Zend Framework Overview

Fav.or.it creator Nick has explained why he chooses Zend framework among the other PHP5 frameworks.

Is it a framework?

The first thing that I always have to explain when talking about the Zend Framework is that to me it is not a ‘framework’ or not in the same way others are frameworks. This causes a lot of confusion and misunderstand of what the Zend Framework has to offer. To me most frameworks require you to conform to how they ‘think’ (something Ruby/Rails suffers from) and breaking out from their thinking requires actual alteration of the framework.

To me the Zend Framework is actually a Library, something that I can pick and choose from and although a good percentage of each module does also interact with other modules this behavior can in most cases be overridden or sub-classed and behaviour changed.

The MVC

Another difference is that a lot of Frameworks revolve around their own implementation of the MVC (Model View Controller) and again if you want to break out from how they work then you may as well not use any of the framework. The Zend Framework does of course include modules that assist in setting up a MVC and it has many great tutorials on ‘the standard’ way of doings things. But once you begin to understand how everything fits together it has incredible power for those who want to stretch its legs.

Not for beginners?

I will at this point make lots of enemies by saying that the Framework is a professional product and is not really for the beginner. Although it has made strides towards simplifying some aspects of the MVC (and other modules) it is still certainly more complex than others and if you have no inclination to do anything ‘out of the ordinary’ then my advice is to use something else.

The Modules

The Zend Framework as I mentioned earlier is made up of a range of modules (full list here) most of which fav.or.it uses at one level or another. I wont go into detail for all of them as I would just be repeating what is said in the manual.

Zend_Acl - Access Control List

I have previous written at length about the ACL and done a podcast on the subject. It is a little hard to get your head around to start off with (the reason I tried to explain it in the PodCast) but it is extremely powerful and versatile.

Zend_Auth - Authentication

Authentication made simple. Although again we have sub-classed and extended the functionality it again got us up and running within hours and then let us think about the more complex tasks by filling in the basics.

Zend_Cache - Caching

The cache is fundamental for anyone who is serious about long term scalability. It allows caching of pages/parts of pages or just raw data. It has two killer features for me 1) Range of backend solutions (File,SQL, Memcache, ZendPlatform) 2) Tagging. The back end options give me great flexibility to choose the right kind of caching for the situation plus it is easy to extend to add your own. The tagging is a delightful way to group together different pieces of information so that they can be cleaned up / listed by tag or tags.

We created a whole new interface so we could view the current state of the various caches we have and allows us to clear out entries by key (every item must have a unique key) or by tag.

For anyone thinking about investing in Zend Platform it also means that when that time comes that any caching can be handed over to the platform.

Zend_Controller / Zend_View

I am a massive fan of well structured MVC’s and the Zend Framework gives me the flexibility to do everything we could possibly want. As default creating mapping between URL & method/controller gives you quick setup. You can then easily extend the routing (how a URL gets translated).

We have a whole set of custom routes, we have a fully sub-classed dispatcher and make use of the helpers when we can.

The Zend_View is quite simple as a starting point but is easily extended and can achieve a range of design patterns. We have various extensions to give us partials and layouts. The partials allow us easy blocks that have local variables assigned to render pages. The layout lets us arrange numbers of blocks/sections.

Zend_Db - Database

I cannot recommend Zend_Db enough! It is at once very simple to get going but fantastically full of depth. I had never considered myself much of a database expert and Zend_Db allowed me to think about the programming problem rather than SQL. The ability to build select statements programmatically with a consistent interface is a dream come true.

Zend_Feed

fav.or.it is all about feed aggregation and Zend_Feed gave us a fantastic head start on consuming and producing feeds. We have sub-classed this heavily as we have a lot of special requirements but it did save us lots of time covering the basics.

Zend_Filter + Zend_Filter_Input + Zend_Validate

I put these all in together as they all have similar tasks. Although at first I found constantly building up filter/validation chains long winded (but very readable) I soon starting building helper functions that let me build the chains with shorter (not sure if clearer) syntax which could then be easily repeated.

e.g.

const FILTER_EXAMPLE = 'Alnum:Alpha:StringTrim';
$string = Filter_Helper::filter(FILTER_EXAMPLE,$string);

The same can be applied for building up Validators. At some point I will release the full syntax and the code.

The Rest

• Zend_Gdata - Easy to use and very powerful, we use it to access blogger services
• Zend_XmlRpc - This is still in its infancy but it still does the job for most tasks
• Zend_Http - Want to perform some custom request? this handles nearly everything, we use it all over the place for a range of tasks and has proved to be very robust
• Zend_Date - Dates come in lots of formats and Zend_Date means you treat them all the same, a few question marks over future performance when over using this
• Zend_Log - Does what it says on the tin, quite lightweight but easily extended to give a few extra features that makes it worthwhile
• Zend_Session - I try and keep clear of over using session data but having the ability to namespace your sessions makes this very useful

Conclusion

The Zend Framework does a fantastic job of giving you a professional quality set of tools to get going with quickly and then when required it doesn’t stop you customizing it when you need to. As you grow more confident and start to understand the underlying reasoning behind the framework you start to work with it more and more and it encourages you to achieve the same kind of extensibility that it has achieved.