Event Mapping: FieldChange

In my post Event Mapping: Extending "Personal Details" in HCM I noted that PeopleTools 8.56 FieldChange event mapping didn't work with fields from subpages. I opened a bug with MyOracle Support and Oracle sent me a fix to test. The fix works great! Now that I have FieldChange Event Mapping working for that prior scenario, I wanted to share how that Personal Details scenario would change. First, I would remove the JavaScriptEvents line. Specifically, these two lines:

REM ** generate the target URL for the new link;
Local string &targetUrl = GenerateComponentPortalURL(%Portal, %Node, MenuName.GH_CUSTOM_FL, %Market, Component.GH_TRAVEL_PREF_FL, Page.GH_TRAVEL_PREF_FL, "");
&recWrk.HCSC_BTN_SELECT.JavaScriptEvents = "href='" | &targetUrl | "'";

Next, I create an Application Class to hold my new FieldChange event mapping PeopleCode:

import PT_RCF:ServiceInterface;

class PersonalDetailsRowClick implements PT_RCF:ServiceInterface
   method execute();
end-class;

method execute
   /+ Extends/implements PT_RCF:ServiceInterface.execute +/
   
   Evaluate HCSC_TAB_DVW.ROW_NUM
   When = 11 /* Travel Preferences  */
      Transfer( False, MenuName.GH_CUSTOM_FL, BarName.USE, ItemName.GH_TRAVEL_PREF_FL, Page.GH_TRAVEL_PREF_FL, %Action_UpdateDisplay);      
   End-Evaluate;
   
end-method;

OK... the code is short and easy to read. Basically, it transfers to another component if a specific condition is met. I believe the confusing part is that condition. The problem that I see is that this code is missing context. Why does that condition exist? What does it mean? Where did that number 11 come from? What is HCSC_TAB_DVW.ROW_NUM? This is a problem I have with Event Mapping. My code is just a fragment with no context. Referring back to the code from Event Mapping: Extending "Personal Details" in HCM, we see that HCSC_TAB_DVW.ROW_NUM is the grid row number. So basically, if the current row clicked is row number 11, then transfer to the specified component.

When writing Event Mapping PeopleCode, it is very important that you understand the base code, the code you are enhancing. The delivered FieldChange event uses an Evaluate statement to transfer based on an identifier that happens to be stored in HCSC_TAB_DVW.ROW_NUM. Oracle is using a row number to choose the target component on click (FieldChange). I followed the same pattern and that pattern led me to number 11. But what if Oracle adds another row? Suddenly my code (or Oracle's code—order matters) breaks. Perhaps I should have used an artificial number such as 100 assuming Oracle would never add 100 items to that "collection"? I can think of few other ways I may have written the initial code that would be easier to follow. For example, what if the code that establishes the rowset also pushed the transfer parameters (menu, bar, item, etc) into fields in the derived work record? Anyways... back to Event Mapping...

The remainder of the configuration is the same as Event Mapping: Extending "Personal Details" in HCM. I create a service definition and map that service definition to the FieldChange event of HCSC_FL_WRK.HCSC_BTN_SELECT. Next step is to choose the Processing Sequence: Pre or Post. I don't have a good answer here. Either way your code will run. If you choose Pre and Oracle adds an eleventh item, then Oracle's code will win. If you chose Post, then your code will win.