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/text
 */

import Node from './node';

// @if CK_DEBUG_ENGINE // const { convertMapToStringifiedObject } = require( '../dev-utils/utils' );

/**
 * Model text node. Type of {@link module:engine/model/node~Node node} that contains {@link module:engine/model/text~Text#data text data}.
 *
 * **Important:** see {@link module:engine/model/node~Node} to read about restrictions using `Text` and `Node` API.
 *
 * **Note:** keep in mind that `Text` instances might indirectly got removed from model tree when model is changed.
 * This happens when {@link module:engine/model/writer~Writer model writer} is used to change model and the text node is merged with
 * another text node. Then, both text nodes are removed and a new text node is inserted into the model. Because of
 * this behavior, keeping references to `Text` is not recommended. Instead, consider creating
 * {@link module:engine/model/liveposition~LivePosition live position} placed before the text node.
 *
 * @extends module:engine/model/node~Node
 */
export default class Text extends Node {
    /**
     * Creates a text node.
     *
     * **Note:** Constructor of this class shouldn't be used directly in the code.
     * Use the {@link module:engine/model/writer~Writer#createText} method instead.
     *
     * @protected
     * @param {String} data Node's text.
     * @param {Object} [attrs] Node's attributes. See {@link module:utils/tomap~toMap} for a list of accepted values.
     */
    constructor( data, attrs ) {
        super( attrs );

        /**
         * Text data contained in this text node.
         *
         * @protected
         * @type {String}
         */
        this._data = data || '';
    }

    /**
     * @inheritDoc
     */
    get offsetSize() {
        return this.data.length;
    }

    /**
     * Returns a text data contained in the node.
     *
     * @readonly
     * @type {String}
     */
    get data() {
        return this._data;
    }

    /**
     * Checks whether this object is of the given.
     *
     *        text.is( 'text' ); // -> true
     *        text.is( 'node' ); // -> true
     *        text.is( 'model:text' ); // -> true
     *        text.is( 'model:node' ); // -> true
     *
     *        text.is( 'view:text' ); // -> false
     *        text.is( 'documentSelection' ); // -> false
     *
     * {@link module:engine/model/node~Node#is Check the entire list of model objects} which implement the `is()` method.
     *
     * @param {String} type Type to check when `name` parameter is present.
     * Otherwise, it acts like the `name` parameter.
     * @returns {Boolean}
     */
    is( type ) {
        return type === 'text' || type === 'model:text' ||
            // From super.is(). This is highly utilised method and cannot call super. See ckeditor/ckeditor5#6529.
            type === 'node' || type === 'model:node';
    }

    /**
     * Converts `Text` instance to plain object and returns it.
     *
     * @returns {Object} `Text` instance converted to plain object.
     */
    toJSON() {
        const json = super.toJSON();

        json.data = this.data;

        return json;
    }

    /**
     * Creates a copy of this text node and returns it. Created text node has same text data and attributes as original text node.
     *
     * @protected
     * @returns {module:engine/model/text~Text} `Text` instance created using given plain object.
     */
    _clone() {
        return new Text( this.data, this.getAttributes() );
    }

    /**
     * Creates a `Text` instance from given plain object (i.e. parsed JSON string).
     *
     * @param {Object} json Plain object to be converted to `Text`.
     * @returns {module:engine/model/text~Text} `Text` instance created using given plain object.
     */
    static fromJSON( json ) {
        return new Text( json.data, json.attributes );
    }

    // @if CK_DEBUG_ENGINE // toString() {
    // @if CK_DEBUG_ENGINE //     return `#${ this.data }`;
    // @if CK_DEBUG_ENGINE // }

    // @if CK_DEBUG_ENGINE // logExtended() {
    // @if CK_DEBUG_ENGINE //     console.log( `ModelText: ${ this }, attrs: ${ convertMapToStringifiedObject( this.getAttributes() ) }` );
    // @if CK_DEBUG_ENGINE // }

    // @if CK_DEBUG_ENGINE // log() {
    // @if CK_DEBUG_ENGINE //     console.log( 'ModelText: ' + this );
    // @if CK_DEBUG_ENGINE // }
}