Comments on: PHP Dependency Injection

By: Robert Cooke

Robert Cooke — Sun, 16 May 2010 09:27:47 +0000

Hi,

I’m using the setter injection, because I set up a very general Factory class for accessing my libraries and I wanted to keep that as simple as possible.

After reading this I’m thinking of putting object specific factories between the general Factory and the objects I want to have so I can choose what to use setter/construct.

Thank you,

Robert

By: ajmichels.com

ajmichels.com — Fri, 16 Apr 2010 21:10:42 +0000

[...] AJ Michels on Apr.16, 2010, under Uncategorized Found this article while looking for an open source Dependency Injection engine for PHP. The grammar needs a [...]

By: catchamonkey

catchamonkey — Wed, 17 Mar 2010 19:50:29 +0000

Good article, outlines well something entirely useful and interesting.
Also, just because Zend doesn’t give you a DI container, doesn’t mean you can’t use it in your Zend apps. Just plugin the Symfony component

By: David Nussio

David Nussio — Tue, 16 Feb 2010 14:26:10 +0000

Dave,
If you want to using database with different interface you can inject into the Book a data mapper object (http://martinfowler.com/eaaCatalog/dataMapper.html) instead the Database object.

By: Five (Good) Lessons The Government Teaches Us About Object-Oriented Programming | BrandonSavage.net

Wed, 02 Dec 2009 06:01:56 +0000

[...] who do the work are dumb; instead, the departments themselves are dependent on you giving them (dependency injection) the proper [...]

By: Martijn Dijksterhuis

Martijn Dijksterhuis — Thu, 12 Nov 2009 02:29:22 +0000

Thanks for sharing this. I found a mention of Dependency Injection on Brandon Savage’s PHP blog; but this explains it.

By: Miroslav Nikolov

Miroslav Nikolov — Fri, 30 Oct 2009 14:36:36 +0000

Very useful, thanks.

By: Q&A: Answering Some Questions About Object-Oriented Programming | BrandonSavage.net

Fri, 30 Oct 2009 05:01:13 +0000

[...] I do not know about dependency injection – do you have any links that do not require subscription? I’ll talk about Dependency Injection here. It’s actually a really simple topic. [...]

By: Ryan

Ryan — Wed, 23 Sep 2009 08:07:21 +0000

Dave,

The idea is that database1 and database2 are both the same class, but different objects (instances). We are not trying to write code that will fit with any interface, we only want to work with our interface.

The reason we inject the different databases is because sometimes we are using a production database to pull real data, and other times we are using a mock database to test our code.

Injection leaves it up to US, not the class, to decide which database to use. This gives us much greater long term flexibility as well as makes our objects loosely coupled.

By: Dave

Dave — Thu, 17 Sep 2009 20:02:41 +0000

I understand what’s going on with DI, except this. In the example of using setter injection, Ryan mentioned creating two Book objects. Book1 would have access to database1, and Book2 would have access to database2. There is one lingering question in my mind…

So, database1 and database2 are required to have the same interface? For instance, if you wanted to perform a query on database1, you might call a performQuery() function for retrieving data. With database2, the proper function might be executeQuery(). So, injecting dependencies forces rigid interface standards on the objects that are depended upon?

Or am I totally off base?