Category: programming

How’s this for a post title?

Compare Tool causing a failure, forcing an element restore which results in negating the changes made on the element

Yes, in Dynamics AX, the ERP system I work in every day, using the “compare” tool can destroy your code! Admittedly, it’s an edge case, and it’s not likely to happen terribly often. But still. Compare tools should not actually mess up your code! (Merge tools should, maybe, sometimes. But AX doesn’t even have a merge tool. Don’t get me started…)

So there’s an event I can override, with the following signature:

public void cursorNotify(int _event)

So if I look that up in the documentation, I should be able to see what values I might get for the _event parameter, right? Nope.

It says there’s going to be a table of event IDs, but there is no table.
Go back to the AX 2009 documentation, though, and you can see the table.

And hey, it even has some example code. A lot of the AX 2012 documentation leaves me with the impression that it was automatically generated, and then never reviewed by an actual human. And that they don’t really want to bother updating it or improving it And, sometimes, I feel like I need to vent about that…

Dynamics AX 2012 has a nice class called RecordSortedList, which can be used to create a list of records from a database table. It can be useful when you need to pass a list of records into a method, or return a list of records from a method.

I honestly haven’t used it that often, but I had a case today where I thought it would be perfect. I had a method that currently returns a single record from a table, but that needed to be changed to return a short list of records.

I wrote some code to insert records into the list, then another bit to loop through the list and do something with the records in it. I was puzzled that, while I was definitely inserting multiple records into the list, I was only getting a single record back out. After some trial and error, I discovered that the methods to retrieve records from the list don’t really work right if you fail to explicitly set a sort order on the list. I wasn’t really concerned with sort order, so I didn’t bother setting one at first. Once I set a sort order, everything worked fine.

If you want to see this quirk for yourself, run the test job below with and without the sortOrder() call. As far as I can tell, this isn’t actually documented anywhere, so I thought I’d write up this blog post, as a reminder for myself, and as a resource for anyone else who happens to stumble across this little quirk.

// https://gist.github.com/andyhuey/84495f8a3480d2df31f9
static void AjhTestRSL(Args _args)
{
    CustTable custTable;
    RecordSortedList myList = new RecordSortedList(tableNum(CustTable));
    boolean moreRecs;

    myList.sortOrder(fieldNum(CustTable, AccountNum));

    // create a list
    while select firstOnly10 * from custTable
    {
        myList.ins(custTable);
    }

    // step through the list
    moreRecs = myList.first(custTable);
    while (moreRecs)
    {
        info(custTable.AccountNum);
        moreRecs = myList.next(custTable);
    }
}