EGL: Sorting Datatable Columns

There are many instances when we need to sort a particular column in a datatable. In this article I am trying to demonstrate one out of thousand options to sort a particular column in EGL.

1. Create a Java Class:
   public class DatatableSorting {
   public List sortAsc(List list) {
   Collections.sort(list);
   return list;
   }
   public List sortDesc(List list) {
   Comparator comparator = Collections.reverseOrder();
   Collections.sort(list, comparator);
   return list;
   }
   }
2. Create EGL External Type:
   ExternalType DatatableSorting type JavaObject
   {JavaName = "DatatableSorting", PackageName = "explore.your.thought.process"}
   function sortAsc(sortableArray String[] inout) returns (String[]);
   function sortDesc(sortableArray String[] inout) returns (String[]);
   End
3. Use DatatableSorting in EGL File:
   program test type BasicProgram {}
   function main()
   sortableArray String[]{"A", "B", "1", "2"};
   sortingDatatableCols DatatableSorting = new DatatableSorting ();
   sortingDatatableCols.sortAsc(sortableArray);
   sortingDatatableCols.sortDesc(sortableArray);
   end
   end

Note: If we notice carefully the java functions sortAsc and sortDesc accepts list as parameter and returns a list. However in out EGL it is actually String[]. This is because in EGL string[] will be generated to list in Java.

I will be writing one more article on sorting multiple columns based on reflection shortly.

Your comments are most welcome.

Regards

Monu