"Table Information" List (Coding Field's Onlookup Trigger)

I did that, but the issue is I can't attach the form to the LookupFormID property of the "Table Information" table because it's virtual, i.e. does not exist, then we can't access its design. Thus, my field's lookup function won't be able to show that form list.

P.S.: I've created this topic on the wrong forum, someone please move it to the "NAV/Navision Classic Client".

I encountered a few problems when programming the field's Onlookup trigger.

I wanted to program the table's field directly, and not the table's form, which would be easier.

I looked up around and I found that I was not the only one facing this issue, as others tried and ended up giving up, some saying it couldn't be done.

But it is possible, I'm just going to explain how to help others.

I had a table (named "Number") with an integer field ("No.") that needed to get its data from the virtual "Table Information" table. Since this is a virtual table, we can't access its design view and fill in the LookupFormID property with the list form we want.

To start, I created a list form for the "Table Information" table called "Table Information List".

Then, in the Onlookup trigger of the "No." field of the "Number" table I coded this:

rNum.RESET; // rNum - Table "Number" Record variable
rNum.SETFILTER("No.",'>1'); // Apply filter

// Runs the form "Table Information List" that I created.
IF FORM.RUNMODAL(FORM::"Table Information List", rNum) = ACTION::LookupOK THEN BEGIN
  VALIDATE("No.", rNum."No."); // Validates and assigns the value of rNum."No." to the "No." field of the "Number" table
END;

The funny part is that if we run the "Number" table the lookup works fine, but it does not store the value of the rNum."No." in the "No." field. Only if, we run the form (another form, this one named "Numbers List") which has "Number" as SourceTable does the looukp work and store values.

Another issue is that, if we have any code, even if it is commented on the Onlookup (control) trigger of the form ("Numbers List"), the lookup stops working.

Thanks for all your help.