Conversion
A utility class that helps add converters to upcast and downcast dispatchers.
We recommend reading the editor conversion guide first to understand the core concepts of the conversion mechanisms.
An instance of the conversion manager is available in the editor.conversion property and by default has the following groups of dispatchers (i.e. directions of conversion):
downcast(editing and data downcasts)editingDowncastdataDowncastupcast
One-way converters
To add a converter to a specific group, use the 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 ) );
See for() method documentation to learn more about available conversion helpers and how to use your custom ones.
Two-way converters
Besides using one-way converters via the for() method, you can also use other methods available in this class to add two-way converters (upcast and downcast):
elementToElement()– Model element to view element and vice versa.attributeToElement()– Model attribute to view element and vice versa.attributeToAttribute()– Model attribute to view attribute and vice versa.
Properties
_downcast : Array<DowncastDispatcher>privatereadonlymodule:engine/conversion/conversion~Conversion#_downcast_helpers : Map<string, DowncastHelpers | UpcastHelpers>privatereadonlymodule:engine/conversion/conversion~Conversion#_helpersMaps dispatchers group name to ConversionHelpers instances.
_upcast : Array<UpcastDispatcher>privatereadonlymodule:engine/conversion/conversion~Conversion#_upcast
Methods
constructor( downcastDispatchers, upcastDispatchers )module:engine/conversion/conversion~Conversion#constructorCreates a new conversion instance.
Parameters
downcastDispatchers : ArrayOrItem<DowncastDispatcher>upcastDispatchers : ArrayOrItem<UpcastDispatcher>
addAlias( alias, dispatcher ) → voidmodule:engine/conversion/conversion~Conversion#addAliasaddAlias( alias, dispatcher ) → voidmodule:engine/conversion/conversion~Conversion#addAliasaddAlias( alias, dispatcher ) → voidmodule:engine/conversion/conversion~Conversion#addAliasattributeToAttribute( definition = { [definition.converterPriority], definition.model, [definition.upcastAlso], definition.view, [definition.converterPriority], definition.model, [definition.upcastAlso], definition.view } ) → voidmodule:engine/conversion/conversion~Conversion#attributeToAttributeSets up converters between the model and the view that convert a model attribute to a view attribute (and vice versa). For example,
<imageBlock src='foo.jpg'></imageBlock>is converted to<img src='foo.jpg'></img>(the same attribute key and value). This type of converters is intended to be used with model element nodes. To convert the text attributes, theattributeToElement convertershould be set up.// A simple conversion from the `source` model attribute to the `src` view attribute (and vice versa). editor.conversion.attributeToAttribute( { model: 'source', view: 'src' } ); // Attribute values are strictly specified. editor.conversion.attributeToAttribute( { model: { name: 'imageInline', key: 'aside', values: [ 'aside' ] }, view: { aside: { name: 'img', key: 'class', value: [ 'aside', 'half-size' ] } } } ); // Set the style attribute. editor.conversion.attributeToAttribute( { model: { name: 'imageInline', 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. editor.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' } } } } );Copy codeThe
definition.modelparameter specifies which model attribute should be converted from and to. It can be a{ key, [ values ], [ name ] }object or aString, which will be treated like{ key: definition.model }. Thekeyproperty is the model attribute key to convert from and to. Thevaluesare the possible model attribute values. If thevaluesparameter is not set, the model attribute value will be the same as the view attribute value. Ifnameis set, the conversion will be set up only for model elements with the given name.The
definition.viewparameter specifies which view attribute should be converted from and to. It can be a{ key, value, [ name ] }object or aString, which will be treated like{ key: definition.view }. Thekeyproperty is the view attribute key to convert from and to. Thevalueis the view attribute value to convert from and to. Ifdefinition.valueis not set, the view attribute value will be the same as the model attribute value. Ifkeyis'class',valuecan be aStringor an array ofStrings. Ifkeyis'style',valueis an object with key-value pairs. In other cases,valueis aString. Ifnameis set, the conversion will be set up only for model elements with the given name. Ifdefinition.model.valuesis set,definition.viewis an object that assigns values fromdefinition.model.valuesto{ key, value, [ name ] }objects.definition.upcastAlsospecifies which other matching view elements should also be upcast to the given model configuration. Ifdefinition.model.valuesis set,definition.upcastAlsoshould be an object assigning values fromdefinition.model.valuestoMatcherPatterns or arrays ofMatcherPatterns.Note:
definition.modelanddefinition.viewform should be mirrored, so the same types of parameters should be given in both parameters.Type parameters
TValues : extends string
Parameters
definition : objectThe converter definition.
Properties[ definition.converterPriority ] : PriorityStringdefinition.model : string | objectThe model attribute to convert from and to.
[ definition.upcastAlso ] : ArrayOrItem<( string | DowncastAttributeCreatorFunction | (DowncastAttributeDescriptor & { name?: string | undefined; }) )>Any view element matching
definition.upcastAlsowill also be converted to the given model attribute.definition.upcastAlsois used only ifconfig.model.valuesis specified.definition.view : string | ( DowncastAttributeDescriptor & { name?: string | undefined; } )The view attribute to convert from and to.
[ definition.converterPriority ] : PriorityStringdefinition.model : objectThe model attribute to convert from and to.
[ definition.upcastAlso ] : Record<TValues, DowncastAttributeCreatorFunction | ( DowncastAttributeDescriptor & { name?: string | undefined; } )>Any view element matching
definition.upcastAlsowill also be converted to the given model attribute.definition.upcastAlsois used only ifconfig.model.valuesis specified.definition.view : Record<TValues, object>The view attribute to convert from and to.
Returns
void
attributeToElement( definition = { [definition.converterPriority], definition.model, [definition.upcastAlso], definition.view, [definition.converterPriority], definition.model, [definition.upcastAlso], definition.view } ) → voidmodule:engine/conversion/conversion~Conversion#attributeToElementSets 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 theboldattribute will be turned to<strong>Foo</strong>in the view.// A simple conversion from the `bold=true` attribute to the `<strong>` view element (and vice versa). editor.conversion.attributeToElement( { model: 'bold', view: 'strong' } ); // Override other converters by specifying a converter definition with a higher priority. editor.conversion.attributeToElement( { model: 'bold', view: 'b', converterPriority: 'high' } ); // View specified as an object instead of a string. editor.conversion.attributeToElement( { model: 'bold', view: { name: 'span', classes: 'bold' } } ); // Use `config.model.name` to define the conversion only from a given node type, `$text` in this case. // The same attribute on different elements may then be handled by a different converter. editor.conversion.attributeToElement( { model: { key: 'textDecoration', values: [ 'underline', 'lineThrough' ], name: '$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. editor.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( 'element', '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. editor.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( 'element', '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( 'element', '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; } } } );Copy codeThe
definition.modelparameter 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 aStringspecifying just the attribute key (in such a casevalueis set totrue).Type parameters
TValues : extends string
Parameters
definition : objectThe converter definition.
Properties[ definition.converterPriority ] : PriorityStringdefinition.model : string | object[ definition.upcastAlso ] : ArrayOrItem<MatcherPattern>definition.view : ViewElementDefinition[ definition.converterPriority ] : PriorityStringdefinition.model : object[ definition.upcastAlso ] : Record<TValues, ArrayOrItem<MatcherPattern>>definition.view : Record<TValues, ViewElementDefinition>
Returns
void
elementToElement( definition = { [definition.converterPriority], definition.model, [definition.upcastAlso], definition.view } ) → voidmodule:engine/conversion/conversion~Conversion#elementToElementSets up converters between the model and the view that convert a model element to a view element (and vice versa). For example, the model
<paragraph>Foo</paragraph>is turned into<p>Foo</p>in the view.// A simple conversion from the `paragraph` model element to the `<p>` view element (and vice versa). editor.conversion.elementToElement( { model: 'paragraph', view: 'p' } ); // Override other converters by specifying a converter definition with a higher priority. editor.conversion.elementToElement( { model: 'paragraph', view: 'div', converterPriority: 'high' } ); // View specified as an object instead of a string. editor.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. editor.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. editor.conversion.elementToElement( { model: 'heading', view: 'h2', // Convert "heading-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; } } );Copy codedefinition.modelis aStringwith a model element name to convert from or to.Parameters
definition : objectThe converter definition.
Properties[ definition.converterPriority ] : PriorityStringdefinition.model : string[ definition.upcastAlso ] : ArrayOrItem<string | RegExp | MatcherFunctionPattern | MatcherObjectPattern | ViewElementObjectDefinition>definition.view : ViewElementDefinition
Returns
void
for( groupName ) → UpcastHelpersmodule:engine/conversion/conversion~Conversion#forfor( groupName ) → ConversionType<T>module:engine/conversion/conversion~Conversion#forType parameters
T : extends string
Parameters
groupName : T
Returns
for( groupName ) → DowncastHelpersmodule:engine/conversion/conversion~Conversion#forParameters
groupName : 'downcast' | 'dataDowncast' | 'editingDowncast'
Returns
_createConversionHelpers( options = { options.dispatchers, options.isDowncast, options.name } ) → voidprivatemodule:engine/conversion/conversion~Conversion#_createConversionHelpersCreates and caches conversion helpers for given dispatchers group.
Parameters
options : objectGroup name.
Propertiesoptions.dispatchers : Array<DowncastDispatcher | UpcastDispatcher>Dispatchers to register.
options.isDowncast : booleanWhether downcast group.
options.name : stringGroup name.
Returns
void