Lookup, JumpRef, Modified for a form data source field through CoC

 As Ievgen Miroshnikov explained in his old article https://community.dynamics.com/365/financeandoperations/b/ievgensaxblog/posts/d365foe-how-to-override-form-data-source-field-lookup-method, it is much better to override methods directly on a data source field than on its linked form controls.

I just want to re-iterate it and place here code snippets.

• User can add new control using form personalization and this control won’t support overridden logic. It could be critical if you are restricting field lookup values or adding validations.
• One form could have several controls that refers to one data source field so you have to duplicate your code.
• Number of delegates are limited as well.

So, say we need to implement Lookup, JumpRef, and Modified methods for a custom field on CustInvoiceTable data source of CustFreeInvoice form. Implement these three aforementioned methods, e.g., directly in an extension to the form class.

 

[ExtensionOf(formStr(CustFreeInvoice))]
final class myCustFreeInvoice_Form_Extension
{
    public void myAssignedBankAccountIdModified(FormDataObject _targetField)
    {

       <logic>
    }

    public void myAssignedBankAccountIdJumpRef(FormDataObject _targetField)
    {

       <logic>
    }

    // Different parameter here!

    public void myAssignedBankAccountIdLookup(FormStringControl _callingControl)
    {
       <logic>
    }

Now simply override them for the field when the data source is initialized.

 

public class myCustFreeInvoice_Form_EventHandler
{
    [FormDataSourceEventHandler(formDataSourceStr(CustFreeInvoice, CustInvoiceTable), FormDataSourceEventType::Initialized)]
    public static void myCustInvoiceTable_OnInitialized(FormDataSource _sender, FormDataSourceEventArgs _e)
    {
        FormRun         eogFormRun                  = _sender.formRun();
        FormDataObject  eogCustomField              = _sender.object(fieldNum(CustInvoiceTable, eogCustomField));

        fdoEOGAssignedBankAccountId.registerOverrideMethod(methodStr(FormDataObject, jumpRef), formMethodStr(CustFreeInvoice, myAssignedBankAccountIdJumpRef), myFormRun);
        fdoEOGAssignedBankAccountId.registerOverrideMethod(methodStr(FormDataObject, lookup), formMethodStr(CustFreeInvoice, myAssignedBankAccountIdLookup), myFormRun);
        fdoEOGAssignedBankAccountId.registerOverrideMethod(methodStr(FormDataObject, modified), formMethodStr(CustFreeInvoice, myAssignedBankAccountIdModified), myFormRun);
    }