News Feed
Sections




News Archive
Looking for more information on how to do PHP the right way? Check out PHP: The Right Way

DevShed:
PHP and the Law of Demeter
August 16, 2011 @ 10:20:26

On DevShed today there's a new tutorial looking at how to use dependency injection to help prevent you from breaking the "Law of Demeter" in your application's structure.

When [responsibilities aren't well defined for classes], it's a clear symptom of a common issue known as the "Law of Demeter" breakage. In case the name doesn't ring any bells, the "Law of Demeter" (http://en.wikipedia.org/wiki/Law_of_Demeter) - or the Principle of Least Knowledge - is a paradigm that allows to create loosely-coupled classes, based on a simple concept: each class should be designed to work properly using only the dependencies that it really needs.

He talks about how violation of this law (whether you knew you were or not) can lead to some bad coupling practices. He includes a few classes under a SampleApp that handles the interface between a database and the domain model. The violation of the law comes in when the database and service layers are introduced - a fetch the code does to get an adapter from the service locator rather than directly from the database functionality as it should.

There's code for everything included in the post

0 comments voice your opinion now!
lawofdemeter dependency injection tutorial


blog comments powered by Disqus

Similar Posts

Zend Developer Zone: Using the Digg API with PHP and PEAR

Davey Shafik's Blog: DateTime Timestamp Parsing

SitePoint PHP Blog: Installing PHP Extensions on Nitrous.io

SitePoint PHP Blog: Using Google Translate API with PHP

DevShed: Working with the Tidy Library in PHP 5


Community Events

Don't see your event here?
Let us know!


opinion version introduction voicesoftheelephpant library podcast community laravel5 laravel php7 release series interview unittest framework extension language video security api

All content copyright, 2015 PHPDeveloper.org :: info@phpdeveloper.org - Powered by the Solar PHP Framework