PUT behaving like PATCH for nested collections [DATAREST-1012]

Nick Ryan opened DATAREST-1012 and commented

With respect to the documentation at:

5.3. The item resource

it states for "PUT": Replaces the state of the target resource with the supplied request body.

When performing a PUT on a resource which contains a nested collection it invokes the method mergeForPut(...) in DomainObjectReader.java.

Based on the documentation I would expect:

PUT: the nested collection to be replaced rather than merged
PATCH: the nested collection to be merged

QUESTION 1: Is the documentation wrong, or the code wrong or am I misunderstanding the expected behaviour?

Secondary to this is the way this issue was encountered:

If we have a resource which contains a nested collection of polymorphic items:

e.g.

parent has a collection of child where each abstract child could be a concrete boy or girl

when POSTING to modify:

parent.children[0] = boy

to:

parent.children[0] = girl

the code ends up calling mergeForPut(...) and trying to modify a boy instance into a girl instance and I get a message like:

Target bean of type boy is not of type of the persistent entity (girl)!

QUESTION 2: What is the expected behaviour in this case or is this case not supported e.g. for a nested collection of abstract types it needs to be cleared before items of different concrete types are replaced?

Affects: 2.6 GA (Ingalls)

8 votes, 12 watchers