Module

engine/conversion/downcasthelpers

@ckeditor/ckeditor5-engine/src/conversion/downcasthelpers

module

Contains downcast (model-to-view) converters for DowncastDispatcher.

Filtering

Classes

Type Definitions

  • HighlightDescriptor

    An object describing how the marker highlight should be represented in the view.

Functions

  • clearAttributes() → function

    static

    Function factory that creates a converter which clears artifacts after the previous model selection conversion. It removes all empty view attribute elements and merges sibling attributes at all start and end positions of all ranges.

       <p><strong>^</strong></p>
    -> <p>^</p>
    
       <p><strong>foo</strong>^<strong>bar</strong>bar</p>
    -> <p><strong>foo^bar<strong>bar</p>
    
       <p><strong>foo</strong><em>^</em><strong>bar</strong>bar</p>
    -> <p><strong>foo^bar<strong>bar</p>

    This listener should be assigned before any converter for the new selection:

    modelDispatcher.on( 'selection', clearAttributes() );

    See convertCollapsedSelection which does the opposite by breaking attributes in the selection position.

    Returns

    function

    Selection converter.

  • convertCollapsedSelection() → function

    static

    Function factory that creates a converter which converts a collapsed model selection to a view selection. The converter consumes appropriate value from the consumable object, maps the model selection position to the view position and breaks attribute elements at the selection position.

    modelDispatcher.on( 'selection', convertCollapsedSelection() );

    An example of the view state before and after converting the collapsed selection:

       <p><strong>f^oo<strong>bar</p>
    -> <p><strong>f</strong>^<strong>oo</strong>bar</p>

    By breaking attribute elements like <strong>, the selection is in a correct element. Then, when the selection attribute is converted, broken attributes might be merged again, or the position where the selection is may be wrapped with different, appropriate attribute elements.

    See also clearAttributes which does a clean-up by merging attributes.

    Returns

    function

    Selection converter.

  • convertRangeSelection() → function

    static

    Function factory that creates a converter which converts a non-collapsed model selection to a view selection. The converter consumes appropriate value from the consumable object and maps model positions from the selection to view positions.

    modelDispatcher.on( 'selection', convertRangeSelection() );

    Returns

    function

    Selection converter.

  • createViewElementFromHighlightDescriptor( writer, descriptor ) → AttributeElement

    static

    Creates a <span> view attribute element from the information provided by the highlight descriptor object. If a priority is not provided in the descriptor, the default priority will be used.

    Parameters

    writer : DowncastWriter
    descriptor : HighlightDescriptor

    Returns

    AttributeElement
  • insertElement( elementCreator ) → function

    protected static

    Function factory that creates a converter which converts node insertion changes from the model to the view. The function passed will be provided with all the parameters of the dispatcher's insert event. It is expected that the function returns an Element. The result of the function will be inserted into the view.

    The converter automatically consumes the corresponding value from the consumables list, stops the event (see DowncastDispatcher) and binds the model and view elements.

    downcastDispatcher.on(
        'insert:myElem',
        insertElement( ( modelItem, viewWriter ) => {
            const text = viewWriter.createText( 'myText' );
            const myElem = viewWriter.createElement( 'myElem', { myAttr: 'my-' + modelItem.getAttribute( 'myAttr' ) }, text );
    
            // Do something fancy with `myElem` using `modelItem` or other parameters.
    
            return myElem;
        }
    ) );

    Parameters

    elementCreator : function

    Function returning a view element, which will be inserted.

    Returns

    function

    Insert element event converter.

  • insertText() → function

    static

    Function factory that creates a default downcast converter for text insertion changes.

    The converter automatically consumes the corresponding value from the consumables list and stops the event (see DowncastDispatcher).

    modelDispatcher.on( 'insert:$text', insertText() );

    Returns

    function

    Insert text event converter.

  • insertUIElement( elementCreator ) → function

    protected static

    Function factory that creates a converter which converts marker adding change to the view UI element.

    The view UI element that will be added to the view depends on the passed parameter. See insertElement. In case of a non-collapsed range, the UI element will not wrap nodes but separate elements will be placed at the beginning and at the end of the range.

    This converter binds created UI elements with the marker name using bindElementToMarker.

    Parameters

    elementCreator : UIElement | function

    A view UI element or a function returning the view element that will be inserted.

    Returns

    function

    Insert element event converter.

  • remove() → function

    static

    Function factory that creates a default downcast converter for node remove changes.

    modelDispatcher.on( 'remove', remove() );

    Returns

    function

    Remove event converter.

  • wrap( elementCreator ) → function

    protected static

    Function factory that creates a converter which converts set/change/remove attribute changes from the model to the view. It can also be used to convert selection attributes. In that case, an empty attribute element will be created and the selection will be put inside it.

    Attributes from the model are converted to a view element that will be wrapping these view nodes that are bound to model elements having the given attribute. This is useful for attributes like bold that may be set on text nodes in the model but are represented as an element in the view:

    [paragraph]              MODEL ====> VIEW        <p>
        |- a {bold: true}                             |- <b>
        |- b {bold: true}                             |   |- ab
        |- c                                          |- c

    Passed Function will be provided with the attribute value and then all the parameters of the attribute event. It is expected that the function returns an Element. The result of the function will be the wrapping element. When the provided Function does not return any element, no conversion will take place.

    The converter automatically consumes the corresponding value from the consumables list and stops the event (see DowncastDispatcher).

    modelDispatcher.on( 'attribute:bold', wrap( ( modelAttributeValue, viewWriter ) => {
        return viewWriter.createAttributeElement( 'strong' );
    } );

    Parameters

    elementCreator : function

    Function returning a view element that will be used for wrapping.

    Returns

    function

    Set/change attribute converter.