Get selected records on the grid / datasource

This should also be a common task for Dynamics AX developers.

Fortunately, there's a little helper class in AX to make it easier for us, the MultiSelectionHelper.


For example, if you want to get a set of selected records in a grid, you could use it like this:

MyTableBuffer            myTableBuffer;
MultiSelectionHelper     selectionHelper = MultiSelectionHelper::construct();
Set                      selectedRecords = new Set(Types::Record);


selectionHelper.parmDataSource(myTableBuffer_DS);

myTableBuffer = selectionHelper.getFirst();

while (myTableBuffer)
{
    selectedRecords.add(myTableBuffer);

    myTableBuffer = selectionHelper.getNext();
}

The code above should be very useful when getting the list of selected records directly on the form, but if you want to get the selected records in a class that was called from a form, for example, you could use the MultiSelectionHelper like this:

public static void main(Args _args)
{    
    FormDataSource          formDataSource;    
    MyTableBuffer           myTableBuffer;
    FormRun                 caller = _args.caller();
    MultiSelectionHelper    helper = MultiSelectionHelper::createFromCaller(caller);
    Counter                 i;

    // First we need to get the correct form data source
    for (i = 1; i <= caller.dataSourceCount(); i++)
    {
        formDataSource = caller.dataSource(i);

        if (formDataSource.table() == tableNum(MyTableBuffer))
        {
            break;
        }
    }

    // We then tell the selection helper object to create ranges for the selected records
    helper.createQueryRanges(formDataSource.queryBuildDataSource(), fieldStr(MyTableBuffer, RecId));

    // Now we can traverse the selected records
    myTableBuffer = helper.getFirst();

    while (myTableBuffer)
    {
        info(myTableBuffer.RecId);

        myTableBuffer= helper.getNext();
    }
}

In the example above we received the caller form with the _args object. Then, we have to find the correct FormDataSource object. This should be the table for which we want to get the list of records. After getting the correct data source, we can then tell the selection helper object to create ranges for the selected records on the specified QueryBuildDataSource, which we can now get directly from the FormDataSource in Dynamics AX 2012, with the queryBuildDataSource method. And the last part is the same as the first code example, only this time I didn't add the selected records to a set, I just showed their RecId on the Infolog. Since we need to get the FormDataSource for this latter approach, we can only use it if our form only has one data source for the table we're trying to get.

This should be very useful when you need to perform certain action on a list of selected records. Hope it helps.