Custom Dropdown List [duplicate]

I'm trying to integrate a cutom dropdown in my panel that allows to change between different display types for the created proxy objects.

The script runs without error but the dropdown is not shown in the panel. Also, I get this message in the console pointing to a certain line but I can't figure out what's the problem.

D:\XXXXXXX\XXXXXXXX\XXXXXXXXXX\scripting 2_8 wip.blend\Create Proxy Tools:326 rna_uiItemR: property not found: PROPS_UL_ProxyToolDisplayTypes.DisplayType_List


Edit: Here's a .blend with the script https://1drv.ms/u/s!BH2oRah8e0Ptg8QA9G_pwLDWGUt9ng?e=2yp3rI

• Your formatting is horribly broken. Please fix it, because right now I can't tell what's wrong from copy & pasting and what is actually wrong in your source code. – Robert Gützkow Sep 1 '19 at 17:59
• @rjg Ok😬 what exactly is broken about it. As you can see, I'm not a programer. I just applied what I saw in tutorials. Any tips on proper form would be great – xrogueleaderx Sep 1 '19 at 19:14
• No problem. I was talking just about the formatting in your post. Linebreaks and indentation. Haven't tested it yet. – Robert Gützkow Sep 1 '19 at 19:20
• @rjg ooh, do you also mean just these guys '>'? I think that was caused by copying it out of the text editor... I will provide a clean version as soon as I have acces to a computer. Also, the script worked fine until I added the dropdown related code. I will try to mark that part for you – xrogueleaderx Sep 1 '19 at 19:29
• @brockmann Thanks for this awesome reference. I got it to work perfectly – xrogueleaderx Sep 2 '19 at 15:17