I have created ObjectReference attribute for WTPart which refers to WTDocument (other Side class: wt.doc.WTDocument and otherside attribute : number), but in create part wizard this attribute shows as "unassignable". How to to display dropdown list of Document instances?
You can follow below steps.
Just like @Kaushik said, you can create IBA and then hook data utility. I believe when says Data Utility, he is referring to SuggestTextBox.
I recently worked on SuggestTextBox. In this you will have to create a suggestion class (implementing Suggestable interface) which would basically do the query. This class should be registered as a service, This service could be called from suggestTextBox wrapper tag.
Something like this: datautility for a non single-value constraint attribute
In Windchill installation there are some example provided there at http://YOUR_WINDCHILL/Windchill/app/#ptc1/carambola/customization/examples/picker/suggest
I hope this helps you!
If you want to create an association between WTDocument and WTPart, you may take a look at configurables links :