Modern diag_manager: Add a function that determine the type of the va…

…riable (NOAA-GFDL#1197)

* Add a function to get the type of a variable in the diag manager

diag_manager/diag_data.F90

@@ -584,6 +584,30 @@ subroutine fms_add_attribute(this, att_name, att_value)
     end select
   end subroutine fms_add_attribute
 
+  !> @brief gets the type of a variable
+  !> @return the type of the variable (r4,r8,i4,i8,string)
+  function get_var_type(var) &
+  result(var_type)
+    class(*), intent(in) :: var      !< Variable to get the type for
+    integer              :: var_type !< The variable's type
+
+    select type(var)
+    type is (real(r4_kind))
+      var_type = r4
+    type is (real(r8_kind))
+      var_type = r8
+    type is (integer(i4_kind))
+      var_type = i4
+    type is (integer(i8_kind))
+      var_type = i8
+    type is (character(len=*))
+      var_type = string
+    class default
+      call mpp_error(FATAL, "get_var_type:: The variable does not have a supported type. "&
+                           &"The supported types are r4, r8, i4, i8 and string.")
+    end select
+  end function get_var_type
+
   !> @brief Writes out the attributes from an fmsDiagAttribute_type
   subroutine write_metadata(this, fileobj, var_name, cell_methods)
     class(fmsDiagAttribute_type),      intent(inout) :: this          !< Diag attribute type