Property Update function for properties inside a collection [closed]

Question

I have a PropertyGroup Class called PPP, like the Collection Example on this page: http://www.blender.org/documentation/blender_python_api_2_63_release/bpy.props.html

The problem is that one of the properties in the PPP class, pfloat calls an update function "update_func"

I need to be able to tell which ppp has been changed when the update_func is called, normally you would use self to determine it but that does not seem to work it just returns: PPP("")

Any Ideas / what am I doing wrong?

Answer 1

I can't tell whether it's a known limitation or bug, but it definately returns the reference to the CollectionProperty only.

You need a concept of one element in the collection being "active", e.g. have an IntProperty alongside and use it for a template_list() for instance. Then use that number to get the right item:

self[context.scene.ppp_index].pfloat = 1.23

There's actually a reference to the CollectionProperty item returned,
see https://developer.blender.org/T39798

Answer 2

I have a solution to this problem using Python Lambda.

Create an an update function called "updateID" with inputs for Self,Context and ID

then when creating your property do this:

update = eval("lambda s,c: updateID(s,c,\"%s\")" %foo)

foo is the unique ID that you use to identify that object inside the updateID function like the properties name.

This will create a unique update function for each instance of the property that simply calls the "updateID" function and plums in the ID variable.