A.2 An example COM server and client

A.2.4 Creating the client

Now we create the actual client application.

: 1. Choose File > New... from the main window.
: 2. Select Project and click OK.
: The New Project wizard appears.
: 3. In the Project Type section, select "Console Application (EXE)" and click Next to continue to the next wizard page.
: 4. Name the project RotNExample-client.
: 5. Choose a suitable Location for the project.
: 6. Make sure the "Include any available templates" option is not chosen.
: 7. Click Next.
: 8. Choose the Simple libraries option, and choose the "Standard IO streams and string formatting" and "OLE Automation" options.
: 9. Proceed to the last page of the wizard and click Finish.
: 10. In the new project, edit library.dylan, and add to the define library declaration the following line:

use RotNExample-client-stubs;

: 11. Add the same line to the define module declaration in module.dylan.

We now add code to make the client encrypt and decrypt a simple string with the default key of 13 and with the key set to 3.

Note: The remainder of this section of the example involves adding code to RotNExample-client.dylan. A version of this file with all the code we add in this section is available in the Functional Developer installation folder, under Examples\Documentation\RotNExample\RotNExample-client.dylan. You may want to copy that file into place in your project folder rather than typing code in.

: 12. Modify the main method in RotNExample-client.dylan to look like the following.

define method main () => ()
  with-ole
    format-out("Client connecting to server.\n");
    let server = make-RotNExample();
    local method encrypt-and-decrypt () => ()
      let plaintext = "And he was going ooo-la, oooooo-la...";
      format-out("Plaintext is %=, encrypting.\n", plaintext);
      let ciphertext = IRotNExample/encrypt(server, plaintext);
      format-out("Ciphertext is %=, decrypting.\n", ciphertext);
      let decrypted = IRotNExample/decrypt(server, ciphertext);
      format-out("Decrypted text is %=.\n", decrypted);
    end method;

    encrypt-and-decrypt();
    server.IRotNExample/key := 3;
    format-out("Set key to %d.\n", server.IRotNExample/key);
    encrypt-and-decrypt();
    format-out("Client releasing server.\n");
    release(server);
  end with-ole;
end method main;

The with-ole macro initializes OLE at entry and uninitializes it at exit.

: 13. Build the project with Project > Build.
: During the build, you will be prompted for the location of the project file RotNExample-client-stubs.hdp.