I've noticed that your current version of the Lookup (single, not multiple) uses the Get(id) function for showing the display text of the selected value.
In our case the Lookup is not using a Repository as data source, but instead a web service call is made, whereas user enter some text for a city name in the search box e.g.
user enters: "Amst"
WebService: input: ("Station text") and output: (List of Station code and Station name pairs)
e.g. Amsterdam #87867324, etc...
The value we use as id is the station code and the station name as a display text.
Now we have an issue in the Get(id) function, because we only have a web method for one direction (station name entered, we get station code), but not the other way around. Another issue would be related to performace since we would make to 2 web service
calls unnecessarily because we already get both the name and the code of the station in the first call.
Any suggestion how to resolve this?