Sets an attribute value on a custom transform.


func SecTransformCustomSetAttribute(_ ref: SecTransformImplementationRef, _ attribute: SecTransformStringOrAttribute, _ type: SecTransformMetaAttributeType, _ value: CFTypeRef?) -> CFTypeRef?



A SecTransformImplementationRef that is bound to an instance of a custom transform.


The name or the attribute handle of the attribute whose value is to be set. When using a name, see Transform Attributes for a list of valid key names.


The type of data to be retrieved for the attribute. See the discussion on SecTransformMetaAttributeType for details.


The new value for the attribute

Return Value

An error on failure, or nil on success.


Unlike the SecTransformSetAttribute(_:_:_:_:) function this function can set attribute values while a transform is executing. These values are limited to the custom transform instance that is bound to the ref parameter.

See Also

Transform Characteristics

func SecTransformGetAttribute(SecTransform, CFString) -> CFTypeRef?

Gets the current value of a transform attribute.

Transform Attributes

Specify the attributes of a transform.

typealias SecTransformAttribute

A direct reference to a security transform attribute.

typealias SecTransformStringOrAttribute

A type that may be either a string or an attribute reference.

enum SecTransformMetaAttributeType

The keys that describe the metadata attributes of transform attributes.