` (the same attribute key and value). This type of converters is intended to be used with [model element](module_engine_model_element-ModelElement.md) nodes. To convert the text attributes, the [`attributeToElement converter`](#function-attributeToElement)should be set up.
```typescript
// A simple conversion from the `source` model attribute to the `src` view attribute (and vice versa).
editor.conversion.attributeToAttribute( { model: 'source', view: 'src' } );
// Attribute values are strictly specified.
editor.conversion.attributeToAttribute( {
model: {
name: 'imageInline',
key: 'aside',
values: [ 'aside' ]
},
view: {
aside: {
name: 'img',
key: 'class',
value: [ 'aside', 'half-size' ]
}
}
} );
// Set the style attribute.
editor.conversion.attributeToAttribute( {
model: {
name: 'imageInline',
key: 'aside',
values: [ 'aside' ]
},
view: {
aside: {
name: 'img',
key: 'style',
value: {
float: 'right',
width: '50%',
margin: '5px'
}
}
}
} );
// Conversion from and to a model attribute key whose value is an enum (`align=right|center`).
// Use `upcastAlso` to define other view elements that should also be converted to the `align=right` attribute.
editor.conversion.attributeToAttribute( {
model: {
key: 'align',
values: [ 'right', 'center' ]
},
view: {
right: {
key: 'class',
value: 'align-right'
},
center: {
key: 'class',
value: 'align-center'
}
},
upcastAlso: {
right: {
styles: {
'text-align': 'right'
}
},
center: {
styles: {
'text-align': 'center'
}
}
}
} );
```
The `definition.model` parameter specifies which model attribute should be converted from and to. It can be a `{ key, [ values ], [ name ] }` object or a `String`, which will be treated like `{ key: definition.model }`. The `key` property is the model attribute key to convert from and to. The `values` are the possible model attribute values. If the `values` parameter is not set, the model attribute value will be the same as the view attribute value. If `name` is set, the conversion will be set up only for model elements with the given name.
The `definition.view` parameter specifies which view attribute should be converted from and to. It can be a `{ key, value, [ name ] }` object or a `String`, which will be treated like `{ key: definition.view }`. The `key` property is the view attribute key to convert from and to. The `value` is the view attribute value to convert from and to. If `definition.value` is not set, the view attribute value will be the same as the model attribute value. If `key` is `'class'`, `value` can be a `String` or an array of `String`s. If `key` is `'style'`, `value` is an object with key-value pairs. In other cases, `value` is a `String`. If `name` is set, the conversion will be set up only for model elements with the given name. If `definition.model.values` is set, `definition.view` is an object that assigns values from `definition.model.values` to `{ key, value, [ name ] }` objects.
`definition.upcastAlso` specifies which other matching view elements should also be upcast to the given model configuration. If `definition.model.values` is set, `definition.upcastAlso` should be an object assigning values from `definition.model.values` to [`MatcherPattern`](module_engine_view_matcher-MatcherPattern.md)s or arrays of [`MatcherPattern`](module_engine_view_matcher-MatcherPattern.md)s.
**Note:** `definition.model` and `definition.view` form should be mirrored, so the same types of parameters should be given in both parameters.
[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/conversion/conversion.ts#L628)
#### Type parameters
* `TValues: extends string`
#### Parameters
* `definition: object`
The converter definition.
Properties
* `definition.converterPriority?: PriorityString`
* `definition.model: string | object`
The model attribute to convert from and to.
* `definition.upcastAlso?: ArrayOrItem<( string | DowncastAttributeCreatorFunction | (DowncastAttributeDescriptor & { name?: string | undefined; }) )>`
Any view element matching `definition.upcastAlso` will also be converted to the given model attribute. `definition.upcastAlso` is used only if `config.model.values` is specified.
* `definition.view: string | ( DowncastAttributeDescriptor & { name?: string | undefined; } )`
The view attribute to convert from and to.
* `definition.converterPriority?: PriorityString`
* `definition.model: object`
The model attribute to convert from and to.
* `definition.upcastAlso?: RecordFoo
` in the view. ```typescript // A simple conversion from the `paragraph` model element to the `` view element (and vice versa).
editor.conversion.elementToElement( { model: 'paragraph', view: 'p' } );
// Override other converters by specifying a converter definition with a higher priority.
editor.conversion.elementToElement( { model: 'paragraph', view: 'div', converterPriority: 'high' } );
// View specified as an object instead of a string.
editor.conversion.elementToElement( {
model: 'fancyParagraph',
view: {
name: 'p',
classes: 'fancy'
}
} );
// Use `upcastAlso` to define other view elements that should also be converted to a `paragraph` element.
editor.conversion.elementToElement( {
model: 'paragraph',
view: 'p',
upcastAlso: [
'div',
{
// Any element with the `display: block` style.
styles: {
display: 'block'
}
}
]
} );
// `upcastAlso` set as callback enables a conversion of a wide range of different view elements.
editor.conversion.elementToElement( {
model: 'heading',
view: 'h2',
// Convert "heading-like" paragraphs to headings.
upcastAlso: viewElement => {
const fontSize = viewElement.getStyle( 'font-size' );
if ( !fontSize ) {
return null;
}
const match = fontSize.match( /(\d+)\s*px/ );
if ( !match ) {
return null;
}
const size = Number( match[ 1 ] );
if ( size > 26 ) {
// Returned value can be an object with the matched properties.
// These properties will be "consumed" during the conversion.
// See `engine.view.Matcher~MatcherPattern` and `engine.view.Matcher#match` for more details.
return { name: true, styles: [ 'font-size' ] };
}
return null;
}
} );
```
`definition.model` is a `String` with a model element name to convert from or to.
[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-engine/src/conversion/conversion.ts#L304)
#### Parameters
* `definition: object`
The converter definition.
Properties
* `definition.converterPriority?: PriorityString`
* `definition.model: string`
* `definition.upcastAlso?: ArrayOrItem