In the last two entries, we examined creating a navigation structure with Zend_Navigation, and then we examined using that structure with the Zend Navigation View Helper. In both discussions, we focused on creating navigation items and menus, and inherently these items were available to all users regardless of access controls. But what happens when you have special areas of your site, say for subscribers or administrators? Controlling access is something that all web developers must do at some point. This is where integration between Zend_Navigation and Zend_Acl comes in.
Some important points about Zend_Acl
Zend_Acl doesn’t follow any particular paradigm with regards to implementation of access control. Instead, much like Zend_Navigation, it works as a standalone component, allowing you to determine when, where and how to implement access control. Personally, I implement access control at the module/controller/action level, but you can choose to do it any way you like.
In the last blog post, we discussed creating Zend_Navigation pages and containers. This is certainly wonderful and exciting, but the reality is that for the most part, Zend_Navigation is a pretty useless component of Zend Framework until you have a way to get the data out of the structure you’ve built. And since navigation is a component of most people’s views, we have a view helper to give us the tools we need.
When inside the view, there is a helper method called navigation() that can be accessed to do pretty much any of the things you need to do with the navigation objects. So let’s get started.
This past week I had the need to integrate Zend_Acl with a navigation and menu system. Unfortunately, the documentation took a couple reads for me to understand how Zend_Navigation worked; given this, I wanted to write a primer that others could use to get started with Zend_Navigation. This is a short guide to how Zend_Navigation works, and how you can use it to improve your application.
Some Critical Vocabulary
There is some critical vocabulary that needs to be understood about Zend_Navigation and its use. For starters, Zend_Navigation makes a distinction between pages and containers. A page is a page in your application, either internal (Mvc) or external (Uri). A container is anything that stores pages. The confusing part of this is that pages are containers in themselves. This allows you to build trees of pages.