Track selection of Dynamic Multiple Choice field

Hi all -

Here is one possible solution if you want to track the selection of choices in a dynamic multiple choice (dMC) field.

In my test DB I have Table2 as my working table. I have a dMC field that points to Table4. I then created a table called child that is a subtable of Table2. In the child table I have the following fields:

Number

Table2 - reference field to Table2 with composition on

Table4 - reference field to Table4

 

Here is the code that I put in the Trigger after update of my dMC field:

let t := this;
let childCnt := count(child);
let dMCcnt := count(numbers(dMC3));
let childArray := child;
let dMCArray := numbers(dMC3);
let diff := if childCnt > dMCcnt then
        let xRec := childArray[(var dt := Table4;
                    count(dMCArray[= dt])) = 0];
        delete child[Table4 = xRec.Table4]
    else
        let xRec := dMCArray[(var dt := this;
                    count(childArray[Table4 = dt])) = 0];
        let newRec := (create child);
        newRec.(
            Number := first(xRec);
            Table4 := first(xRec);
            Table2 := t
        )
    end;

Line 1 gathers the data of the current record.

Line 2 counts the number of records in the child table

Line 3 counts the number of selections in the dMC

Line 4 gathers all of the records from the child table

Line 5 gathers all of the values selected from the dMC field

Line 6 checks to if the count of child is greater than the dMC count. This assumes that there will be a deletion of a record.

Lines 7-8 figures out which record is no longer in the dMC and line 9 deletes that record

Line 10 is the else if dMC count is greater than child so we are assuming a new record needs to be added.

Lines 11 -12 figures out the new record to add.

Lines 13-18 adds the new record.

To see this work, create a new formula field in the main table and add:

child.Table4

You will see the record Id, of the selections made in the dMC field be added and deleted as you select and de-select. As long as you don't manually add records to the child table this will always show you the selection order.

I started off with just a number field that tracks the record Id of the selection from the dMC (that is why I left the number field in the table and in the new record creation), but then I changed it to link a reference field back to Table4, so now you can use that link to gather data from Table4.

I hope this helps someone or spurs some great idea in others.