Previous Next

Zend_Controller Basics

The Zend_Controller system is designed to be lightweight, modular, and extensible. It is a minimalist design to permit flexibility and some freedom to users while providing enough structure so that systems built around Zend_Controller share some common conventions and similar code layout.

The following diagram depicts the workflow, and the narrative following describes in detail the interactions:

zend.controller.basics.png

The Zend_Controller workflow is implemented by several components. While it is not necessary to completely understand the underpinnings of all of these components to use the system, having a working knowledge of the process is helpful.

  • Zend_Controller_Front orchestrates the entire workflow of the Zend_Controller system. It is an interpretation of the FrontController pattern. Zend_Controller_Front processes all requests received by the server and is ultimately responsible for delegating requests to ActionControllers (Zend_Controller_Action).

  • Zend_Controller_Request_Abstract (often referred to as the Request Object) represents the request environment and provides methods for setting and retrieving the controller and action names and any request parameters. Additionally it keeps track of whether or not the action it contains has been dispatched by Zend_Controller_Dispatcher. Extensions to the abstract request object can be used to encapsulate the entire request environment, allowing routers to pull information from the request environment in order to set the controller and action names.

    By default, Zend_Controller_Request_Http is used, which provides access to the entire HTTP request environment.

  • Zend_Controller_Router_Interface is used to define routers. Routing is the process of examining the request environment to determine which controller, and action of that controller, should receive the request. This controller, action, and optional parameters are then set in the request object to be processed by Zend_Controller_Dispatcher_Standard. Routing occurs only once: when the request is initially received and before the first controller is dispatched.

    The default router, Zend_Controller_Router_Rewrite, takes a URI endpoint as specified in Zend_Controller_Request_Http and decomposes it into a controller, action, and parameters based on the path information in the url. As an example, the URL http://localhost/foo/bar/key/value would be decoded to use the foo controller, bar action, and specify a parameter key with a value of value.

    Zend_Controller_Router_Rewrite can also be used to match arbitrary paths; see the router documentation for more information.

  • Zend_Controller_Dispatcher_Interface is used to define dispatchers. Dispatching is the process of pulling the controller and action from the request object and mapping them to a controller file/class and action method in the controller class. If the controller or action do not exist, it handles determining default controllers and actions to dispatch.

    The actual dispatching process consists of instantiating the controller class and calling the action method in that class. Unlike routing, which occurs only once, dispatching occurs in a loop. If the request object's dispatched status is reset at any point, the loop will be repeated, calling whatever action is currently set in the request object. The first time the loop finishes with the request object's dispatched status set (boolean true), it will finish processing.

    The default dispatcher is Zend_Controller_Dispatcher_Standard. It defines controllers as MixedCasedClasses ending in the word Controller, and action methods as camelCasedMethods ending in the word Action: FooController::barAction(). In this case, the controller would be referred to as foo and the action as bar.

    Note: CaseNamingConventions

    Since humans are notoriously inconsistent at maintaining case sensitivity when typing links, Zend Framework actually normalizes path information to lowercase. This, of course, will affect how you name your controller and actions... or refer to them in links.

    If you wish to have your controller class or action method name have multiple MixedCasedWords or camelCasedWords, you will need to separate those words on the url with either a '-' or '.' (though you can configure the character used).

    As an example, if you were going to the action in FooBarController::bazBatAction(), you'd refer to it on the url as /foo-bar/baz-bat or /foo.bar/baz.bat.

  • Zend_Controller_Action is the base action controller component. Each controller is a single class that extends the Zend_Controller_Action class and should contain one or more action methods.

  • Zend_Controller_Response_Abstract defines a base response class used to collect and return responses from the action controllers. It collects both headers and body content.

    The default response class is Zend_Controller_Response_Http, which is suitable for use in an HTTP environment.

The workflow of Zend_Controller is relatively simple. A request is received by Zend_Controller_Front, which in turn calls Zend_Controller_Router_Rewrite to determine which controller (and action in that controller) to dispatch. Zend_Controller_Router_Rewrite decomposes the URI in order to set the controller and action names in the request. Zend_Controller_Front then enters a dispatch loop. It calls Zend_Controller_Dispatcher_Standard, passing it the request, to dispatch to the controller and action specified in the request (or use defaults). After the controller has finished, control returns to Zend_Controller_Front. If the controller has indicated that another controller should be dispatched by resetting the dispatched status of the request, the loop continues and another dispatch is performed. Otherwise, the process ends.

Previous Next
Introduction to Zend Framework
Overview
Installation
Zend_Acl
Introduction
Refining Access Controls
Advanced Use
Zend_Auth
Introduction
Database Table Authentication
Digest Authentication
HTTP Authentication Adapter
LDAP Authentication
Open ID Authentication
Zend_Cache
Introduction
The theory of caching
Zend_Cache frontends
Zend_Cache backends
Zend_Captcha
Introduction
Captcha Operation
Captcha Adapters
Zend_Config
Introduction
Theory of Operation
Zend_Config_Ini
Zend_Config_Xml
Zend_Console_Getopt
Introduction to Getopt
Declaring Getopt Rules
Fetching Options and Arguments
Configuring Zend_Console_Getopt
Zend_Controller
Zend_Controller Quick Start
Zend_Controller Basics
The Front Controller
The Request Object
The Standard Router: Zend_Controller_Router_Rewrite
The Dispatcher
Action Controllers
Action Helpers
The Response Object
Plugins
Using a Conventional Modular Directory Structure
MVC Exceptions
Migrating from Previous Versions
Zend_Currency
Introduction to Zend_Currency
How to work with currencies
Migrating from Previous Versions
Zend_Date
Introduction
Theory of Operation
Basic Methods
Zend_Date API Overview
Creation of dates
Constants for General Date Functions
Working examples
Zend_Db
Zend_Db_Adapter
Zend_Db_Statement
Zend_Db_Profiler
Zend_Db_Select
Zend_Db_Table
Zend_Db_Table_Row
Zend_Db_Table_Rowset
Zend_Db_Table Relationships
Zend_Debug
Dumping Variables
Zend_Dojo
Introduction
Zend_Dojo_Data: dojo.data Envelopes
Dojo View Helpers
Dojo Form Elements and Decorators
Zend_Dom
Introduction
Zend_Dom_Query
Zend_Exception
Using Exceptions
Zend_Feed
Introduction
Importing Feeds
Retrieving Feeds from Web Pages
Consuming an RSS Feed
Consuming an Atom Feed
Consuming a Single Atom Entry
Modifying Feed and Entry structures
Custom Feed and Entry Classes
Zend_File
Zend_File_Transfer
Validators for Zend_File_Transfer
Zend_Filter
Introduction
Standard Filter Classes
Filter Chains
Writing Filters
Zend_Filter_Input
Zend_Filter_Inflector
Zend_Form
Zend_Form
Zend_Form Quick Start
Creating Form Elements Using Zend_Form_Element
Creating Forms Using Zend_Form
Creating Custom Form Markup Using Zend_Form_Decorator
Standard Form Elements Shipped With Zend Framework
Standard Form Decorators Shipped With Zend Framework
Internationalization of Zend_Form
Advanced Zend_Form Usage
Zend_Gdata
Introduction to Gdata
Authenticating with AuthSub
Authenticating with ClientLogin
Using Google Calendar
Using Google Documents List Data API
Using Google Spreadsheets
Using Google Apps Provisioning
Using Google Base
Using the YouTube Data API
Using Picasa Web Albums
Catching Gdata Exceptions
Zend_Http
Zend_Http_Client - Introduction
Zend_Http_Client - Advanced Usage
Zend_Http_Client - Connection Adapters
Zend_Http_Cookie and Zend_Http_CookieJar
Zend_Http_Response
Zend_InfoCard
Introduction
Zend_Json
Introduction
Basic Usage
JSON Objects
XML to JSON conversion
Zend_Json_Server - JSON-RPC server
Zend_Layout
Introduction
Zend_Layout Quick Start
Zend_Layout Configuration Options
Zend_Layout Advanced Usage
Zend_Ldap
Introduction
Zend_Loader
Loading Files and Classes Dynamically
Loading Plugins
Zend_Locale
Introduction
Using Zend_Locale
Normalization and Localization
Working with Dates and Times
Supported Languages for Locales
Supported Regions for Locales
Zend_Log
Overview
Writers
Formatters
Filters
Zend_Mail
Introduction
Sending via SMTP
Sending Multiple Mails per SMTP Connection
Using Different Transports
HTML E-Mail
Attachments
Adding Recipients
Controlling the MIME Boundary
Additional Headers
Character Sets
Encoding
SMTP Authentication
Securing SMTP Transport
Reading Mail Messages
Zend_Measure
Introduction
Creation of Measurements
Outputting measurements
Manipulating Measurements
Types of measurements
Zend_Memory
Overview
Memory Manager
Memory Objects
Zend_Mime
Zend_Mime
Zend_Mime_Message
Zend_Mime_Part
Zend_OpenId
Introduction
Zend_OpenId_Consumer Basics
Zend_OpenId_Provider
Zend_Paginator
Introduction
Usage
Configuration
Advanced usage
Zend_Pdf
Introduction.
Creating and loading PDF documents.
Save changes to the PDF document.
Document pages.
Drawing.
Document Info and Metadata.
Zend_Pdf module usage example.
Zend_Registry
Using the Registry
Zend_Rest
Introduction
Zend_Rest_Client
Zend_Rest_Server
Zend_Search_Lucene
Overview
Building Indexes
Searching an Index
Query Language
Query Construction API
Character Set
Extensibility
Interoperating with Java Lucene
Advanced
Best Practices
Zend_Server
Introduction
Zend_Server_Reflection
Zend_Service
Introduction
Zend_Service_Akismet
Zend_Service_Amazon
Zend_Service_Audioscrobbler
Zend_Service_Delicious
Zend_Service_Flickr
Zend_Service_Nirvanix
Zend_Service_ReCaptcha
Zend_Service_Simpy
Introduction
Zend_Service_StrikeIron
Zend_Service_StrikeIron: Bundled Services
Zend_Service_StrikeIron: Advanced Uses
Zend_Service_Technorati
Zend_Service_Yahoo
Zend_Session
Introduction
Basic Usage
Advanced Usage
Global Session Management
Zend_Session_SaveHandler_DbTable
Zend_Soap
Zend_Soap_Server
Zend_Soap_Client
WSDL Accessor
AutoDiscovery. Introduction
Class autodiscovering.
Functions autodiscovering.
Autodiscovering. Datatypes.
Zend_Test
Introduction
Zend_Test_PHPUnit
Zend_Text
Zend_Text_Figlet
Zend_TimeSync
Introduction
Working with Zend_TimeSync
Zend_Translate
Introduction
Adapters for Zend_Translate
Using Translation Adapters
Zend_Uri
Zend_Uri
Zend_Validate
Introduction
Standard Validation Classes
Validator Chains
Writing Validators
Zend_Version
Reading the Zend Framework Version
Zend_View
Introduction
Controller Scripts
View Scripts
View Helpers
Zend_View_Abstract
Zend_Wildfire
Zend_Wildfire
Zend_XmlRpc
Introduction
Zend_XmlRpc_Client
Zend_XmlRpc_Server
Zend Framework Requirements
PHP Version
PHP Extensions
Zend Framework Components
Zend Framework Dependencies
Zend Framework Coding Standard for PHP
Overview
PHP File Formatting
Naming Conventions
Coding Style
Copyright Information