# ViewDocumentFragment

class

Document fragment.

To create a new document fragment instance use the [`ViewUpcastWriter#createDocumentFragment()`](module_engine_view_upcastwriter-ViewUpcastWriter.md#function-createDocumentFragment) method.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/documentfragment.ts#L30)

<a id="properties">

## Properties

<a id="member-childCount">

### `childCount: number` _(readonly)_

Number of child nodes in this document fragment.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/documentfragment.ts#L76)

<a id="member-document">

### `document: ViewDocument` _(readonly)_

The document to which this document fragment belongs.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/documentfragment.ts#L34)

<a id="member-getFillerOffset">

### `getFillerOffset: undefined` _(readonly)_

Artificial element getFillerOffset. Returns `undefined`. Added for compatibility reasons.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/documentfragment.ts#L111)

<a id="member-isEmpty">

### `isEmpty: boolean` _(readonly)_

Is `true` if there are no nodes inside this document fragment, `false` otherwise.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/documentfragment.ts#L83)

<a id="member-name">

### `name: undefined` _(readonly)_

Artificial element name. Returns `undefined`. Added for compatibility reasons.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/documentfragment.ts#L104)

<a id="member-parent">

### `parent: null` _(readonly)_

Artificial parent of `DocumentFragment`. Returns `null`. Added for compatibility reasons.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/documentfragment.ts#L97)

<a id="member-root">

### `root: this` _(readonly)_

Artificial root of `DocumentFragment`. Returns itself. Added for compatibility reasons.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/documentfragment.ts#L90)

<a id="member-_children">

### `_children: Array<ViewNode>` _(private)_

Array of child nodes.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/documentfragment.ts#L39)

<a id="member-_customProperties">

### `_customProperties: Map<string | symbol, unknown>` _(private)_

Map of custom properties. Custom properties can be added to document fragment instance.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/documentfragment.ts#L45)

<a id="methods">

## Methods

<a id="function-constructor">

### `constructor( document, children? )` _(internal)_

Creates new DocumentFragment instance.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/documentfragment.ts#L54)

#### Parameters

* `document: ViewDocument`

  The document to which this document fragment belongs.

* `children?: ViewNode | Iterable<ViewNode>`

  A list of nodes to be inserted into the created document fragment.

<a id="function-Symbol.iterator">

### `Symbol.iterator() → Iterator<ViewNode>`

Iterable interface.

Iterates over nodes added to this document fragment.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/documentfragment.ts#L69)

#### Returns

* `Iterator<ViewNode>`

<a id="function-delegate">

### `delegate( events ) → EmitterMixinDelegateChain` _(inherited)_

Delegates selected events to another [`Emitter`](module_utils_emittermixin-Emitter.md). For instance:

```typescript
emitterA.delegate( 'eventX' ).to( emitterB );
emitterA.delegate( 'eventX', 'eventY' ).to( emitterC );
```

then `eventX` is delegated (fired by) `emitterB` and `emitterC` along with `data`:

```typescript
emitterA.fire( 'eventX', data );
```

and `eventY` is delegated (fired by) `emitterC` along with `data`:

```typescript
emitterA.fire( 'eventY', data );
```

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-utils/src/emittermixin.ts#L539)

#### Parameters

* `events: Array<string>`

  Event names that will be delegated to another emitter.

#### Returns

* `EmitterMixinDelegateChain`

<a id="function-fire">

### `fire( eventOrInfo, args ) → GetEventInfo<TEvent>[ 'return' ]` _(inherited)_

Fires an event, executing all callbacks registered for it.

The first parameter passed to callbacks is an [`EventInfo`](module_utils_eventinfo-EventInfo.md) object, followed by the optional `args` provided in the `fire()` method call.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-utils/src/emittermixin.ts#L512)

#### Type parameters

* `TEvent: extends BaseEvent`

  The type describing the event. See [`BaseEvent`](module_utils_emittermixin-BaseEvent.md).

#### Parameters

* `eventOrInfo: GetNameOrEventInfo<TEvent>`

  The name of the event or `EventInfo` object if event is delegated.

* `args: TEvent[ 'args' ]`

  Additional arguments to be passed to the callbacks.

#### Returns

* `GetEventInfo<TEvent>[ 'return' ]`

  By default the method returns `undefined`. However, the return value can be changed by listeners through modification of the [`evt.return`](module_utils_eventinfo-EventInfo.md#member-return)'s property (the event info is the first param of every callback).

<a id="function-getChild">

### `getChild( index ) → ViewNode`

Gets child at the given index.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/documentfragment.ts#L164)

#### Parameters

* `index: number`

  Index of child.

#### Returns

* `ViewNode`

  Child node.

<a id="function-getChildIndex">

### `getChildIndex( node ) → number`

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

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/documentfragment.ts#L174)

#### Parameters

* `node: ViewNode`

  Child node.

#### Returns

* `number`

  Index of the child node.

<a id="function-getChildren">

### `getChildren() → IterableIterator<ViewNode>`

Gets child nodes iterator.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/documentfragment.ts#L183)

#### Returns

* `IterableIterator<ViewNode>`

  Child nodes iterator.

<a id="function-getCustomProperties">

### `getCustomProperties() → Iterable<[ string | symbol, unknown ]>`

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

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/documentfragment.ts#L126)

#### Returns

* `Iterable<[ string | symbol, unknown ]>`

<a id="function-getCustomProperty">

### `getCustomProperty( key ) → unknown`

Returns the custom property value for the given key.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/documentfragment.ts#L118)

#### Parameters

* `key: string | symbol`

#### Returns

* `unknown`

<a id="function-is:ELEMENT">

### `is( type ) → this is ViewElement | ViewAttributeElement | ViewContainerElement | ViewEditableElement | ViewEmptyElement | ViewRawElement | ViewRootEditableElement | ViewUIElement` _(inherited)_

Checks whether this object is of type [`ViewElement`](module_engine_view_element-ViewElement.md) or its subclass.

```typescript
element.is( 'element' ); // -> true
element.is( 'node' ); // -> true
element.is( 'view:element' ); // -> true
element.is( 'view:node' ); // -> true

element.is( 'model:element' ); // -> false
element.is( 'documentSelection' ); // -> false
```

Assuming that the object being checked is an element, you can also check its [name](module_engine_view_element-ViewElement.md#member-name):

```typescript
element.is( 'element', 'img' ); // -> true if this is an <img> element
text.is( 'element', 'img' ); -> false
```

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/typecheckable.ts#L93)

#### Parameters

* `type: 'element' | 'view:element'`

#### Returns

* `this is ViewElement | ViewAttributeElement | ViewContainerElement | ViewEditableElement | ViewEmptyElement | ViewRawElement | ViewRootEditableElement | ViewUIElement`

<a id="function-is:ATTRIBUTE_ELEMENT">

### `is( type ) → this is ViewAttributeElement` _(inherited)_

Checks whether this object is of type [`ViewAttributeElement`](module_engine_view_attributeelement-ViewAttributeElement.md).

```typescript
attributeElement.is( 'attributeElement' ); // -> true
attributeElement.is( 'element' ); // -> true
attributeElement.is( 'node' ); // -> true
attributeElement.is( 'view:attributeElement' ); // -> true
attributeElement.is( 'view:element' ); // -> true
attributeElement.is( 'view:node' ); // -> true

attributeElement.is( 'model:element' ); // -> false
attributeElement.is( 'documentFragment' ); // -> false
```

Assuming that the object being checked is an attribute element, you can also check its [name](module_engine_view_attributeelement-ViewAttributeElement.md#member-name):

```typescript
attributeElement.is( 'element', 'b' ); // -> true if this is a bold element
attributeElement.is( 'attributeElement', 'b' ); // -> same as above
text.is( 'element', 'b' ); -> false
```

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/typecheckable.ts#L130)

#### Parameters

* `type: 'attributeElement' | 'view:attributeElement'`

#### Returns

* `this is ViewAttributeElement`

<a id="function-is:EDITABLE_ELEMENT">

### `is( type ) → this is ViewEditableElement | ViewRootEditableElement` _(inherited)_

Checks whether this object is of type [`ViewEditableElement`](module_engine_view_editableelement-ViewEditableElement.md) or its subclass.

```typescript
editableElement.is( 'editableElement' ); // -> true
editableElement.is( 'element' ); // -> true
editableElement.is( 'node' ); // -> true
editableElement.is( 'view:editableElement' ); // -> true
editableElement.is( 'view:element' ); // -> true
editableElement.is( 'view:node' ); // -> true

editableElement.is( 'model:element' ); // -> false
editableElement.is( 'documentFragment' ); // -> false
```

Assuming that the object being checked is an editbale element, you can also check its [name](module_engine_view_editableelement-ViewEditableElement.md#member-name):

```typescript
editableElement.is( 'element', 'div' ); // -> true if this is a div element
editableElement.is( 'editableElement', 'div' ); // -> same as above
text.is( 'element', 'div' ); -> false
```

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/typecheckable.ts#L187)

#### Parameters

* `type: 'editableElement' | 'view:editableElement'`

#### Returns

* `this is ViewEditableElement | ViewRootEditableElement`

<a id="function-is:CONTAINER_ELEMENT">

### `is( type ) → this is ViewContainerElement | ViewEditableElement | ViewRootEditableElement` _(inherited)_

Checks whether this object is of type [`ViewContainerElement`](module_engine_view_containerelement-ViewContainerElement.md) or its subclass.

```typescript
containerElement.is( 'containerElement' ); // -> true
containerElement.is( 'element' ); // -> true
containerElement.is( 'node' ); // -> true
containerElement.is( 'view:containerElement' ); // -> true
containerElement.is( 'view:element' ); // -> true
containerElement.is( 'view:node' ); // -> true

containerElement.is( 'model:element' ); // -> false
containerElement.is( 'documentFragment' ); // -> false
```

Assuming that the object being checked is a container element, you can also check its [name](module_engine_view_containerelement-ViewContainerElement.md#member-name):

```typescript
containerElement.is( 'element', 'div' ); // -> true if this is a div container element
containerElement.is( 'contaienrElement', 'div' ); // -> same as above
text.is( 'element', 'div' ); -> false
```

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/typecheckable.ts#L158)

#### Parameters

* `type: 'containerElement' | 'view:containerElement'`

#### Returns

* `this is ViewContainerElement | ViewEditableElement | ViewRootEditableElement`

<a id="function-is:RAW_ELEMENT">

### `is( type ) → this is ViewRawElement` _(inherited)_

Checks whether this object is of type [`ViewRawElement`](module_engine_view_rawelement-ViewRawElement.md).

```typescript
rawElement.is( 'rawElement' ); // -> true
rawElement.is( 'element' ); // -> true
rawElement.is( 'node' ); // -> true
rawElement.is( 'view:rawElement' ); // -> true
rawElement.is( 'view:element' ); // -> true
rawElement.is( 'view:node' ); // -> true

rawElement.is( 'model:element' ); // -> false
rawElement.is( 'documentFragment' ); // -> false
```

Assuming that the object being checked is a raw element, you can also check its [name](module_engine_view_rawelement-ViewRawElement.md#member-name):

```typescript
rawElement.is( 'img' ); // -> true if this is an img element
rawElement.is( 'rawElement', 'img' ); // -> same as above
text.is( 'img' ); -> false
```

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/typecheckable.ts#L243)

#### Parameters

* `type: 'rawElement' | 'view:rawElement'`

#### Returns

* `this is ViewRawElement`

<a id="function-is:DOCUMENT_FRAGMENT">

### `is( type ) → this is ViewDocumentFragment` _(inherited)_

hecks whether this object is of type [`ViewDocumentFragment`](module_engine_view_documentfragment-ViewDocumentFragment.md).

```typescript
docFrag.is( 'documentFragment' ); // -> true
docFrag.is( 'view:documentFragment' ); // -> true

docFrag.is( 'model:documentFragment' ); // -> false
docFrag.is( 'element' ); // -> false
docFrag.is( 'node' ); // -> false
```

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/typecheckable.ts#L334)

#### Parameters

* `type: 'documentFragment' | 'view:documentFragment'`

#### Returns

* `this is ViewDocumentFragment`

<a id="function-is:RANGE">

### `is( type ) → this is ViewRange` _(inherited)_

Checks whether this object is of type [`ViewRange`](module_engine_view_range-ViewRange.md).

```typescript
range.is( 'range' ); // -> true
range.is( 'view:range' ); // -> true

range.is( 'model:range' ); // -> false
range.is( 'element' ); // -> false
range.is( 'selection' ); // -> false
```

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/typecheckable.ts#L385)

#### Parameters

* `type: 'range' | 'view:range'`

#### Returns

* `this is ViewRange`

<a id="function-is:POSITION">

### `is( type ) → this is ViewPosition` _(inherited)_

Checks whether this object is of type [`ViewPosition`](module_engine_view_position-ViewPosition.md).

```typescript
position.is( 'position' ); // -> true
position.is( 'view:position' ); // -> true

position.is( 'model:position' ); // -> false
position.is( 'element' ); // -> false
position.is( 'range' ); // -> false
```

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/typecheckable.ts#L369)

#### Parameters

* `type: 'position' | 'view:position'`

#### Returns

* `this is ViewPosition`

<a id="function-is:TEXT_PROXY">

### `is( type ) → this is ViewTextProxy` _(inherited)_

Checks whether this object is of type [`ViewTextProxy`](module_engine_view_textproxy-ViewTextProxy.md).

```typescript
textProxy.is( '$textProxy' ); // -> true
textProxy.is( 'view:$textProxy' ); // -> true

textProxy.is( 'model:$textProxy' ); // -> false
textProxy.is( 'element' ); // -> false
textProxy.is( 'range' ); // -> false
```

**Note:** Until version 20.0.0 this method wasn't accepting `'$textProxy'` type. The legacy `'textProxy'` type is still accepted for backward compatibility.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/typecheckable.ts#L353)

#### Parameters

* `type: '$textProxy' | 'view:$textProxy'`

#### Returns

* `this is ViewTextProxy`

<a id="function-is:TEXT">

### `is( type ) → this is ViewText` _(inherited)_

Checks whether this object is of type [`ViewText`](module_engine_view_text-ViewText.md).

```typescript
text.is( '$text' ); // -> true
text.is( 'node' ); // -> true
text.is( 'view:$text' ); // -> true
text.is( 'view:node' ); // -> true

text.is( 'model:$text' ); // -> false
text.is( 'element' ); // -> false
text.is( 'range' ); // -> false
```

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/typecheckable.ts#L318)

#### Parameters

* `type: '$text' | 'view:$text'`

#### Returns

* `this is ViewText`

<a id="function-is:UI_ELEMENT">

### `is( type ) → this is ViewUIElement` _(inherited)_

Checks whether this object is of type [`ViewUIElement`](module_engine_view_uielement-ViewUIElement.md).

```typescript
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](module_engine_view_uielement-ViewUIElement.md#member-name):

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

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/typecheckable.ts#L300)

#### Parameters

* `type: 'uiElement' | 'view:uiElement'`

#### Returns

* `this is ViewUIElement`

<a id="function-is:ROOT_ELEMENT">

### `is( type ) → this is ViewRootEditableElement` _(inherited)_

Checks whether this object is of type [`ViewRootEditableElement`](module_engine_view_rooteditableelement-ViewRootEditableElement.md).

```typescript
rootEditableElement.is( 'rootElement' ); // -> true
rootEditableElement.is( 'editableElement' ); // -> true
rootEditableElement.is( 'element' ); // -> true
rootEditableElement.is( 'node' ); // -> true
rootEditableElement.is( 'view:editableElement' ); // -> true
rootEditableElement.is( 'view:element' ); // -> true
rootEditableElement.is( 'view:node' ); // -> true

rootEditableElement.is( 'model:element' ); // -> false
rootEditableElement.is( 'documentFragment' ); // -> false
```

Assuming that the object being checked is a root editable element, you can also check its [name](module_engine_view_rooteditableelement-ViewRootEditableElement.md#member-name):

```typescript
rootEditableElement.is( 'element', 'div' ); // -> true if this is a div root editable element
rootEditableElement.is( 'rootElement', 'div' ); // -> same as above
text.is( 'element', 'div' ); -> false
```

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/typecheckable.ts#L272)

#### Parameters

* `type: 'rootElement' | 'view:rootElement'`

#### Returns

* `this is ViewRootEditableElement`

<a id="function-is:EMPTY_ELEMENT">

### `is( type ) → this is ViewEmptyElement` _(inherited)_

Checks whether this object is of type [`ViewEmptyElement`](module_engine_view_emptyelement-ViewEmptyElement.md).

```typescript
emptyElement.is( 'emptyElement' ); // -> true
emptyElement.is( 'element' ); // -> true
emptyElement.is( 'node' ); // -> true
emptyElement.is( 'view:emptyElement' ); // -> true
emptyElement.is( 'view:element' ); // -> true
emptyElement.is( 'view:node' ); // -> true

emptyElement.is( 'model:element' ); // -> false
emptyElement.is( 'documentFragment' ); // -> false
```

Assuming that the object being checked is an empty element, you can also check its [name](module_engine_view_emptyelement-ViewEmptyElement.md#member-name):

```typescript
emptyElement.is( 'element', 'img' ); // -> true if this is a img element
emptyElement.is( 'emptyElement', 'img' ); // -> same as above
text.is( 'element', 'img' ); -> false
```

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/typecheckable.ts#L215)

#### Parameters

* `type: 'emptyElement' | 'view:emptyElement'`

#### Returns

* `this is ViewEmptyElement`

<a id="function-is:SELECTION">

### `is( type ) → this is ViewSelection | ViewDocumentSelection` _(inherited)_

Checks whether this object is of type [`ViewSelection`](module_engine_view_selection-ViewSelection.md) or [`ViewDocumentSelection`](module_engine_view_documentselection-ViewDocumentSelection.md).

```typescript
selection.is( 'selection' ); // -> true
selection.is( 'view:selection' ); // -> true

selection.is( 'model:selection' ); // -> false
selection.is( 'element' ); // -> false
selection.is( 'range' ); // -> false
```

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/typecheckable.ts#L402)

#### Parameters

* `type: 'selection' | 'view:selection'`

#### Returns

* `this is ViewSelection | ViewDocumentSelection`

<a id="function-is:ELEMENT_NAME">

### `is( type, name ) → boolean` _(inherited)_

Checks whether the object is of type [`ViewElement`](module_engine_view_element-ViewElement.md) or its subclass and has the specified `name`.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/typecheckable.ts#L427)

#### Type parameters

* `N: extends string`

#### Parameters

* `type: 'element' | 'view:element'`
* `name: N`

#### Returns

* `boolean`

<a id="function-is:CONTAINER_ELEMENT_NAME">

### `is( type, name ) → boolean` _(inherited)_

Checks whether the object is of type [`ViewContainerElement`](module_engine_view_containerelement-ViewContainerElement.md) or its subclass and has the specified `name`.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/typecheckable.ts#L451)

#### Type parameters

* `N: extends string`

#### Parameters

* `type: 'containerElement' | 'view:containerElement'`
* `name: N`

#### Returns

* `boolean`

<a id="function-is:EMPTY_ELEMENT_NAME">

### `is( type, name ) → boolean` _(inherited)_

Checks whether the object is of type [`ViewEmptyElement`](module_engine_view_emptyelement-ViewEmptyElement.md) has the specified `name`.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/typecheckable.ts#L473)

#### Type parameters

* `N: extends string`

#### Parameters

* `type: 'emptyElement' | 'view:emptyElement'`
* `name: N`

#### Returns

* `boolean`

<a id="function-is:ROOT_ELEMENT_NAME">

### `is( type, name ) → boolean` _(inherited)_

Checks whether the object is of type [`ViewRootEditableElement`](module_engine_view_rooteditableelement-ViewRootEditableElement.md) and has the specified `name`.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/typecheckable.ts#L488)

#### Type parameters

* `N: extends string`

#### Parameters

* `type: 'rootElement' | 'view:rootElement'`
* `name: N`

#### Returns

* `boolean`

<a id="function-is:UI_ELEMENT_NAME">

### `is( type, name ) → boolean` _(inherited)_

Checks whether the object is of type [`ViewUIElement`](module_engine_view_uielement-ViewUIElement.md) and has the specified `name`.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/typecheckable.ts#L495)

#### Type parameters

* `N: extends string`

#### Parameters

* `type: 'uiElement' | 'view:uiElement'`
* `name: N`

#### Returns

* `boolean`

<a id="function-is:RAW_ELEMENT_NAME">

### `is( type, name ) → boolean` _(inherited)_

Checks whether the object is of type [`ViewRawElement`](module_engine_view_rawelement-ViewRawElement.md) and has the specified `name`.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/typecheckable.ts#L480)

#### Type parameters

* `N: extends string`

#### Parameters

* `type: 'rawElement' | 'view:rawElement'`
* `name: N`

#### Returns

* `boolean`

<a id="function-is:EDITABLE_ELEMENT_NAME">

### `is( type, name ) → boolean` _(inherited)_

Checks whether the object is of type [`ViewEditableElement`](module_engine_view_editableelement-ViewEditableElement.md) or its subclass and has the specified `name`.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/typecheckable.ts#L463)

#### Type parameters

* `N: extends string`

#### Parameters

* `type: 'editableElement' | 'view:editableElement'`
* `name: N`

#### Returns

* `boolean`

<a id="function-is:ATTRIBUTE_ELEMENT_NAME">

### `is( type, name ) → boolean` _(inherited)_

Checks whether the object is of type [`ViewAttributeElement`](module_engine_view_attributeelement-ViewAttributeElement.md) and has the specified `name`.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/typecheckable.ts#L443)

#### Type parameters

* `N: extends string`

#### Parameters

* `type: 'attributeElement' | 'view:attributeElement'`
* `name: N`

#### Returns

* `boolean`

<a id="function-is:DOCUMENT_SELECTION">

### `is( type ) → this is ViewDocumentSelection` _(inherited)_

Checks whether this object is of type [`ViewDocumentSelection`](module_engine_view_documentselection-ViewDocumentSelection.md).

```typescript
`docSelection.is( 'selection' ); // -> true
docSelection.is( 'documentSelection' ); // -> true
docSelection.is( 'view:selection' ); // -> true
docSelection.is( 'view:documentSelection' ); // -> true

docSelection.is( 'model:documentSelection' ); // -> false
docSelection.is( 'element' ); // -> false
docSelection.is( 'node' ); // -> false
```

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/typecheckable.ts#L420)

#### Parameters

* `type: 'documentSelection' | 'view:documentSelection'`

#### Returns

* `this is ViewDocumentSelection`

<a id="function-is:NODE">

### `is( type ) → this is ViewText | ViewNode | ViewElement | ViewAttributeElement | ViewContainerElement | ViewEditableElement | ViewEmptyElement | ViewRawElement | ViewRootEditableElement | ViewUIElement` _(inherited)_

Checks whether this object is of type [`ViewNode`](module_engine_view_node-ViewNode.md) or its subclass.

This method is useful when processing view objects that are of unknown type. For example, a function may return a [`ViewDocumentFragment`](module_engine_view_documentfragment-ViewDocumentFragment.md) or a [`ViewNode`](module_engine_view_node-ViewNode.md) that can be either a text node or an element. This method can be used to check what kind of object is returned.

```typescript
someObject.is( 'element' ); // -> true if this is an element
someObject.is( 'node' ); // -> true if this is a node (a text node or an element)
someObject.is( 'documentFragment' ); // -> true if this is a document fragment
```

Since this method is also available on a range of model objects, you can prefix the type of the object with `model:` or `view:` to check, for example, if this is the model's or view's element:

```typescript
viewElement.is( 'view:element' ); // -> true
viewElement.is( 'model:element' ); // -> false
```

By using this method it is also possible to check a name of an element:

```typescript
imgElement.is( 'element', 'img' ); // -> true
imgElement.is( 'view:element', 'img' ); // -> same as above, but more precise
```

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/typecheckable.ts#L57)

#### Parameters

* `type: 'node' | 'view:node'`

#### Returns

* `this is ViewText | ViewNode | ViewElement | ViewAttributeElement | ViewContainerElement | ViewEditableElement | ViewEmptyElement | ViewRawElement | ViewRootEditableElement | ViewUIElement`

<a id="function-listenTo:BASE_EMITTER">

### `listenTo( emitter, event, callback, options? ) → void` _(inherited)_

Registers a callback function to be executed when an event is fired in a specific (emitter) object.

Events can be grouped in namespaces using `:`. When namespaced event is fired, it additionally fires all callbacks for that namespace.

```typescript
// myEmitter.on( ... ) is a shorthand for myEmitter.listenTo( myEmitter, ... ).
myEmitter.on( 'myGroup', genericCallback );
myEmitter.on( 'myGroup:myEvent', specificCallback );

// genericCallback is fired.
myEmitter.fire( 'myGroup' );
// both genericCallback and specificCallback are fired.
myEmitter.fire( 'myGroup:myEvent' );
// genericCallback is fired even though there are no callbacks for "foo".
myEmitter.fire( 'myGroup:foo' );
```

An event callback can [stop the event](module_utils_eventinfo-EventInfo.md#member-stop) and set the [return value](module_utils_eventinfo-EventInfo.md#member-return) of the [`fire`](#function-fire) method.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-utils/src/emittermixin.ts#L475)

#### Type parameters

* `TEvent: extends BaseEvent`

  The type describing the event. See [`BaseEvent`](module_utils_emittermixin-BaseEvent.md).

#### Parameters

* `emitter: Emitter`

  The object that fires the event.

* `event: TEvent[ 'name' ]`

  The name of the event.

* `callback: GetCallback<TEvent>`

  The function to be called on event.

* `options?: GetCallbackOptions<TEvent>`

  Additional options.

#### Returns

* `void`

<a id="function-off">

### `off( event, callback ) → void` _(inherited)_

Stops executing the callback on the given event. Shorthand for [`this.stopListening( this, event, callback )`](#function-stopListening:BASE_STOP).

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-utils/src/emittermixin.ts#L444)

#### Parameters

* `event: string`

  The name of the event.

* `callback: Function`

  The function to stop being called.

#### Returns

* `void`

<a id="function-on">

### `on( event, callback, options? ) → void` _(inherited)_

Registers a callback function to be executed when an event is fired.

Shorthand for [`this.listenTo( this, event, callback, options )`](#function-listenTo:BASE_EMITTER) (it makes the emitter listen on itself).

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-utils/src/emittermixin.ts#L416)

#### Type parameters

* `TEvent: extends BaseEvent`

  The type descibing the event. See [`BaseEvent`](module_utils_emittermixin-BaseEvent.md).

#### Parameters

* `event: TEvent[ 'name' ]`

  The name of the event.

* `callback: GetCallback<TEvent>`

  The function to be called on event.

* `options?: GetCallbackOptions<TEvent>`

  Additional options.

#### Returns

* `void`

<a id="function-once">

### `once( event, callback, options? ) → void` _(inherited)_

Registers a callback function to be executed on the next time the event is fired only. This is similar to calling [`on`](#function-on) followed by [`off`](#function-off) in the callback.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-utils/src/emittermixin.ts#L431)

#### Type parameters

* `TEvent: extends BaseEvent`

  The type descibing the event. See [`BaseEvent`](module_utils_emittermixin-BaseEvent.md).

#### Parameters

* `event: TEvent[ 'name' ]`

  The name of the event.

* `callback: GetCallback<TEvent>`

  The function to be called on event.

* `options?: GetCallbackOptions<TEvent>`

  Additional options.

#### Returns

* `void`

<a id="function-stopDelegating">

### `stopDelegating( event?, emitter? ) → void` _(inherited)_

Stops delegating events. It can be used at different levels:

* To stop delegating all events.
* To stop delegating a specific event to all emitters.
* To stop delegating a specific event to a specific emitter.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-utils/src/emittermixin.ts#L552)

#### Parameters

* `event?: string`

  The name of the event to stop delegating. If omitted, stops it all delegations.

* `emitter?: Emitter`

  (requires `event`) The object to stop delegating a particular event to. If omitted, stops delegation of `event` to all emitters.

#### Returns

* `void`

<a id="function-stopListening:BASE_STOP">

### `stopListening( emitter?, event?, callback? ) → void` _(inherited)_

Stops listening for events. It can be used at different levels:

* To stop listening to a specific callback.
* To stop listening to a specific event.
* To stop listening to all events fired by a specific object.
* To stop listening to all events fired by all objects.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-utils/src/emittermixin.ts#L497)

#### Parameters

* `emitter?: Emitter`

  The object to stop listening to. If omitted, stops it for all objects.

* `event?: string`

  (Requires the `emitter`) The name of the event to stop listening to. If omitted, stops it for all events from `emitter`.

* `callback?: Function`

  (Requires the `event`) The function to be removed from the call list for the given `event`.

#### Returns

* `void`

<a id="function-toJSON">

### `toJSON() → unknown`

Converts `ViewDocumentFragment` instance to plain object and returns it. Takes care of converting all of this document fragment's children.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/documentfragment.ts#L136)

#### Returns

* `unknown`

  `ViewDocumentFragment` instance converted to plain object.

<a id="function-_appendChild">

### `_appendChild( items ) → number` _(internal)_

[Insert](#function-_insertChild) a child node or a list of child nodes at the end and sets the parent of these nodes to this fragment.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/documentfragment.ts#L154)

#### Parameters

* `items: string | ViewItem | Iterable<( string | ViewItem )>`

  Items to be inserted.

#### Returns

* `number`

  Number of appended nodes.

<a id="function-_fireChange">

### `_fireChange( type, node, data? = { data.index } ) → void` _(internal)_

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/documentfragment.ts#L243)

#### Parameters

* `type: ViewDocumentChangeType`

  Type of the change.

* `node: ViewNode | ViewDocumentFragment`

  Changed node.

* `data?: object`

  Additional data.

  Properties

  * `data.index: number`

#### Returns

* `void`

#### Fires

* [change](module_engine_view_node-ViewNode.md#event-change)

<a id="function-_insertChild">

### `_insertChild( index, items ) → number` _(internal)_

Inserts a child node or a list of child nodes on the given index and sets the parent of these nodes to this fragment.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/documentfragment.ts#L196)

#### Parameters

* `index: number`

  Position where nodes should be inserted.

* `items: string | ViewItem | Iterable<( string | ViewItem )>`

  Items to be inserted.

#### Returns

* `number`

  Number of inserted nodes.

<a id="function-_removeChildren">

### `_removeChildren( index, howMany ) → Array<ViewNode>` _(internal)_

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

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/documentfragment.ts#L226)

#### Parameters

* `index: number`

  Number of the first node to remove.

* `howMany: number`

  Number of nodes to remove.

  Defaults to `1`

#### Returns

* `Array<ViewNode>`

  The array of removed nodes.

<a id="function-_removeCustomProperty">

### `_removeCustomProperty( key ) → boolean` _(internal)_

Removes the custom property stored under the given key.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/documentfragment.ts#L264)

#### Parameters

* `key: string | symbol`

#### Returns

* `boolean`

  Returns true if property was removed.

#### Related:

* [ViewDowncastWriter#removeCustomProperty](module_engine_view_downcastwriter-ViewDowncastWriter.md#function-removeCustomProperty)

<a id="function-_setCustomProperty">

### `_setCustomProperty( key, value ) → void` _(internal)_

Sets a custom property. They can be used to add special data to elements.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/view/documentfragment.ts#L253)

#### Parameters

* `key: string | symbol`
* `value: unknown`

#### Returns

* `void`

#### Related:

* [ViewDowncastWriter#setCustomProperty](module_engine_view_downcastwriter-ViewDowncastWriter.md#function-setCustomProperty)

---

Full index of the CKEditor 5 API reference: [llms.txt](llms.txt)