SecTransformPushbackAttribute(_:_:_:)

Declaration

func SecTransformPushbackAttribute(_ ref: SecTransformImplementationRef, _ attribute: SecTransformStringOrAttribute, _ value: CFTypeRef) -> CFTypeRef?

Parameters

• ref:

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

• attribute:

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

• value:

  The value being pushed back.

Return Value

An error on failure, or NULL on success. In Objective-C, call the CFRelease function to free the error’s memory when you are done with it.

Discussion

Calling this function stops the flow of data into the specified attribute until any attribute is changed for the transform instance bound to the ref parameter.