/** * @license Copyright (c) 2003-2018, CKSource - Frederico Knabben. All rights reserved. * For licensing, see LICENSE.md. */ /** * @module engine/conversion/conversion */ import CKEditorError from '@ckeditor/ckeditor5-utils/src/ckeditorerror'; /** * A utility class that helps add converters to upcast and downcast dispatchers. * * We recommend reading the {@glink framework/guides/architecture/editing-engine Editing engine architecture} guide first to * understand the core concepts of the conversion mechanisms. * * The instance of the conversion manager is available in the * {@link module:core/editor/editor~Editor#conversion `editor.conversion`} property * and by default has the following groups of dispatchers (i.e. directions of conversion): * * * `downcast` (editing and data downcasts) * * `editingDowncast` * * `dataDowncast` * * `upcast` * * To add a converter to a specific group, use the {@link module:engine/conversion/conversion~Conversion#for `for()`} * method: * * // Add a converter to editing downcast and data downcast. * editor.conversion.for( 'downcast' ).elementToElement( config ) ); * * // Add a converter to the data pipepline only: * editor.conversion.for( 'dataDowncast' ).elementToElement( dataConversionConfig ) ); * * // And a slightly different one for the editing pipeline: * editor.conversion.for( 'editingDowncast' ).elementToElement( editingConversionConfig ) ); * * The functions used in `add()` calls are one-way converters (i.e. you need to remember yourself to add * a converter in the other direction, if your feature requires that). They are also called "conversion helpers". * You can find a set of them in the {@link module:engine/conversion/downcasthelpers} and * {@link module:engine/conversion/upcasthelpers} modules. * * Besides allowing to register converters to specific dispatchers, you can also use methods available in this * class to add two-way converters (upcast and downcast): * * * {@link module:engine/conversion/conversion~Conversion#elementToElement `elementToElement()`} – * Model element to view element and vice versa. * * {@link module:engine/conversion/conversion~Conversion#attributeToElement `attributeToElement()`} – * Model attribute to view element and vice versa. * * {@link module:engine/conversion/conversion~Conversion#attributeToAttribute `attributeToAttribute()`} – * Model attribute to view element and vice versa. */ export default class Conversion { /** * Creates a new conversion instance. */ constructor() { /** * @private * @member {Map} */ this._conversionHelpers = new Map(); } /** * Registers one or more converters under a given group name. The group name can then be used to assign a converter * to multiple dispatchers at once. * * If a given group name is used for the second time, the * {@link module:utils/ckeditorerror~CKEditorError `conversion-register-group-exists` error} is thrown. * * @param {String} name The name for dispatchers group. * @param {module:engine/conversion/downcasthelpers~DowncastHelpers| * module:engine/conversion/upcasthelpers~UpcastHelpers} conversionHelpers */ register( name, conversionHelpers ) { if ( this._conversionHelpers.has( name ) ) { /** * Trying to register a group name that was already registered. * * @error conversion-register-group-exists */ throw new CKEditorError( 'conversion-register-group-exists: Trying to register a group name that was already registered.' ); } this._conversionHelpers.set( name, conversionHelpers ); } /** * Provides chainable API to assign converters to dispatchers registered under a given group name. Converters are added * by calling the {@link module:engine/conversion/conversion~ConversionHelpers#add `.add()`} method of an * {@link module:engine/conversion/conversion~ConversionHelpers conversion helpers} returned by this function. * * editor.conversion.for( 'downcast' ) * .add( conversionHelperA ) // Adds a custom converter A. * .add( conversionHelperB ) // Adds a custom converter B. * .elementToElement( config ); // Adds a custom element-to-element downcast converter. * * In this example `conversionHelperA` and `conversionHelperB` will be called for all dispatchers from the `'model'` group. * * The `.add()` method takes exactly one parameter, which is a function. This function should accept one parameter that * is a dispatcher instance. The function should add an actual converter to the passed dispatcher instance. * * Conversion helpers for most common cases are already provided. They are flexible enough to cover most use cases. * See the documentation to learn how they can be configured. * * For downcast (model-to-view conversion), these are: * * * {@link module:engine/conversion/downcasthelpers~DowncastHelpers#elementToElement Downcast element-to-element converter}, * * {@link module:engine/conversion/downcasthelpers~DowncastHelpers#attributeToElement Downcast attribute-to-element converter}, * * {@link module:engine/conversion/downcasthelpers~DowncastHelpers#attributeToAttribute Downcast attribute-to-attribute converter}. * * {@link module:engine/conversion/downcasthelpers~DowncastHelpers#markerToElement Downcast marker-to-element converter}. * * {@link module:engine/conversion/downcasthelpers~DowncastHelpers#markerToHighlight Downcast marker-to-highlight converter}. * * For upcast (view-to-model conversion), these are: * * * {@link module:engine/conversion/upcasthelpers~UpcastHelpers#elementToElement Upcast element-to-element converter}, * * {@link module:engine/conversion/upcasthelpers~UpcastHelpers#elementToAttribute Upcast attribute-to-element converter}, * * {@link module:engine/conversion/upcasthelpers~UpcastHelpers#attributeToAttribute Upcast attribute-to-attribute converter}. * * {@link module:engine/conversion/upcasthelpers~UpcastHelpers#elementToMarker Upcast element-to-marker converter}. * * An example of using conversion helpers to convert the `paragraph` model element to the `p` view element (and back): * * // Define conversion configuration - model element 'paragraph' should be converted to view element 'p'. * const config = { model: 'paragraph', view: 'p' }; * * // Add converters to proper dispatchers using conversion helpers. * editor.conversion.for( 'downcast' ).elementToElement( config ) ); * editor.conversion.for( 'upcast' ).elementToElement( config ) ); * * @param {String} groupName The name of dispatchers group to add the converters to. * @returns {module:engine/conversion/downcasthelpers~DowncastHelpers|module:engine/conversion/upcasthelpers~UpcastHelpers} */ for( groupName ) { return this._getConversionHelpers( groupName ); } /** * Sets up converters between the model and the view that convert a model element to a view element (and vice versa). * For example, the model `Foo` is `

Foo

` in the view. * * // A simple conversion from the `paragraph` model element to the `

` view element (and vice versa). * conversion.elementToElement( { model: 'paragraph', view: 'p' } ); * * // Override other converters by specifying a converter definition with a higher priority. * conversion.elementToElement( { model: 'paragraph', view: 'div', converterPriority: 'high' } ); * * // View specified as an object instead of a string. * conversion.elementToElement( { * model: 'fancyParagraph', * view: { * name: 'p', * classes: 'fancy' * } * } ); * * // Use `upcastAlso` to define other view elements that should also be converted to a `paragraph` element. * conversion.elementToElement( { * model: 'paragraph', * view: 'p', * upcastAlso: [ * 'div', * { * // Any element with the `display: block` style. * styles: { * display: 'block' * } * } * ] * } ); * * // `upcastAlso` set as callback enables a conversion of a wide range of different view elements. * conversion.elementToElement( { * model: 'heading', * view: 'h2', * // Convert "headling-like" paragraphs to headings. * upcastAlso: viewElement => { * const fontSize = viewElement.getStyle( 'font-size' ); * * if ( !fontSize ) { * return null; * } * * const match = fontSize.match( /(\d+)\s*px/ ); * * if ( !match ) { * return null; * } * * const size = Number( match[ 1 ] ); * * if ( size > 26 ) { * // Returned value can be an object with the matched properties. * // These properties will be "consumed" during the conversion. * // See `engine.view.Matcher~MatcherPattern` and `engine.view.Matcher#match` for more details. * * return { name: true, styles: [ 'font-size' ] }; * } * * return null; * } * } ); * * `definition.model` is a `String` with a model element name to convert from or to. * See {@link module:engine/conversion/conversion~ConverterDefinition} to learn about other parameters. * * @param {module:engine/conversion/conversion~ConverterDefinition} definition The converter definition. */ elementToElement( definition ) { // Set up downcast converter. this.for( 'downcast' ).elementToElement( definition ); // Set up upcast converter. for ( const { model, view } of _getAllUpcastDefinitions( definition ) ) { this.for( 'upcast' ) .elementToElement( { model, view, converterPriority: definition.converterPriority } ); } } /** * Sets up converters between the model and the view that convert a model attribute to a view element (and vice versa). * For example, a model text node with `"Foo"` as data and the `bold` attribute is `Foo` in the view. * * // A simple conversion from the `bold=true` attribute to the `` view element (and vice versa). * conversion.attributeToElement( { model: 'bold', view: 'strong' } ); * * // Override other converters by specifying a converter definition with a higher priority. * conversion.attributeToElement( { model: 'bold', view: 'b', converterPriority: 'high' } ); * * // View specified as an object instead of a string. * conversion.attributeToElement( { * model: 'bold', * view: { * name: 'span', * classes: 'bold' * } * } ); * * // Use `config.model.name` to define the conversion only from a given node type, `$text` in this case. * // The same attribute on different elements may then be handled by a different converter. * conversion.attributeToElement( { * model: { * key: 'textDecoration', * values: [ 'underline', 'lineThrough' ], * name: '$text' * }, * view: { * underline: { * name: 'span', * styles: { * 'text-decoration': 'underline' * } * }, * lineThrough: { * name: 'span', * styles: { * 'text-decoration': 'line-through' * } * } * } * } ); * * // Use `upcastAlso` to define other view elements that should also be converted to the `bold` attribute. * conversion.attributeToElement( { * model: 'bold', * view: 'strong', * upcastAlso: [ * 'b', * { * name: 'span', * classes: 'bold' * }, * { * name: 'span', * styles: { * 'font-weight': 'bold' * } * }, * viewElement => { * const fontWeight = viewElement.getStyle( 'font-weight' ); * * if ( viewElement.is( 'span' ) && fontWeight && /\d+/.test() && Number( fontWeight ) > 500 ) { * // Returned value can be an object with the matched properties. * // These properties will be "consumed" during the conversion. * // See `engine.view.Matcher~MatcherPattern` and `engine.view.Matcher#match` for more details. * * return { * name: true, * styles: [ 'font-weight' ] * }; * } * } * ] * } ); * * // Conversion from and to a model attribute key whose value is an enum (`fontSize=big|small`). * // `upcastAlso` set as callback enables a conversion of a wide range of different view elements. * conversion.attributeToElement( { * model: { * key: 'fontSize', * values: [ 'big', 'small' ] * }, * view: { * big: { * name: 'span', * styles: { * 'font-size': '1.2em' * } * }, * small: { * name: 'span', * styles: { * 'font-size': '0.8em' * } * } * }, * upcastAlso: { * big: viewElement => { * const fontSize = viewElement.getStyle( 'font-size' ); * * if ( !fontSize ) { * return null; * } * * const match = fontSize.match( /(\d+)\s*px/ ); * * if ( !match ) { * return null; * } * * const size = Number( match[ 1 ] ); * * if ( viewElement.is( 'span' ) && size > 10 ) { * // Returned value can be an object with the matched properties. * // These properties will be "consumed" during the conversion. * // See `engine.view.Matcher~MatcherPattern` and `engine.view.Matcher#match` for more details. * * return { name: true, styles: [ 'font-size' ] }; * } * * return null; * }, * small: viewElement => { * const fontSize = viewElement.getStyle( 'font-size' ); * * if ( !fontSize ) { * return null; * } * * const match = fontSize.match( /(\d+)\s*px/ ); * * if ( !match ) { * return null; * } * * const size = Number( match[ 1 ] ); * * if ( viewElement.is( 'span' ) && size < 10 ) { * // Returned value can be an object with the matched properties. * // These properties will be "consumed" during the conversion. * // See `engine.view.Matcher~MatcherPattern` and `engine.view.Matcher#match` for more details. * * return { name: true, styles: [ 'font-size' ] }; * } * * return null; * } * } * } ); * * The `definition.model` parameter specifies which model attribute should be converted from or to. It can be a `{ key, value }` object * describing the attribute key and value to convert or a `String` specifying just the attribute key (then `value` is set to `true`). * See {@link module:engine/conversion/conversion~ConverterDefinition} to learn about other parameters. * * @param {module:engine/conversion/conversion~ConverterDefinition} definition The converter definition. */ attributeToElement( definition ) { // Set up downcast converter. this.for( 'downcast' ).attributeToElement( definition ); // Set up upcast converter. for ( const { model, view } of _getAllUpcastDefinitions( definition ) ) { this.for( 'upcast' ) .elementToAttribute( { view, model, converterPriority: definition.priority } ); } } /** * Sets up converters between the model and the view that convert a model attribute to a view attribute (and vice versa). * For example, `` is converted to `` (the same attribute key and value). * This type of converters is intended to be used with {@link module:engine/model/element~Element model element} nodes. * To convert text attributes {@link module:engine/conversion/conversion~Conversion#attributeToElement `attributeToElement converter`} * should be set up. * * // A simple conversion from the `source` model attribute to the `src` view attribute (and vice versa). * conversion.attributeToAttribute( { model: 'source', view: 'src' } ); * * // Attribute values are strictly specified. * conversion.attributeToAttribute( { * model: { * name: 'image', * key: 'aside', * values: [ 'aside' ] * }, * view: { * aside: { * name: 'img', * key: 'class', * value: [ 'aside', 'half-size' ] * } * } * } ); * * // Set the style attribute. * conversion.attributeToAttribute( { * model: { * name: 'image', * key: 'aside', * values: [ 'aside' ] * }, * view: { * aside: { * name: 'img', * key: 'style', * value: { * float: 'right', * width: '50%', * margin: '5px' * } * } * } * } ); * * // Conversion from and to a model attribute key whose value is an enum (`align=right|center`). * // Use `upcastAlso` to define other view elements that should also be converted to the `align=right` attribute. * conversion.attributeToAttribute( { * model: { * key: 'align', * values: [ 'right', 'center' ] * }, * view: { * right: { * key: 'class', * value: 'align-right' * }, * center: { * key: 'class', * value: 'align-center' * } * }, * upcastAlso: { * right: { * styles: { * 'text-align': 'right' * } * }, * center: { * styles: { * 'text-align': 'center' * } * } * } * } ); * * The `definition.model` parameter specifies which model attribute should be converted from and to. * It can be a `{ key, [ values ], [ name ] }` object or a `String`, which will be treated like `{ key: definition.model }`. * The `key` property is the model attribute key to convert from and to. * The `values` are the possible model attribute values. If `values` is not set, the model attribute value will be the same as the * view attribute value. * If `name` is set, the conversion will be set up only for model elements with the given name. * * The `definition.view` parameter specifies which view attribute should be converted from and to. * It can be a `{ key, value, [ name ] }` object or a `String`, which will be treated like `{ key: definition.view }`. * The `key` property is the view attribute key to convert from and to. * The `value` is the view attribute value to convert from and to. If `definition.value` is not set, the view attribute value will be * the same as the model attribute value. * If `key` is `'class'`, `value` can be a `String` or an array of `String`s. * If `key` is `'style'`, `value` is an object with key-value pairs. * In other cases, `value` is a `String`. * If `name` is set, the conversion will be set up only for model elements with the given name. * If `definition.model.values` is set, `definition.view` is an object that assigns values from `definition.model.values` * to `{ key, value, [ name ] }` objects. * * `definition.upcastAlso` specifies which other matching view elements should also be upcast to the given model configuration. * If `definition.model.values` is set, `definition.upcastAlso` should be an object assigning values from `definition.model.values` * to {@link module:engine/view/matcher~MatcherPattern}s or arrays of {@link module:engine/view/matcher~MatcherPattern}s. * * **Note:** `definition.model` and `definition.view` form should be mirrored, so the same types of parameters should * be given in both parameters. * * @param {Object} definition The converter definition. * @param {String|Object} definition.model The model attribute to convert from and to. * @param {String|Object} definition.view The view attribute to convert from and to. * @param {module:engine/view/matcher~MatcherPattern|Array.} [definition.upcastAlso] * Any view element matching `definition.upcastAlso` will also be converted to the given model attribute. `definition.upcastAlso` * is used only if `config.model.values` is specified. */ attributeToAttribute( definition ) { // Set up downcast converter. this.for( 'downcast' ).attributeToAttribute( definition ); // Set up upcast converter. for ( const { model, view } of _getAllUpcastDefinitions( definition ) ) { this.for( 'upcast' ) .attributeToAttribute( { view, model } ); } } /** * Returns conversion helpers registered under a given name. * * If the given group name has not been registered, the * {@link module:utils/ckeditorerror~CKEditorError `conversion-for-unknown-group` error} is thrown. * * @private * @param {String} groupName * @returns {module:engine/conversion/downcasthelpers~DowncastHelpers|module:engine/conversion/upcasthelpers~UpcastHelpers} */ _getConversionHelpers( groupName ) { if ( !this._conversionHelpers.has( groupName ) ) { /** * Trying to add a converter to an unknown dispatchers group. * * @error conversion-for-unknown-group */ throw new CKEditorError( 'conversion-for-unknown-group: Trying to add a converter to an unknown dispatchers group.' ); } return this._conversionHelpers.get( groupName ); } } /** * Defines how the model should be converted from and to the view. * * @typedef {Object} module:engine/conversion/conversion~ConverterDefinition * * @property {*} [model] The model conversion definition. Describes the model element or model attribute to convert. This parameter differs * for different functions that accept `ConverterDefinition`. See the description of the function to learn how to set it. * @property {module:engine/view/elementdefinition~ElementDefinition|Object} view The definition of the view element to convert from and * to. If `model` describes multiple values, `view` is an object that assigns these values (`view` object keys) to view element definitions * (`view` object values). * @property {module:engine/view/matcher~MatcherPattern|Array.} [upcastAlso] * Any view element matching `upcastAlso` will also be converted to the model. If `model` describes multiple values, `upcastAlso` * is an object that assigns these values (`upcastAlso` object keys) to {@link module:engine/view/matcher~MatcherPattern}s * (`upcastAlso` object values). * @property {module:utils/priorities~PriorityString} [converterPriority] The converter priority. */ // Helper function that creates a joint array out of an item passed in `definition.view` and items passed in // `definition.upcastAlso`. // // @param {module:engine/conversion/conversion~ConverterDefinition} definition // @returns {Array} Array containing view definitions. function* _getAllUpcastDefinitions( definition ) { if ( definition.model.values ) { for ( const value of definition.model.values ) { const model = { key: definition.model.key, value }; const view = definition.view[ value ]; const upcastAlso = definition.upcastAlso ? definition.upcastAlso[ value ] : undefined; yield* _getUpcastDefinition( model, view, upcastAlso ); } } else { yield* _getUpcastDefinition( definition.model, definition.view, definition.upcastAlso ); } } function* _getUpcastDefinition( model, view, upcastAlso ) { yield { model, view }; if ( upcastAlso ) { upcastAlso = Array.isArray( upcastAlso ) ? upcastAlso : [ upcastAlso ]; for ( const upcastAlsoItem of upcastAlso ) { yield { model, view: upcastAlsoItem }; } } } /** * Base class for conversion helpers. */ export class ConversionHelpers { /** * Creates ConversionHelpers instance. * * @param {Array.} dispatcher */ constructor( dispatcher ) { this._dispatchers = Array.isArray( dispatcher ) ? dispatcher : [ dispatcher ]; } /** * Registers a conversion helper. * * **Note**: See full usage example in the `{@link module:engine/conversion/conversion~Conversion#for conversion.for()}` * method description * * @param {Function} conversionHelper The function to be called on event. * @returns {module:engine/conversion/downcasthelpers~DowncastHelpers|module:engine/conversion/upcasthelpers~UpcastHelpers} */ add( conversionHelper ) { this._addToDispatchers( conversionHelper ); return this; } /** * Helper function for the `Conversion` `.add()` method. * * Calls `conversionHelper` on each dispatcher from the group specified earlier in the `.for()` call, effectively * adding converters to all specified dispatchers. * * @private * @param {Function} conversionHelper */ _addToDispatchers( conversionHelper ) { for ( const dispatcher of this._dispatchers ) { conversionHelper( dispatcher ); } } }