ckeditor/ckeditor5-engine

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src/view/upcastwriter.js

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/**
 * @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 module:engine/view/upcastwriter
 */

import DocumentFragment from './documentfragment';
import Element from './element';
import Text from './text';
import { isPlainObject } from 'lodash-es';
import Position from './position';
import Range from './range';
import Selection from './selection';

/**
 * View upcast writer. It provides a set of methods used to manipulate non-semantic view trees.
 *
 * It should be used only while working on a non-semantic view
 * (e.g. a view created from HTML string on paste).
 * To manipulate a view which was or is being downcasted from the the model use the
 * {@link module:engine/view/downcastwriter~DowncastWriter downcast writer}.
 *
 * Read more about changing the view in the {@glink framework/guides/architecture/editing-engine#changing-the-view Changing the view}
 * section of the {@glink framework/guides/architecture/editing-engine Editing engine architecture} guide.
 *
 * Unlike `DowncastWriter`, which is available in the {@link module:engine/view/view~View#change `View#change()`} block,
 * `UpcastWriter` can be created wherever you need it:
 *
 *        const writer = new UpcastWriter( viewDocument );
 *        const text = writer.createText( 'foo!' );
 *
 *        writer.appendChild( text, someViewElement );
 */
export default class UpcastWriter {
    /**
     * @param {module:engine/view/document~Document} document The view document instance in which this upcast writer operates.
     */
    constructor( document ) {
        /**
         * The view document instance in which this upcast writer operates.
         *
         * @readonly
         * @type {module:engine/view/document~Document}
         */
        this.document = document;
    }

    /**
     * Creates a new {@link module:engine/view/documentfragment~DocumentFragment} instance.
     *
     * @param {module:engine/view/node~Node|Iterable.<module:engine/view/node~Node>} [children]
     * A list of nodes to be inserted into the created document fragment.
     * @returns {module:engine/view/documentfragment~DocumentFragment} The created document fragment.
     */
    createDocumentFragment( children ) {
        return new DocumentFragment( this.document, children );
    }

    /**
     * Creates a new {@link module:engine/view/element~Element} instance.
     *
     * Attributes can be passed in various formats:
     *
     *        upcastWriter.createElement( 'div', { class: 'editor', contentEditable: 'true' } ); // object
     *        upcastWriter.createElement( 'div', [ [ 'class', 'editor' ], [ 'contentEditable', 'true' ] ] ); // map-like iterator
     *        upcastWriter.createElement( 'div', mapOfAttributes ); // map
     *
     * @param {String} name Node name.
     * @param {Object|Iterable} [attrs] Collection of attributes.
     * @param {module:engine/view/node~Node|Iterable.<module:engine/view/node~Node>} [children]
     * A list of nodes to be inserted into created element.
     * @returns {module:engine/view/element~Element} Created element.
     */
    createElement( name, attrs, children ) {
        return new Element( this.document, name, attrs, children );
    }

    /**
     * Creates a new {@link module:engine/view/text~Text} instance.
     *
     * @param {String} data The text's data.
     * @returns {module:engine/view/text~Text} The created text node.
     */
    createText( data ) {
        return new Text( this.document, data );
    }

    /**
     * Clones the provided element.
     *
     * @see module:engine/view/element~Element#_clone
     * @param {module:engine/view/element~Element} element Element to be cloned.
     * @param {Boolean} [deep=false] If set to `true` clones element and all its children recursively. When set to `false`,
     * element will be cloned without any children.
     * @returns {module:engine/view/element~Element} Clone of this element.
     */
    clone( element, deep = false ) {
        return element._clone( deep );
    }

    /**
     * Appends a child node or a list of child nodes at the end of this node
     * and sets the parent of these nodes to this element.
     *
     * @see module:engine/view/element~Element#_appendChild
     * @param {module:engine/view/item~Item|Iterable.<module:engine/view/item~Item>} items Items to be inserted.
     * @param {module:engine/view/element~Element|module:engine/view/documentfragment~DocumentFragment} element Element
     * to which items will be appended.
     * @fires module:engine/view/node~Node#event:change
     * @returns {Number} Number of appended nodes.
     */
    appendChild( items, element ) {
        return element._appendChild( items );
    }

    /**
     * Inserts a child node or a list of child nodes on the given index and sets the parent of these nodes to
     * this element.
     *
     * @see module:engine/view/element~Element#_insertChild
     * @param {Number} index Offset at which nodes should be inserted.
     * @param {module:engine/view/item~Item|Iterable.<module:engine/view/item~Item>} items Items to be inserted.
     * @param {module:engine/view/element~Element|module:engine/view/documentfragment~DocumentFragment} element Element
     * to which items will be inserted.
     * @fires module:engine/view/node~Node#event:change
     * @returns {Number} Number of inserted nodes.
     */
    insertChild( index, items, element ) {
        return element._insertChild( index, items );
    }

    /**
     * Removes the given number of child nodes starting at the given index and set the parent of these nodes to `null`.
     *
     * @see module:engine/view/element~Element#_removeChildren
     * @param {Number} index Offset from which nodes will be removed.
     * @param {Number} howMany Number of nodes to remove.
     * @param {module:engine/view/element~Element|module:engine/view/documentfragment~DocumentFragment} element Element
     * which children will be removed.
     * @fires module:engine/view/node~Node#event:change
     * @returns {Array.<module:engine/view/node~Node>} The array containing removed nodes.
     */
    removeChildren( index, howMany, element ) {
        return element._removeChildren( index, howMany );
    }

    /**
     * Removes given element from the view structure. Will not have effect on detached elements.
     *
     * @param {module:engine/view/element~Element} element Element which will be removed.
     * @returns {Array.<module:engine/view/node~Node>} The array containing removed nodes.
     */
    remove( element ) {
        const parent = element.parent;

        if ( parent ) {
            return this.removeChildren( parent.getChildIndex( element ), 1, parent );
        }

        return [];
    }

    /**
     * Replaces given element with the new one in the view structure. Will not have effect on detached elements.
     *
     * @param {module:engine/view/element~Element} oldElement Element which will be replaced.
     * @param {module:engine/view/element~Element} newElement Element which will be inserted in the place of the old element.
     * @returns {Boolean} Whether old element was successfully replaced.
     */
    replace( oldElement, newElement ) {
        const parent = oldElement.parent;

        if ( parent ) {
            const index = parent.getChildIndex( oldElement );

            this.removeChildren( index, 1, parent );
            this.insertChild( index, newElement, parent );

            return true;
        }

        return false;
    }

    /**
     * Removes given element from view structure and places its children in its position.
     * It does nothing if element has no parent.
     *
     * @param {module:engine/view/element~Element} element Element to unwrap.
     */
    unwrapElement( element ) {
        const parent = element.parent;

        if ( parent ) {
            const index = parent.getChildIndex( element );

            this.remove( element );
            this.insertChild( index, element.getChildren(), parent );
        }
    }

    /**
     * Renames element by creating a copy of a given element but with its name changed and then moving contents of the
     * old element to the new one.
     *
     * Since this function creates a new element and removes the given one, the new element is returned to keep reference.
     *
     * @param {String} newName New element name.
     * @param {module:engine/view/element~Element} element Element to be renamed.
     * @returns {module:engine/view/element~Element|null} New element or null if the old element
     * was not replaced (happens for detached elements).
     */
    rename( newName, element ) {
        const newElement = new Element( this.document, newName, element.getAttributes(), element.getChildren() );

        return this.replace( element, newElement ) ? newElement : null;
    }

    /**
     * Adds or overwrites element's attribute with a specified key and value.
     *
     *        writer.setAttribute( linkElement, 'href', 'http://ckeditor.com' );
     *
     * @see module:engine/view/element~Element#_setAttribute
     * @param {String} key Attribute key.
     * @param {String} value Attribute value.
     * @param {module:engine/view/element~Element} element Element for which attribute will be set.
     */
    setAttribute( key, value, element ) {
        element._setAttribute( key, value );
    }

    /**
     * Removes attribute from the element.
     *
     *        writer.removeAttribute( linkElement, 'href' );
     *
     * @see module:engine/view/element~Element#_removeAttribute
     * @param {String} key Attribute key.
     * @param {module:engine/view/element~Element} element Element from which attribute will be removed.
     */
    removeAttribute( key, element ) {
        element._removeAttribute( key );
    }

    /**
     * Adds specified class to the element.
     *
     *        writer.addClass( linkElement, 'foo' );
     *        writer.addClass( linkElement, [ 'foo', 'bar' ] );
     *
     * @see module:engine/view/element~Element#_addClass
     * @param {Array.<String>|String} className Single class name or array of class names which will be added.
     * @param {module:engine/view/element~Element} element Element for which class will be added.
     */
    addClass( className, element ) {
        element._addClass( className );
    }

    /**
     * Removes specified class from the element.
     *
     *        writer.removeClass( linkElement, 'foo' );
     *        writer.removeClass( linkElement, [ 'foo', 'bar' ] );
     *
     * @see module:engine/view/element~Element#_removeClass
     * @param {Array.<String>|String} className Single class name or array of class names which will be removed.
     * @param {module:engine/view/element~Element} element Element from which class will be removed.
     */
    removeClass( className, element ) {
        element._removeClass( className );
    }

    /**
     * Adds style to the element.
     *
     *        writer.setStyle( element, 'color', 'red' );
     *        writer.setStyle( element, {
     *            color: 'red',
     *            position: 'fixed'
     *        } );
     *
     * **Note**: This method can work with normalized style names if
     * {@link module:engine/controller/datacontroller~DataController#addStyleProcessorRules a particular style processor rule is enabled}.
     * See {@link module:engine/view/stylesmap~StylesMap#set `StylesMap#set()`} for details.
     *
     * @see module:engine/view/element~Element#_setStyle
     * @param {String|Object} property Property name or object with key - value pairs.
     * @param {String} [value] Value to set. This parameter is ignored if object is provided as the first parameter.
     * @param {module:engine/view/element~Element} element Element for which style will be added.
     */
    setStyle( property, value, element ) {
        if ( isPlainObject( property ) && element === undefined ) {
            element = value;
        }
        element._setStyle( property, value );
    }

    /**
     * Removes specified style from the element.
     *
     *        writer.removeStyle( element, 'color' );  // Removes 'color' style.
     *        writer.removeStyle( element, [ 'color', 'border-top' ] ); // Removes both 'color' and 'border-top' styles.
     *
     * **Note**: This method can work with normalized style names if
     * {@link module:engine/controller/datacontroller~DataController#addStyleProcessorRules a particular style processor rule is enabled}.
     * See {@link module:engine/view/stylesmap~StylesMap#remove `StylesMap#remove()`} for details.
     *
     * @see module:engine/view/element~Element#_removeStyle
     * @param {Array.<String>|String} property Style property name or names to be removed.
     * @param {module:engine/view/element~Element} element Element from which style will be removed.
     */
    removeStyle( property, element ) {
        element._removeStyle( property );
    }

    /**
     * Sets a custom property on element. Unlike attributes, custom properties are not rendered to the DOM,
     * so they can be used to add special data to elements.
     *
     * @see module:engine/view/element~Element#_setCustomProperty
     * @param {String|Symbol} key Custom property name/key.
     * @param {*} value Custom property value to be stored.
     * @param {module:engine/view/element~Element} element Element for which custom property will be set.
     */
    setCustomProperty( key, value, element ) {
        element._setCustomProperty( key, value );
    }

    /**
     * Removes a custom property stored under the given key.
     *
     * @see module:engine/view/element~Element#_removeCustomProperty
     * @param {String|Symbol} key Name/key of the custom property to be removed.
     * @param {module:engine/view/element~Element} element Element from which the custom property will be removed.
     * @returns {Boolean} Returns true if property was removed.
     */
    removeCustomProperty( key, element ) {
        return element._removeCustomProperty( key );
    }

    /**
     * Creates position at the given location. The location can be specified as:
     *
     * * a {@link module:engine/view/position~Position position},
     * * parent element and offset (offset defaults to `0`),
     * * parent element and `'end'` (sets position at the end of that element),
     * * {@link module:engine/view/item~Item view item} and `'before'` or `'after'` (sets position before or after given view item).
     *
     * This method is a shortcut to other constructors such as:
     *
     * * {@link #createPositionBefore},
     * * {@link #createPositionAfter},
     *
     * @param {module:engine/view/item~Item|module:engine/model/position~Position} itemOrPosition
     * @param {Number|'end'|'before'|'after'} [offset] Offset or one of the flags. Used only when
     * first parameter is a {@link module:engine/view/item~Item view item}.
     */
    createPositionAt( itemOrPosition, offset ) {
        return Position._createAt( itemOrPosition, offset );
    }

    /**
     * Creates a new position after given view item.
     *
     * @param {module:engine/view/item~Item} item View item after which the position should be located.
     * @returns {module:engine/view/position~Position}
     */
    createPositionAfter( item ) {
        return Position._createAfter( item );
    }

    /**
     * Creates a new position before given view item.
     *
     * @param {module:engine/view/item~Item} item View item before which the position should be located.
     * @returns {module:engine/view/position~Position}
     */
    createPositionBefore( item ) {
        return Position._createBefore( item );
    }

    /**
     * Creates a range spanning from `start` position to `end` position.
     *
     * **Note:** This factory method creates it's own {@link module:engine/view/position~Position} instances basing on passed values.
     *
     * @param {module:engine/view/position~Position} start Start position.
     * @param {module:engine/view/position~Position} [end] End position. If not set, range will be collapsed at `start` position.
     * @returns {module:engine/view/range~Range}
     */
    createRange( start, end ) {
        return new Range( start, end );
    }

    /**
     * Creates a range that starts before given {@link module:engine/view/item~Item view item} and ends after it.
     *
     * @param {module:engine/view/item~Item} item
     * @returns {module:engine/view/range~Range}
     */
    createRangeOn( item ) {
        return Range._createOn( item );
    }

    /**
     * Creates a range inside an {@link module:engine/view/element~Element element} which starts before the first child of
     * that element and ends after the last child of that element.
     *
     * @param {module:engine/view/element~Element} element Element which is a parent for the range.
     * @returns {module:engine/view/range~Range}
     */
    createRangeIn( element ) {
        return Range._createIn( element );
    }

    /**
     * Creates a new {@link module:engine/view/selection~Selection} instance.
     *
     *         // Creates empty selection without ranges.
     *        const selection = writer.createSelection();
     *
     *        // Creates selection at the given range.
     *        const range = writer.createRange( start, end );
     *        const selection = writer.createSelection( range );
     *
     *        // Creates selection at the given ranges
     *         const ranges = [ writer.createRange( start1, end2 ), writer.createRange( star2, end2 ) ];
     *        const selection = writer.createSelection( ranges );
     *
     *        // Creates selection from the other selection.
     *        const otherSelection = writer.createSelection();
     *        const selection = writer.createSelection( otherSelection );
     *
     *        // Creates selection from the document selection.
     *        const selection = writer.createSelection( editor.editing.view.document.selection );
     *
     *         // Creates selection at the given position.
     *        const position = writer.createPositionFromPath( root, path );
     *        const selection = writer.createSelection( position );
     *
     *        // Creates collapsed selection at the position of given item and offset.
     *        const paragraph = writer.createContainerElement( 'paragraph' );
     *        const selection = writer.createSelection( paragraph, offset );
     *
     *        // Creates a range inside an {@link module:engine/view/element~Element element} which starts before the
     *        // first child of that element and ends after the last child of that element.
     *        const selection = writer.createSelection( paragraph, 'in' );
     *
     *        // Creates a range on an {@link module:engine/view/item~Item item} which starts before the item and ends
     *        // just after the item.
     *        const selection = writer.createSelection( paragraph, 'on' );
     *
     * `Selection`'s constructor allow passing additional options (`backward`, `fake` and `label`) as the last argument.
     *
     *        // Creates backward selection.
     *        const selection = writer.createSelection( range, { backward: true } );
     *
     * Fake selection does not render as browser native selection over selected elements and is hidden to the user.
     * This way, no native selection UI artifacts are displayed to the user and selection over elements can be
     * represented in other way, for example by applying proper CSS class.
     *
     * Additionally fake's selection label can be provided. It will be used to describe fake selection in DOM
     * (and be  properly handled by screen readers).
     *
     *        // Creates fake selection with label.
     *        const selection = writer.createSelection( range, { fake: true, label: 'foo' } );
     *
     * @param {module:engine/view/selection~Selectable} [selectable=null]
     * @param {Number|'before'|'end'|'after'|'on'|'in'} [placeOrOffset] Offset or place when selectable is an `Item`.
     * @param {Object} [options]
     * @param {Boolean} [options.backward] Sets this selection instance to be backward.
     * @param {Boolean} [options.fake] Sets this selection instance to be marked as `fake`.
     * @param {String} [options.label] Label for the fake selection.
     * @returns {module:engine/view/selection~Selection}
     */
    createSelection( selectable, placeOrOffset, options ) {
        return new Selection( selectable, placeOrOffset, options );
    }
}