Element (engine/view)
@ckeditor/ckeditor5-engine/src/view/element
View element.
The editing engine does not define a fixed semantics of its elements (it is "DTD-free").
This is why the type of the Element
need to
be defined by the feature developer. When creating an element you should use one of the following methods:
downcastWriter#createContainerElement()
in order to create aContainerElement
,downcastWriter#createAttributeElement()
in order to create aAttributeElement
,downcastWriter#createEmptyElement()
in order to create aEmptyElement
.downcastWriter#createUIElement()
in order to create aUIElement
.downcastWriter#createEditableElement()
in order to create aEditableElement
.
Note that for view elements which are not created from the model, like elements from mutations, paste or
data.set it is not possible to define the type of the element.
In such cases the UpcastWriter#createElement()
method
should be used to create generic view elements.
Filtering
Properties
-
childCount : Number
readonly
Number of element's children.
-
The document instance to which this node belongs.
-
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
Is
true
if there are no nodes inside this element,false
otherwise. -
name : String
readonly
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
Map of attributes, where attributes names are keys and attributes values are values.
-
Array of child nodes.
-
_classes : Set
protected
Set of classes associated with element instance.
-
_customProperties : Map
protected
Map of custom properties. Custom properties can be added to element instance, will be cloned but not rendered into DOM.
-
Normalized styles.
-
_unsafeAttributesToRender : Array.<String>
private readonly
A list of attribute names that should be rendered in the editing pipeline even though filtering mechanisms implemented in the
DomConverter
(for instance,shouldRenderAttribute
) would filter them out.These attributes can be specified as an option when the element is created by the
DowncastWriter
. To check whether an unsafe an attribute should be permitted, use theshouldRenderUnsafeAttribute
method.
Methods
-
constructor( document, name, [ attrs ], [ children ] )
protected
Creates a view element.
Attributes can be passed in various formats:
Parameters
-
findAncestor( patterns ) → Element | null
Returns ancestor element that match specified pattern. Provided patterns should be compatible with Matcher as it is used internally.
-
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
Gets attribute by key. If attribute is not present - returns undefined.
Parameters
key : String
Attribute key.
Returns
String | undefined
Attribute value.
-
getAttributeKeys() → Iterable.<String>
Returns an iterator that contains the keys for attributes. Order of inserting attributes is not preserved.
Returns
Iterable.<String>
Keys for attributes.
-
getAttributes() → Iterable.<*>
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 inNode
constructor.Returns
Iterable.<*>
-
Gets child at the given index.
-
getChildIndex( node ) → Number
Gets index of the given child node. Returns
-1
if child node is not found. -
getChildren() → Iterable.<Node>
Gets child nodes iterator.
Returns
Iterable.<Node>
Child nodes iterator.
-
getClassNames() → Iterable.<String>
Returns iterator that contains all class names.
Returns
Iterable.<String>
-
getCommonAncestor( node, options = { [options.includeSelf] } ) → Element | DocumentFragment | null
inherited
Returns a
Element
orDocumentFragment
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.<*>
Returns an iterator which iterates over this element's custom properties. Iterator provides
[ key, value ]
pairs for each stored property.Returns
Iterable.<*>
-
getCustomProperty( key ) → *
Returns the custom property value for the given key.
Parameters
key : String | Symbol
Returns
*
-
Returns block filler offset or
null
if block filler is not needed. -
getIdentity() → String
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:
For example:
Note: Classes, styles and other attributes are sorted alphabetically.
Returns
String
-
getNormalizedStyle( property ) → Object | String | undefined
Returns a normalized style object or single style value.
For an element with style set to: margin:1px 2px 3em;
will return:
and reading for single style value:
Will return a
2px
string.Note: This method will return normalized values only if a particular style processor rule is enabled. See
StylesMap#getNormalized()
for details.Parameters
property : String
Name of CSS property
Returns
Object | String | undefined
-
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.
Returns
Array.<Number>
The path.
-
getStyle( property ) → String | undefined
Returns style value for the given property mae. If the style does not exist
undefined
is returned.Note: This method can work with normalized style names if a particular style processor rule is enabled. See
StylesMap#getAsString()
for details.For an element with style set to
'margin:1px'
:Parameters
property : String
Returns
String | undefined
-
getStyleNames( [ expand ] ) → Iterable.<String>
Returns iterator that contains all style names.
Parameters
[ expand ] : Boolean
Expand shorthand style properties and return all equivalent style representations.
Defaults to
false
Returns
Iterable.<String>
-
hasAttribute( key ) → Boolean
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 )
Returns true if class is present. If more then one class is provided - returns true only when all classes are present.
Parameters
className : String
-
hasStyle( property )
Returns true if style keys are present. If more then one style property is provided - returns true only when all properties are present.
Parameters
property : String
-
is( type, [ name ] ) → Boolean
Checks whether this object is of the given.
Assuming that the object being checked is an element, you can also check its name:
Check the entire list of view objects which implement the
is()
method.Parameters
type : String
Type to check.
[ 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 differentDocumentFragment
s). -
isAttached() → Boolean
inherited
Returns true if the node is in a tree rooted in the document (is a descendant of one of its roots).
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 differentDocumentFragment
s). -
isSimilar( otherElement ) → Boolean
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.
-
shouldRenderUnsafeAttribute( attributeName ) → Boolean
Decides whether an unsafe attribute is whitelisted and should be rendered in the editing pipeline even though filtering mechanisms like
shouldRenderAttribute
say it should not.Unsafe attribute names can be specified when creating an element via
DowncastWriter
.Parameters
attributeName : String
The name of the attribute to be checked.
Returns
Boolean
-
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
Adds specified class.
-
_appendChild( items ) → Number
protected
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
Returns
Number
Number of appended nodes.
Fires
Related:
-
Clones provided element.
Parameters
[ deep ] : Boolean
If set to
true
clones element and all its children recursively. When set tofalse
, element will be cloned without any children.Defaults to
false
Returns
Element
Clone of this element.
-
_fireChange( type, node )
protected inherited
-
_insertChild( index, items ) → Number
protected
-
_remove()
protected inherited
Removes node from parent.
-
_removeAttribute( key ) → Boolean
protected
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
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
Removes specified class.
-
_removeCustomProperty( key ) → Boolean
protected
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
Removes specified style.
Note: This method can work with normalized style names if a particular style processor rule is enabled. See
StylesMap#remove()
for details.Parameters
property : Array.<String> | String
Fires
Related:
-
_setAttribute( key, value )
protected
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
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.
-
_setStyle( property, [ value ] )
protected
Adds style to the element.
Note: This method can work with normalized style names if a particular style processor rule is enabled. See
StylesMap#set()
for details.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:children( eventInfo, changedNode )
inherited
Fired when list of elements children changes.
-
change:text( eventInfo, changedNode )
inherited
Fired when text nodes data changes.
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