3.3 Step 1: Write the OMG IDL Code

The first step in writing a Oracle Tuxedo CORBA application is to specify all of the CORBA interfaces and their methods using the Object Management Group (OMG) Interface Definition Language (IDL). An interface definition written in OMG IDL completely defines the CORBA interface and fully specifies each operation’s arguments. OMG IDL is a purely declarative language. This means that it contains no implementation details. Operations specified in OMG IDL can be written in and invoked from any language that provides CORBA bindings.

The Simpapp sample application implements the CORBA interfaces listed in the following table.

Table 3-2 CORBA Interfaces for the Simpapp Sample Application

Interface	Description	Operation
SimpleFactory	Creates object references to the Simple object	find_simple ()
Simple	Converts the case of a string	to_upper () to_lower ()

Here is a code snippet that illustrates the simple.idl file that defines the CORBA interfaces in the Simpapp sample application.

#pragma prefix "beasys.com"
interface Simple
{
  // Convert a string to lower case (return a new string)
  string to_lower (in string val);
  // Convert a string to upper case (in place)
  void to_upper (inout string val);
};
interface SimpleFactory
{
  Simple find_simple ();
};