Class

UIElement (engine/view)

@ckeditor/ckeditor5-engine/src/view/uielement

class

UI element class. It should be used to represent editing UI which needs to be injected into the editing view If possible, you should keep your UI outside the editing view. However, if that is not possible, UI elements can be used.

How a UI element is rendered is in your control (you pass a callback to downcastWriter#createUIElement()). The editor will ignore your UI element – the selection cannot be placed in it, it is skipped (invisible) when the user modifies the selection by using arrow keys and the editor does not listen to any mutations which happen inside your UI elements.

The limitation is that you cannot convert a model element to a UI element. UI elements need to be created for markers or as additinal elements inside normal container elements.

To create a new UI element use the downcastWriter#createUIElement() method.

Filtering

Properties

  • childCount : Number

    readonly inherited

    Number of element's children.

  • document : Document | null

    readonly inherited

    View document that owns this node, or null if the node is inside document fragment.

  • index : Number | null

    readonly inherited

    Index of the node in the parent element or null if the node has no parent.

    Accessing this property throws an error if this node's parent element does not contain it. This means that view tree got broken.

  • isEmpty : Boolean

    readonly inherited

    Is true if there are no nodes inside this element, false otherwise.

  • name : String

    readonly inherited

    Name of the element.

  • nextSibling : Node | null

    readonly inherited

    Node's next sibling, or null if it is the last child.

  • parent : Element | DocumentFragment | null

    readonly inherited

    Parent element. Null by default. Set by _insertChild.

  • previousSibling : Node | null

    readonly inherited

    Node's previous sibling, or null if it is the first child.

  • root : Node | DocumentFragment

    readonly inherited

    Top-most ancestor of the node. If the node has no parent it is the root itself.

  • _attrs : Map

    protected inherited

    Map of attributes, where attributes names are keys and attributes values are values.

  • _children : Array.<Node>

    protected inherited

    Array of child nodes.

  • _classes : Set

    protected inherited

    Set of classes associated with element instance.

  • _customProperties : Map

    protected inherited

    Map of custom properties. Custom properties can be added to element instance, will be cloned but not rendered into DOM.

  • _styles : Map

    protected inherited

    Map of styles.

Methods

  • constructor( name, [ attributes ] )

    protected

    Creates new instance of UIElement.

    Throws CKEditorError view-uielement-cannot-add when third parameter is passed, to inform that usage of UIElement is incorrect (adding child nodes to UIElement is forbidden).

    Parameters

    name : String

    Node name.

    [ attributes ] : Object | Iterable

    Collection of attributes.

    Related:

  • findAncestor( patterns ) → Element | null

    inherited

    Returns ancestor element that match specified pattern. Provided patterns should be compatible with Matcher as it is used internally.

    Parameters

    patterns : Object | String | RegExp | function

    Patterns used to match correct ancestor. See Matcher.

    Returns

    Element | null

    Found element or null if no matching ancestor was found.

    Related:

  • getAncestors( options = { [options.includeSelf], [options.parentFirst] } ) → Array

    inherited

    Returns ancestors array of this node.

    Parameters

    options : Object

    Options object.

    Properties
    [ options.includeSelf ] : Boolean

    When set to true this node will be also included in parent's array.

    Defaults to false

    [ options.parentFirst ] : Boolean

    When set to true, array will be sorted from node's parent to root element, otherwise root element will be the first item in the array.

    Defaults to false

    Returns

    Array

    Array with ancestors.

  • getAttribute( key ) → String | undefined

    inherited

    Gets attribute by key. If attribute is not present - returns undefined.

    Parameters

    key : String

    Attribute key.

    Returns

    String | undefined

    Attribute value.

  • getAttributeKeys() → Iterable.<String>

    inherited

    Returns an iterator that contains the keys for attributes. Order of inserting attributes is not preserved.

    Returns

    Iterable.<String>

    Keys for attributes.

  • getAttributes() → Iterable.<*>

    inherited

    Returns iterator that iterates over this element'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.<*>
  • getChild( index ) → Node

    inherited

    Gets child at the given index.

    Parameters

    index : Number

    Index of child.

    Returns

    Node

    Child node.

  • getChildIndex( node ) → Number

    inherited

    Gets index of the given child node. Returns -1 if child node is not found.

    Parameters

    node : Node

    Child node.

    Returns

    Number

    Index of the child node.

  • getChildren() → Iterable.<Node>

    inherited

    Gets child nodes iterator.

    Returns

    Iterable.<Node>

    Child nodes iterator.

  • getClassNames() → Iterable.<String>

    inherited

    Returns iterator that contains all class names.

    Returns

    Iterable.<String>
  • getCommonAncestor( node, options = { [options.includeSelf] } ) → Element | DocumentFragment | null

    inherited

    Returns a Element or DocumentFragment which is a common ancestor of both nodes.

    Parameters

    node : Node

    The second node.

    options : Object

    Options object.

    Properties
    [ options.includeSelf ] : Boolean

    When set to true both nodes will be considered "ancestors" too. Which means that if e.g. node A is inside B, then their common ancestor will be B.

    Defaults to false

    Returns

    Element | DocumentFragment | null
  • getCustomProperties() → Iterable.<*>

    inherited

    Returns an iterator which iterates over this element's custom properties. Iterator provides [ key, value ] pairs for each stored property.

    Returns

    Iterable.<*>
  • getCustomProperty( key ) → *

    inherited

    Returns the custom property value for the given key.

    Parameters

    key : String | Symbol

    Returns

    *
  • getFillerOffset() → null

    Returns null because filler is not needed for UIElements.

    Returns

    null

    Always returns null.

  • getIdentity() → String

    inherited

    Returns identity string based on element's name, styles, classes and other attributes. Two elements that are similar will have same identity string. It has the following format:

    'name class="class1,class2" style="style1:value1;style2:value2" attr1="val1" attr2="val2"'

    For example:

    const element = writer.createContainerElement( 'foo', {
        banana: '10',
        apple: '20',
        style: 'color: red; border-color: white;',
        class: 'baz'
    } );
    
    // returns 'foo class="baz" style="border-color:white;color:red" apple="20" banana="10"'
    element.getIdentity();

    NOTE: Classes, styles and other attributes are sorted alphabetically.

    Returns

    String
  • getPath() → Array.<Number>

    inherited

    Gets a path to the node. The path is an array containing indices of consecutive ancestors of this node, beginning from root, down to this node's index.

    const abc = downcastWriter.createText( 'abc' );
    const foo = downcastWriter.createText( 'foo' );
    const h1 = downcastWriter.createElement( 'h1', null, downcastWriter.createText( 'header' ) );
    const p = downcastWriter.createElement( 'p', null, [ abc, foo ] );
    const div = downcastWriter.createElement( 'div', null, [ h1, p ] );
    foo.getPath(); // Returns [ 1, 3 ]. `foo` is in `p` which is in `div`. `p` starts at offset 1, while `foo` at 3.
    h1.getPath(); // Returns [ 0 ].
    div.getPath(); // Returns [].

    Returns

    Array.<Number>

    The path.

  • getStyle( property ) → String | undefined

    inherited

    Returns style value for given property. Undefined is returned if style does not exist.

    Parameters

    property : String

    Returns

    String | undefined
  • getStyleNames() → Iterable.<String>

    inherited

    Returns iterator that contains all style names.

    Returns

    Iterable.<String>
  • hasAttribute( key ) → Boolean

    inherited

    Returns a boolean indicating whether an attribute with the specified key exists in the element.

    Parameters

    key : String

    Attribute key.

    Returns

    Boolean

    true if attribute with the specified key exists in the element, false otherwise.

  • hasClass( className )

    inherited

    Returns true if class is present. If more then one class is provided - returns true only when all classes are present.

    element.hasClass( 'foo' ); // Returns true if 'foo' class is present.
    element.hasClass( 'foo', 'bar' ); // Returns true if 'foo' and 'bar' classes are both present.

    Parameters

    className : String
  • hasStyle( property )

    inherited

    Returns true if style keys are present. If more then one style property is provided - returns true only when all properties are present.

    element.hasStyle( 'color' ); // Returns true if 'border-top' style is present.
    element.hasStyle( 'color', 'border-top' ); // Returns true if 'color' and 'border-top' styles are both present.

    Parameters

    property : String
  • is( type, [ name ] ) → Boolean

    Checks whether this object is of the given.

    uiElement.is( 'uiElement' ); // -> true
    uiElement.is( 'element' ); // -> true
    uiElement.is( 'node' ); // -> true
    uiElement.is( 'view:uiElement' ); // -> true
    uiElement.is( 'view:element' ); // -> true
    uiElement.is( 'view:node' ); // -> true
    
    uiElement.is( 'model:element' ); // -> false
    uiElement.is( 'documentFragment' ); // -> false

    Assuming that the object being checked is an ui element, you can also check its name:

    uiElement.is( 'span' ); // -> true if this is a span ui element
    uiElement.is( 'uiElement', 'span' ); // -> same as above
    text.is( 'span' ); -> false

    Check the entire list of view objects which implement the is() method.

    Parameters

    type : String

    Type to check when name parameter is present. Otherwise, it acts like the name parameter.

    [ name ] : String

    Element name.

    Returns

    Boolean
  • isAfter( node ) → Boolean

    inherited

    Returns whether this node is after given node. false is returned if nodes are in different trees (for example, in different DocumentFragments).

    Parameters

    node : Node

    Node to compare with.

    Returns

    Boolean
  • isBefore( node ) → Boolean

    inherited

    Returns whether this node is before given node. false is returned if nodes are in different trees (for example, in different DocumentFragments).

    Parameters

    node : Node

    Node to compare with.

    Returns

    Boolean
  • isSimilar( otherElement ) → Boolean

    inherited

    Checks if this element is similar to other element. Both elements should have the same name and attributes to be considered as similar. Two similar elements can contain different set of children nodes.

    Parameters

    otherElement : Element

    Returns

    Boolean
  • render( domDocument ) → HTMLElement

    Renders this UIElement to DOM. This method is called by DomConverter. Do not use inheritance to create custom rendering method, replace render() method instead:

    const myUIElement = downcastWriter.createUIElement( 'span' );
    myUIElement.render = function( domDocument ) {
        const domElement = this.toDomElement( domDocument );
        domElement.innerHTML = '<b>this is ui element</b>';
    
        return domElement;
    };

    Parameters

    domDocument : Document

    Returns

    HTMLElement
  • toDomElement( domDocument ) → HTMLElement

    Creates DOM element based on this view UIElement. Note that each time this method is called new DOM element is created.

    Parameters

    domDocument : Document

    Returns

    HTMLElement
  • toJSON() → Object

    inherited

    Custom toJSON method to solve child-parent circular dependencies.

    Returns

    Object

    Clone of this object with the parent property removed.

  • _addClass( className )

    protected inherited

    Adds specified class.

    element._addClass( 'foo' ); // Adds 'foo' class.
    element._addClass( [ 'foo', 'bar' ] ); // Adds 'foo' and 'bar' classes.

    Parameters

    className : Array.<String> | String

    Fires

    Related:

  • _appendChild( items ) → Number

    protected inherited

    Insert a child node or a list of child nodes at the end of this node and sets the parent of these nodes to this element.

    Parameters

    items : Item | Iterable.<Item>

    Items to be inserted.

    Returns

    Number

    Number of appended nodes.

    Fires

    Related:

  • _clone( [ deep ] ) → Element

    protected inherited

    Clones provided element.

    Parameters

    [ deep ] : Boolean

    If set to true clones element and all its children recursively. When set to false, element will be cloned without any children.

    Defaults to false

    Returns

    Element

    Clone of this element.

  • _fireChange( type, node )

    protected inherited

    Parameters

    type : ChangeType

    Type of the change.

    node : Node

    Changed node.

    Fires

  • _insertChild()

    protected

    Overrides _insertChild method. Throws CKEditorError view-uielement-cannot-add to prevent adding any child nodes to UIElement.

  • _remove()

    protected inherited

    Removes node from parent.

  • _removeAttribute( key ) → Boolean

    protected inherited

    Removes attribute from the element.

    Parameters

    key : String

    Attribute key.

    Returns

    Boolean

    Returns true if an attribute existed and has been removed.

    Fires

    Related:

  • _removeChildren( index, [ howMany ] ) → Array.<Node>

    protected inherited

    Removes number of child nodes starting at the given index and set the parent of these nodes to null.

    Parameters

    index : Number

    Number of the first node to remove.

    [ howMany ] : Number

    Number of nodes to remove.

    Defaults to 1

    Returns

    Array.<Node>

    The array of removed nodes.

    Fires

    Related:

  • _removeClass( className )

    protected inherited

    Removes specified class.

    element._removeClass( 'foo' );  // Removes 'foo' class.
    element._removeClass( [ 'foo', 'bar' ] ); // Removes both 'foo' and 'bar' classes.

    Parameters

    className : Array.<String> | String

    Fires

    Related:

  • _removeCustomProperty( key ) → Boolean

    protected inherited

    Removes the custom property stored under the given key.

    Parameters

    key : String | Symbol

    Returns

    Boolean

    Returns true if property was removed.

    Related:

  • _removeStyle( property )

    protected inherited

    Removes specified style.

    element._removeStyle( 'color' );  // Removes 'color' style.
    element._removeStyle( [ 'color', 'border-top' ] ); // Removes both 'color' and 'border-top' styles.

    Parameters

    property : Array.<String> | String

    Fires

    Related:

  • _setAttribute( key, value )

    protected inherited

    Adds or overwrite attribute with a specified key and value.

    Parameters

    key : String

    Attribute key.

    value : String

    Attribute value.

    Fires

    Related:

  • _setCustomProperty( key, value )

    protected inherited

    Sets a custom property. Unlike attributes, custom properties are not rendered to the DOM, so they can be used to add special data to elements.

    Parameters

    key : String | Symbol
    value : *

    Related:

  • _setStyle( property, [ value ] )

    protected inherited

    Adds style to the element.

    element._setStyle( 'color', 'red' );
    element._setStyle( {
        color: 'red',
        position: 'fixed'
    } );

    Parameters

    property : String | Object

    Property name or object with key - value pairs.

    [ value ] : String

    Value to set. This parameter is ignored if object is provided as the first parameter.

    Fires

    Related:

Events

  • change( eventInfo )

    inherited

    Parameters

    eventInfo : EventInfo

    An object containing information about the fired event.

  • change:attributes( eventInfo, changedNode )

    inherited

    Fired when list of elements attributes changes.

    Change event is bubbled – it is fired on all ancestors.

    Parameters

    eventInfo : EventInfo

    An object containing information about the fired event.

    changedNode : Node
  • change:children( eventInfo, changedNode )

    inherited

    Fired when list of elements children changes.

    Change event is bubbled – it is fired on all ancestors.

    Parameters

    eventInfo : EventInfo

    An object containing information about the fired event.

    changedNode : Node
  • change:text( eventInfo, changedNode )

    inherited

    Fired when text nodes data changes.

    Change event is bubbled – it is fired on all ancestors.

    Parameters

    eventInfo : EventInfo

    An object containing information about the fired event.

    changedNode : Node