src/model/textproxy.js
/**
* @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/textproxy
*/
import CKEditorError from '@ckeditor/ckeditor5-utils/src/ckeditorerror';
// @if CK_DEBUG_ENGINE // const { convertMapToStringifiedObject } = require( '../dev-utils/utils' );
/**
* `TextProxy` represents a part of {@link module:engine/model/text~Text text node}.
*
* Since {@link module:engine/model/position~Position positions} can be placed between characters of a text node,
* {@link module:engine/model/range~Range ranges} may contain only parts of text nodes. When {@link module:engine/model/range~Range#getItems
* getting items}
* contained in such range, we need to represent a part of that text node, since returning the whole text node would be incorrect.
* `TextProxy` solves this issue.
*
* `TextProxy` has an API similar to {@link module:engine/model/text~Text Text} and allows to do most of the common tasks performed
* on model nodes.
*
* **Note:** Some `TextProxy` instances may represent whole text node, not just a part of it.
* See {@link module:engine/model/textproxy~TextProxy#isPartial}.
*
* **Note:** `TextProxy` is not an instance of {@link module:engine/model/node~Node node}. Keep this in mind when using it as a
* parameter of methods.
*
* **Note:** `TextProxy` is a readonly interface. If you want to perform changes on model data represented by a `TextProxy`
* use {@link module:engine/model/writer~Writer model writer API}.
*
* **Note:** `TextProxy` instances are created on the fly, basing on the current state of model. Because of this, it is
* highly unrecommended to store references to `TextProxy` instances. `TextProxy` instances are not refreshed when
* model changes, so they might get invalidated. Instead, consider creating {@link module:engine/model/liveposition~LivePosition live
* position}.
*
* `TextProxy` instances are created by {@link module:engine/model/treewalker~TreeWalker model tree walker}. You should not need to create
* an instance of this class by your own.
*/
export default class TextProxy {
/**
* Creates a text proxy.
*
* @protected
* @param {module:engine/model/text~Text} textNode Text node which part is represented by this text proxy.
* @param {Number} offsetInText Offset in {@link module:engine/model/textproxy~TextProxy#textNode text node} from which the text proxy
* starts.
* @param {Number} length Text proxy length, that is how many text node's characters, starting from `offsetInText` it represents.
* @constructor
*/
constructor( textNode, offsetInText, length ) {
/**
* Text node which part is represented by this text proxy.
*
* @readonly
* @member {module:engine/model/text~Text}
*/
this.textNode = textNode;
if ( offsetInText < 0 || offsetInText > textNode.offsetSize ) {
/**
* Given `offsetInText` value is incorrect.
*
* @error model-textproxy-wrong-offsetintext
*/
throw new CKEditorError( 'model-textproxy-wrong-offsetintext: Given offsetInText value is incorrect.', this );
}
if ( length < 0 || offsetInText + length > textNode.offsetSize ) {
/**
* Given `length` value is incorrect.
*
* @error model-textproxy-wrong-length
*/
throw new CKEditorError( 'model-textproxy-wrong-length: Given length value is incorrect.', this );
}
/**
* Text data represented by this text proxy.
*
* @readonly
* @member {String}
*/
this.data = textNode.data.substring( offsetInText, offsetInText + length );
/**
* Offset in {@link module:engine/model/textproxy~TextProxy#textNode text node} from which the text proxy starts.
*
* @readonly
* @member {Number}
*/
this.offsetInText = offsetInText;
}
/**
* Offset at which this text proxy starts in it's parent.
*
* @see module:engine/model/node~Node#startOffset
* @readonly
* @type {Number}
*/
get startOffset() {
return this.textNode.startOffset !== null ? this.textNode.startOffset + this.offsetInText : null;
}
/**
* Offset size of this text proxy. Equal to the number of characters represented by the text proxy.
*
* @see module:engine/model/node~Node#offsetSize
* @readonly
* @type {Number}
*/
get offsetSize() {
return this.data.length;
}
/**
* Offset at which this text proxy ends in it's parent.
*
* @see module:engine/model/node~Node#endOffset
* @readonly
* @type {Number}
*/
get endOffset() {
return this.startOffset !== null ? this.startOffset + this.offsetSize : null;
}
/**
* Flag indicating whether `TextProxy` instance covers only part of the original {@link module:engine/model/text~Text text node}
* (`true`) or the whole text node (`false`).
*
* This is `false` when text proxy starts at the very beginning of {@link module:engine/model/textproxy~TextProxy#textNode textNode}
* ({@link module:engine/model/textproxy~TextProxy#offsetInText offsetInText} equals `0`) and text proxy sizes is equal to
* text node size.
*
* @readonly
* @type {Boolean}
*/
get isPartial() {
return this.offsetSize !== this.textNode.offsetSize;
}
/**
* Parent of this text proxy, which is same as parent of text node represented by this text proxy.
*
* @readonly
* @type {module:engine/model/element~Element|module:engine/model/documentfragment~DocumentFragment|null}
*/
get parent() {
return this.textNode.parent;
}
/**
* Root of this text proxy, which is same as root of text node represented by this text proxy.
*
* @readonly
* @type {module:engine/model/node~Node|module:engine/model/documentfragment~DocumentFragment}
*/
get root() {
return this.textNode.root;
}
/**
* Checks whether this object is of the given.
*
* textProxy.is( 'textProxy' ); // -> true
* textProxy.is( 'model:textProxy' ); // -> true
*
* textProxy.is( 'view:textProxy' ); // -> false
* textProxy.is( 'range' ); // -> false
*
* {@link module:engine/model/node~Node#is Check the entire list of model objects} which implement the `is()` method.
*
* @param {String} type
* @returns {Boolean}
*/
is( type ) {
return type === 'textProxy' || type === 'model:textProxy';
}
/**
* Gets path to this text proxy.
*
* @see module:engine/model/node~Node#getPath
* @returns {Array.<Number>}
*/
getPath() {
const path = this.textNode.getPath();
if ( path.length > 0 ) {
path[ path.length - 1 ] += this.offsetInText;
}
return path;
}
/**
* Returns ancestors array of this text proxy.
*
* @param {Object} options Options object.
* @param {Boolean} [options.includeSelf=false] When set to `true` this text proxy will be also included in parent's array.
* @param {Boolean} [options.parentFirst=false] When set to `true`, array will be sorted from text proxy parent to root element,
* otherwise root element will be the first item in the array.
* @returns {Array} Array with ancestors.
*/
getAncestors( options = { includeSelf: false, parentFirst: false } ) {
const ancestors = [];
let parent = options.includeSelf ? this : this.parent;
while ( parent ) {
ancestors[ options.parentFirst ? 'push' : 'unshift' ]( parent );
parent = parent.parent;
}
return ancestors;
}
/**
* Checks if this text proxy has an attribute for given key.
*
* @param {String} key Key of attribute to check.
* @returns {Boolean} `true` if attribute with given key is set on text proxy, `false` otherwise.
*/
hasAttribute( key ) {
return this.textNode.hasAttribute( key );
}
/**
* Gets an attribute value for given key or `undefined` if that attribute is not set on text proxy.
*
* @param {String} key Key of attribute to look for.
* @returns {*} Attribute value or `undefined`.
*/
getAttribute( key ) {
return this.textNode.getAttribute( key );
}
/**
* Returns iterator that iterates over this node's attributes. Attributes are returned as arrays containing two
* items. First one is attribute key and second is attribute value.
*
* This format is accepted by native `Map` object and also can be passed in `Node` constructor.
*
* @returns {Iterable.<*>}
*/
getAttributes() {
return this.textNode.getAttributes();
}
/**
* Returns iterator that iterates over this node's attribute keys.
*
* @returns {Iterable.<String>}
*/
getAttributeKeys() {
return this.textNode.getAttributeKeys();
}
// @if CK_DEBUG_ENGINE // toString() {
// @if CK_DEBUG_ENGINE // return `#${ this.data }`;
// @if CK_DEBUG_ENGINE // }
// @if CK_DEBUG_ENGINE // log() {
// @if CK_DEBUG_ENGINE // console.log( 'ModelTextProxy: ' + this );
// @if CK_DEBUG_ENGINE // }
// @if CK_DEBUG_ENGINE // logExtended() {
// @if CK_DEBUG_ENGINE // console.log( `ModelTextProxy: ${ this }, ` +
// @if CK_DEBUG_ENGINE // `attrs: ${ convertMapToStringifiedObject( this.getAttributes() ) }` );
// @if CK_DEBUG_ENGINE // }
}