ckeditor/ckeditor5-engine

/**
 * @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/operation/insertoperation
 */

import Operation from './operation';
import Position from '../position';
import NodeList from '../nodelist';
import MoveOperation from './moveoperation';
import { _insert, _normalizeNodes } from './utils';
import Text from '../text';
import Element from '../element';
import CKEditorError from '@ckeditor/ckeditor5-utils/src/ckeditorerror';

/**
 * Operation to insert one or more nodes at given position in the model.
 *
 * @extends module:engine/model/operation/operation~Operation
 */
export default class InsertOperation extends Operation {
    /**
     * Creates an insert operation.
     *
     * @param {module:engine/model/position~Position} position Position of insertion.
     * @param {module:engine/model/node~NodeSet} nodes The list of nodes to be inserted.
     * @param {Number|null} baseVersion Document {@link module:engine/model/document~Document#version} on which operation
     * can be applied or `null` if the operation operates on detached (non-document) tree.
     */
    constructor( position, nodes, baseVersion ) {
        super( baseVersion );

        /**
         * Position of insertion.
         *
         * @readonly
         * @member {module:engine/model/position~Position} module:engine/model/operation/insertoperation~InsertOperation#position
         */
        this.position = position.clone();
        this.position.stickiness = 'toNone';

        /**
         * List of nodes to insert.
         *
         * @readonly
         * @member {module:engine/model/nodelist~NodeList} module:engine/model/operation/insertoperation~InsertOperation#nodeList
         */
        this.nodes = new NodeList( _normalizeNodes( nodes ) );

        /**
         * Flag deciding how the operation should be transformed. If set to `true`, nodes might get additional attributes
         * during operational transformation. This happens when the operation insertion position is inside of a range
         * where attributes have changed.
         *
         * @member {Boolean} module:engine/model/operation/insertoperation~InsertOperation#shouldReceiveAttributes
         */
        this.shouldReceiveAttributes = false;
    }

    /**
     * @inheritDoc
     */
    get type() {
        return 'insert';
    }

    /**
     * Total offset size of inserted nodes.
     *
     * @returns {Number}
     */
    get howMany() {
        return this.nodes.maxOffset;
    }

    /**
     * Creates and returns an operation that has the same parameters as this operation.
     *
     * @returns {module:engine/model/operation/insertoperation~InsertOperation} Clone of this operation.
     */
    clone() {
        const nodes = new NodeList( [ ...this.nodes ].map( node => node._clone( true ) ) );
        const insert = new InsertOperation( this.position, nodes, this.baseVersion );

        insert.shouldReceiveAttributes = this.shouldReceiveAttributes;

        return insert;
    }

    /**
     * See {@link module:engine/model/operation/operation~Operation#getReversed `Operation#getReversed()`}.
     *
     * @returns {module:engine/model/operation/moveoperation~MoveOperation}
     */
    getReversed() {
        const graveyard = this.position.root.document.graveyard;
        const gyPosition = new Position( graveyard, [ 0 ] );

        return new MoveOperation( this.position, this.nodes.maxOffset, gyPosition, this.baseVersion + 1 );
    }

    /**
     * @inheritDoc
     */
    _validate() {
        const targetElement = this.position.parent;

        if ( !targetElement || targetElement.maxOffset < this.position.offset ) {
            /**
             * Insertion position is invalid.
             *
             * @error insert-operation-position-invalid
             */
            throw new CKEditorError(
                'insert-operation-position-invalid: Insertion position is invalid.',
                this
            );
        }
    }

    /**
     * @inheritDoc
     */
    _execute() {
        // What happens here is that we want original nodes be passed to writer because we want original nodes
        // to be inserted to the model. But in InsertOperation, we want to keep those nodes as they were added
        // to the operation, not modified. For example, text nodes can get merged or cropped while Elements can
        // get children. It is important that InsertOperation has the copy of original nodes in intact state.
        const originalNodes = this.nodes;
        this.nodes = new NodeList( [ ...originalNodes ].map( node => node._clone( true ) ) );

        _insert( this.position, originalNodes );
    }

    /**
     * @inheritDoc
     */
    toJSON() {
        const json = super.toJSON();

        json.position = this.position.toJSON();
        json.nodes = this.nodes.toJSON();

        return json;
    }

    /**
     * @inheritDoc
     */
    static get className() {
        return 'InsertOperation';
    }

    /**
     * Creates `InsertOperation` object from deserilized object, i.e. from parsed JSON string.
     *
     * @param {Object} json Deserialized JSON object.
     * @param {module:engine/model/document~Document} document Document on which this operation will be applied.
     * @returns {module:engine/model/operation/insertoperation~InsertOperation}
     */
    static fromJSON( json, document ) {
        const children = [];

        for ( const child of json.nodes ) {
            if ( child.name ) {
                // If child has name property, it is an Element.
                children.push( Element.fromJSON( child ) );
            } else {
                // Otherwise, it is a Text node.
                children.push( Text.fromJSON( child ) );
            }
        }

        const insert = new InsertOperation( Position.fromJSON( json.position, document ), children, json.baseVersion );
        insert.shouldReceiveAttributes = json.shouldReceiveAttributes;

        return insert;
    }

    // @if CK_DEBUG_ENGINE // toString() {
    // @if CK_DEBUG_ENGINE //     const nodeString = this.nodes.length > 1 ? `[ ${ this.nodes.length } ]` : this.nodes.getNode( 0 );

    // @if CK_DEBUG_ENGINE //    return `InsertOperation( ${ this.baseVersion } ): ${ nodeString } -> ${ this.position }`;
    // @if CK_DEBUG_ENGINE // }
}