Overriding a javascript delivered function but then calling the original

Question

I have a tabular form (updateable report) and am on Apex 3.2.
On this particular form, I have the updateable report set to "partial page refresh = yes". When doing so, it appears to want to call a javascript function called $a_report to paginate from one set of rows to another. I have my pagination set to select-list with row ranges.
Before repagination continues, I would like to do some validation (specifically, see if the user selected any of the checkbox row selectors) and warn them via Javascript's "confirm" box that continuing will make them lose their selections.
I have no issue so far in determining if at least one checkbox is checked and no problem popping up the confirmation box. However, the real issue is that I want to pop up the confirm box and then continue only if the user says they want to continue.
Apex generates this report with the select-list and links to paginate by calling a function in Javascript called "$a_report". Since this is in the library, I cannot really get to it; it's a "black box" to me at runtime. So ideally what I'd like to do is create a local (on my page) javascript function of the same name (since I can't change what the select-list for pagination calls) accepting the same four parameters, do my checkbox validation and warning, and then effectively call the $a_report in the library to do the pagination if the user wants to continue.
As it is right now I got a copy of the code for the function and put it local on my page and then added in my own logic, but of course this means that if $a_report changes in future versions, my local copy might break and would have to be updated. Ideally, I would like to somehow create a locally-named function called $a_report, do my validation and ask for confirmation, and if the user chooses "OK" to continue, call the library one in sort of a "super" or "parent" way to do the pagination.
Is this possible with javascript to create some sort of OOP-like inheritance or some sort of sense of scope so that I can have a local copy and then call the one in the library?
Thanks!

Answer 1

Hi Kramis,
Let's start with a simple example
class OriginalClass
  public void doSomething( )
  System.out.println("This is the Original class's doSomething( ) ");
class InheritedClass extends OriginalClass
  public void doSomething( )
  super.doSonething( );//Watch here you are calling the original method that was declared in OriginalClass
  //Now you are adding some codes of your choice
  System.out.println("This is Inherited class's doSomething( ) ");
Explanation :
When you create an object of type InheritedClass and you call the method doSomething( ) then the original method gets executed first and later the rest of the code written in the InheritedClass 's doSomething( ) method gets executed.I hope this works for you. If you do not want the original to be executed just remove the super.doSomething( ) call.