# AttributeOperation

class

Operation to change nodes' attribute.

Using this class you can add, remove or change value of the attribute.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/model/operation/attributeoperation.ts#L25)

<a id="properties">

## Properties

<a id="member-affectedSelectable">

### `affectedSelectable: ModelSelectable` _(readonly)_

A selectable that will be affected by the operation after it is executed.

The exact returned parameter differs between operation types.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/model/operation/attributeoperation.ts#L98)

<a id="member-baseVersion">

### `baseVersion: number | null` _(inherited)_

[`version`](module_engine_model_document-ModelDocument.md#member-version) on which operation can be applied. If you try to [apply](module_engine_model_model-Model.md#function-applyOperation) operation with different base version than the [document version](module_engine_model_document-ModelDocument.md#member-version) the [model-document-applyOperation-wrong-version](module_utils_ckeditorerror-CKEditorError.md) error is thrown.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/model/operation/operation.ts#L26)

<a id="member-batch">

### `batch: Batch | null` _(inherited)_

[Batch](module_engine_model_batch-Batch.md) to which the operation is added or `null` if the operation is not added to any batch yet.

Note, that a [non-document operation](#member-isDocumentOperation) has this property always set to `null`, and is never added to any batch.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/model/operation/operation.ts#L40)

<a id="member-isDocumentOperation">

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

Defines whether operation is executed on attached or detached [items](module_engine_model_item-ModelItem.md).

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/model/operation/operation.ts#L31)

<a id="member-key">

### `key: string` _(readonly)_

Key of an attribute to change or remove.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/model/operation/attributeoperation.ts#L38)

<a id="member-newValue">

### `newValue: unknown` _(readonly)_

New value of the attribute with given key or `null`, if operation should remove attribute.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/model/operation/attributeoperation.ts#L52)

<a id="member-oldValue">

### `oldValue: unknown` _(readonly)_

Old value of the attribute with given key or `null`, if attribute was not set before.

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

<a id="member-range">

### `range: ModelRange` _(readonly)_

Range on which operation should be applied.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/model/operation/attributeoperation.ts#L31)

<a id="member-type">

### `type: 'removeAttribute' | 'addAttribute' | 'changeAttribute'` _(readonly)_

Operation type.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/model/operation/attributeoperation.ts#L85)

#### Static properties

<a id="static-member-className">

### `className: string` _(readonly)_

Name of the operation class used for serialization.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/model/operation/attributeoperation.ts#L190)

<a id="methods">

## Methods

<a id="function-constructor">

### `constructor( range, key, oldValue, newValue, baseVersion )`

Creates an operation that changes, removes or adds attributes.

If only `newValue` is set, attribute will be added on a node. Note that all nodes in operation's range must not have an attribute with the same key as the added attribute.

If only `oldValue` is set, then attribute with given key will be removed. Note that all nodes in operation's range must have an attribute with that key added.

If both `newValue` and `oldValue` are set, then the operation will change the attribute value. Note that all nodes in operation's ranges must already have an attribute with given key and `oldValue` as value

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/model/operation/attributeoperation.ts#L73)

#### Parameters

* `range: ModelRange`

  Range on which the operation should be applied. Must be a flat range.

* `key: string`

  Key of an attribute to change or remove.

* `oldValue: unknown`

  Old value of the attribute with given key or `null`, if attribute was not set before.

* `newValue: unknown`

  New value of the attribute with given key or `null`, if operation should remove attribute.

* `baseVersion: number | null`

  Document [`version`](module_engine_model_document-ModelDocument.md#member-version) on which operation can be applied or `null` if the operation operates on detached (non-document) tree.

<a id="function-clone">

### `clone() → AttributeOperation`

Creates and returns an operation that has the same parameters as this operation.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/model/operation/attributeoperation.ts#L105)

#### Returns

* `AttributeOperation`

<a id="function-getReversed">

### `getReversed() → Operation`

See [`Operation#getReversed()`](module_engine_model_operation_operation-Operation.md#function-getReversed).

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/model/operation/attributeoperation.ts#L112)

#### Returns

* `Operation`

<a id="function-toJSON">

### `toJSON() → unknown`

Custom toJSON method to solve child-parent circular dependencies.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/model/operation/attributeoperation.ts#L119)

#### Returns

* `unknown`

  Clone of this object with the operation property replaced with string.

<a id="function-_execute">

### `_execute() → void` _(internal)_

Executes the operation - modifications described by the operation properties will be applied to the model tree.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/model/operation/attributeoperation.ts#L179)

#### Returns

* `void`

<a id="function-_validate">

### `_validate() → void` _(internal)_

Checks whether the operation's parameters are correct and the operation can be correctly executed. Throws an error if operation is not valid.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/model/operation/attributeoperation.ts#L131)

#### Returns

* `void`

#### Static methods

<a id="static-function-fromJSON">

### `fromJSON( json, document ) → AttributeOperation` _(static)_

Creates `AttributeOperation` object from deserialized object, i.e. from parsed JSON string.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/model/operation/attributeoperation.ts#L200)

#### Parameters

* `json: any`

  Deserialized JSON object.

* `document: ModelDocument`

  Document on which this operation will be applied.

#### Returns

* `AttributeOperation`

---

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