Thanks for the nice article :-)

To run your vm in headless mode on Windows you can use:
VBoxHeadless.exe – startvm “My New Development Server”

I also set up some simple batch scripts, vb scripts and shortcuts so that I can start and stop the server and mount a mapped drive to a samba file share running on the server. The vb scripts simply prevent a command prompt from opening while the vm is running:

server_run.bat
“C:\Program Files\VirtualBox\VBoxHeadless.exe” -startvm “My New Development Server”
NET USE V: \\\www /USER: /PERSISTENT:NO

server_run.vbs
Set WshShell = CreateObject(“WScript.Shell”)
WshShell.Run chr(34) & “server_run.bat” & Chr(34), 0
Set WshShell = Nothing

server_stop.bat
“C:\Program Files\VirtualBox\VBoxManage.exe” controlvm “My New Development Server” savestate

server_stop.vbs
Set WshShell = CreateObject(“WScript.Shell”)
WshShell.Run chr(34) & “server_stop.bat” & Chr(34), 0
Set WshShell = Nothing

You can then make shortcuts of the vb scripts and stick them in your Start Menu, Quick Launch, desktop etc. I customised mine to use the vbox icon :)

First, by removing the “Extends” keyword from the class definition we lose inheritance. That means we can no longer extend the functionality of DateTime, but are now simply coupling two different objects together. Second, we don’t have to call the parent constructor at all if we didn’t overload the constructor. We could have simply left the entire constructor out, but for demonstration purposes I left it in to give you an idea of how you could further do any necessary logic upon instantiating the object.

Baz is not trying to create a new class, but merely modify the behavior of the existing object slightly. According to the SOLID OOP principle of Open/Close:

In object-oriented programming, the open/closed principle states “software entities (classes, modules, functions, etc.) should be open for extension, but closed for modification”;[1] that is, such an entity can allow its behaviour to be modified without altering its source code. — Source http://en.wikipedia.org/wiki/Open/closed_principle

Baz is doing two things here. 1) He is following KISS (Keep It Simple Stupid), 2) He is complying with the Open/Close SOLID OOP principle and thus he doesn’t have to worry about how the DateTime object is being used elsewhere since it still complies with all of the other SOLID OOP principles (including the Liskov substitution principle – which is a design by contract).

Your suggestions would actually break the code entirely and defy the purpose since Baz intends for this to work with the existing DateTime objects being used throughout the code (i.e. any dates retrieved from the database and stored as datetime objects throughout).

Baz did his job perfectly and shouldn’t have done it any other way.

The best way to go will be to create a wrapper. The code only requires two changes, then:

1) Remove ” Extends DateTime”.
2) Use “new DateTime(” instead of “new parent(” in the constructor.

Greetings to all