to cross the limit boundaries.
if ( schema.isLimit( startElement ) || schema.isLimit( endElement ) ) {
return false;
}
// Check if operations we'll need to do won't need to cross object or limit boundaries.
// E.g., we can't merge endElement into startElement in this case:
// <limit><startElement>x[</startElement></limit><endElement>]</endElement>
return isCrossingLimitElement( startPosition, endPosition, schema );
}
// Returns the elements that are the ancestors of the provided positions that are direct children of the common ancestor.
function getAncestorsJustBelowCommonAncestor( positionA, positionB ) {
const ancestorsA = positionA.getAncestors();
const ancestorsB = positionB.getAncestors();
let i = 0;
while ( ancestorsA[ i ] && ancestorsA[ i ] == ancestorsB[ i ] ) {
i++;
}
return [ ancestorsA[ i ], ancestorsB[ i ] ];
}
function shouldAutoparagraph( schema, position ) {
const isTextAllowed = schema.checkChild( position, '$text' );
const isParagraphAllowed = schema.checkChild( position, 'paragraph' );
return !isTextAllowed && isParagraphAllowed;
}
// Check if parents of two positions can be merged by checking if there are no limit/object
// boundaries between those two positions.
//
// E.g. in <bQ><p>x[]</p></bQ><widget><caption>{}</caption></widget>
// we'll check <p>, <bQ>, <widget> and <caption>.
// Usually, widget and caption are marked as objects/limits in the schema, so in this case merging will be blocked.
function isCrossingLimitElement( leftPos, rightPos, schema ) {
const rangeToCheck = new Range( leftPos, rightPos );
for ( const value of rangeToCheck.getWalker() ) {
if ( schema.isLimit( value.item ) ) {
return false;
}
}
return true;
}
function insertParagraph( writer, position, selection ) {
const paragraph = writer.createElement( 'paragraph' );
writer.insert( paragraph, position );
collapseSelectionAt( writer, selection, writer.createPositionAt( paragraph, 0 ) );
}
function replaceEntireContentWithParagraph( writer, selection ) {
const limitElement = writer.model.schema.getLimitElement( selection );
writer.remove( writer.createRangeIn( limitElement ) );
insertParagraph( writer, writer.createPositionAt( limitElement, 0 ), selection );
}
// We want to replace the entire content with a paragraph when:
// * the entire content is selected,
// * selection contains at least two elements,
// * whether the paragraph is allowed in schema in the common ancestor.
function shouldEntireContentBeReplacedWithParagraph( schema, selection ) {
const limitElement = schema.getLimitElement( selection );
if ( !selection.containsEntireContent( limitElement ) ) {
return false;
}
const range = selection.getFirstRange();
if ( range.start.parent == range.end.parent ) {
return false;
}
return schema.checkChild( limitElement, 'paragraph' );
}
// Helper function that sets the selection. Depending whether given `selection` is a document selection or not,
// uses a different method to set it.
function collapseSelectionAt( writer, selection, positionOrRange ) {
if ( selection instanceof DocumentSelection ) {
writer.setSelection( positionOrRange );
} else {
selection.setTo( positionOrRange );
}
}