Calling a new form method from Extension – using CoC – D365 FO

I had a scenario where I had to call a new method in  one of the fields from Vendor Payment Journal Line.

The new method exists in Extension class of  Vendor Payment journal.(which is a form method). This has to be called in modified method of the field ‘Ledger Dimension’.

The steps are as follows

[ExtensionOf(FormStr(LedgerJournalTransVendPaym))]
final class LedgerJournalTransVendPaymFormExt_Extension
{
     public void newMethod()
    {
     ……………….
    }
}

How do call this method in modified ? you have two choices – Create a event handler for the method or Chain of Commands.

On using event handler, I ended up with error when I tried to call the new method using formRun.

[FormDataFieldEventHandler(formDataFieldStr(LedgerJournalTransVendPaym, LedgerJournalTrans, LedgerDimension), FormDataFieldEventType::Modified)]
public static void LedgerDimension_OnModified(FormDataObject sender, FormDataFieldEventArgs e)
{
     FormDataSource ledgerJournalTrans_ds = sender.datasource();
     FormRun formRun= ledgerJournalTrans_ds.formRun();

      formRun.newMethod();
}

Though I did not get any build errors , when navigating from the form I got the error ‘FormRun doesnot have the method ‘newMethod’.

So I went the latter approach and went ahead with creating Chain of Commands.

[ExtensionOf(formDataFieldStr(LedgerJournalTransVendPaym, LedgerJournalTrans , LedgerDimension))]
final class LedgerJournalTransVendPaymField_Extension
{
    public void modified()
    {
         next modified();

        element.newMethod();
     }

}

Note the syntax of creating the extension class for data field in form.

Thus it is developers option to decide whether to use CoC or Event Handler.