Zend Framework: Controller Plugins vs Action Helpers

Question

Could someone give few tips and/or examples how Controller Plugins and Action Helpers are different? Are there situations where particular task could be accomplished with one but not another? For me they both look more or less the same and I'm often having trouble having to decide when to use what... Are there any big differences?

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Answer 1

Controller plugins can hook into any controller at any point in the routing process (preDispatch postDispatch, routeStartup, routeShutdown) which makes them apt at providing behind the scenes functionality like ACL enforcement.

Action Helpers are for for reusable but optional segments that your controller might need to access (redirector, flashMessenger).

So if you are creating a reusable snippet of code that always needs to execute itself then use a controller plugin, otherwise you probably want an action helper.

Hatty

Just to note that action controllers can also execute themselves as they have preDispatch() and postDispatch() hooks. The ActionHelperBroker is used to control this. – Harm

Answer 2

You can think of it this way:

• Action helpers are used to add methods to controllers.
• Controller plugins are used to add routing / dispatch logic to controllers.

So ask yourself, do I have a method that I would like to be able to call from all actions in my controller? Or do I need to add logic to the routing / dispatch process.

You might also have a look at the the Built in Action Helpers.

Arraign

Answer 3

A picture to illustrate the difference between plugins and action helpers: ZF Sequence Flow

Import

Answer 4

Action helpers also have access to the actual controlller object that's being executed. Controller Plugins only have access to the FrontController, and therefore only the controller and action name.

Which you use depends on what context you need. If you need to access a view object attached to a controller, for example, you will want an Action Helper.

Margerymarget

Answer 5

Also notice that, in the front controller life-cycle process, the plugins get the control(or invoked) first than the action helpers.

Hildagarde