Populate a list with custom property dictionary data

Question

So I'm having some trouble wrapping my head around UI lists.

I've got a custom property on my object that stores a list of data like this:

ob["zones"] = [{"id": 1, "name": "foo", ...}, {[...]}]

I'd like to be able to read all of the name properties into the UI list, but can't figure out the best way to do it. There's currently a placeholder list box based off of the example template for material slots in my panel, but that's as far as I've gotten.

Answer 1

Create a CollectionProperty and supply an own class derived from bpy.types.PropertyGroup, in which you define your properties (it already comes with a StringProperty called "name").

In your UIList class, item refers to what you pass to layout.template_list() as 3rd and 4th argument, so the collection. Thus, item.id and item.name refer to entries in the collection Object.zones in the example below:

import bpy
from bpy.props import IntProperty, CollectionProperty
from bpy.types import Panel, UIList


class OBJECT_UL_zones(UIList):
    def draw_item(self, context, layout, data, item, icon, active_data, active_propname, index):
        split = layout.split(0.2)
        split.label(str(item.id))
        split.prop(item, "name", text="", emboss=False, translate=False, icon='BORDER_RECT')


class UIListPanelExample(Panel):
    """Creates a Panel in the Object properties window"""
    bl_label = "UIList Panel"
    bl_idname = "OBJECT_PT_ui_list_example"
    bl_space_type = 'PROPERTIES'
    bl_region_type = 'WINDOW'
    bl_context = "object"

    def draw(self, context):
        layout = self.layout
        ob = context.object

        layout.template_list("OBJECT_UL_zones", "", ob, "zones", ob, "zones_index")


class Zone(bpy.types.PropertyGroup):
    # name = StringProperty()
    id = IntProperty()


def register():
    bpy.utils.register_module(__name__)
    bpy.types.Object.zones = CollectionProperty(type=Zone)
    bpy.types.Object.zones_index = IntProperty()

def unregister():
    bpy.utils.unregister_module(__name__)
    del bpy.types.Object.zones

if __name__ == "__main__":
    register()


    # Add an example entry every time this code is executed
    ob = bpy.context.object
    item = ob.zones.add()
    item.id = len(ob.zones)
    item.name = "Zone " + chr(item.id + 64)

Answer 2

If you want UIList access you are going to have to create a Collection property (See bpy.props), See how rigify addon does this.

This means you'll have to use the higher level collection API functions (instead of assigning a custom-property like this).

(Would be good to make a simple example script for this answer, but reading rigify you can see how its done too - for now hope this helps)