Request Flow

Is the process of taking a request and sending a response

1. index.php initiates the Bootstrap
2. Bootstrap loads App, implemented by Magento\Framework\App\Http
3. App loads configuration
4. Routing loops over routes to find a match
5. Controller is page-specific
6. Rendering generates the HTML
7. Flushing Output pushes the HTML to the browser

Init

• Sets up key objects such as index.php and Bootstrap
• Entry points
  • index.php
  • pub/index.php
  • pub/cron.php
  • pub/static.php
  • shell

Routing

• Defines available routers
• Converts URLs into Magent-style ones
• Parses request parameters
• Identifies action classes

Routers

• Routers handle certain URL types
• The router defines its types itself
• Responsible for identifying a URL pattern
• A route is a module's pages, as defined in the module's etc/routes.xml
• Routers are loaded in the following order:
  • Magento\Framework\App\Router\Base
  • Magento\Cms\Controller\Router
  • Magento\UrlRewrite\Controller\Router
  • Magento\Framework\App\Router\DefaultRouter
• Magento\Framework\App\RouterInterface contains only public function match()
• Adding a new Router is done by adding a new parameter to \Magento\Framework\App\RouterList using DI
• Nonstandard routers are converted using the Request object's:
  • setModuleName($name)
  • setControllerName($name)
  • setActionName($name)
  • setParams($name, $value)

Controllers

• execute() method is the entry point
• Handles the request parameters
• Starts the rendering process
• Sometimes instantiates models
• Parameters are available with $this->getRequest()->getParam('name')

Rendering

• Includes templates within a class
• Caches use the ob_* functions
• Classes used:
  • Controller::execute() returns a result object
  • Router::match() returns a result object
  • FrontController::dispatch() dispatches a request and gets a result object
  • App::launch() copies the HTML to the result object
  • Bootstrap::run() flushes the result's HTML to the browser

Front Controllers

• Gather routers injected using DI
• Find matchinf routes/routers
• Obtans HTML and populates the response object
• Magento\Framework\App\FrontController implements Magento\Framework\App\FrontControllerInterface contains only public function dispatch()

URL Processing

• magentoinstall.com/frontName/controller/action/params

Controllers

• One controller handles only one action
• Contains both execute() and a constructor for DI
• Can be extended
• Extends Magento\Framework\App\Action\Action > Magento\Framework\App\Action\AbstractAction
• Magento\Framework\App\ActionInterface defines public function dispatch(ReuestInteface $request) and public function getResponse()
• Is called by the dispatch() method, which calls execute()
• Can be customised using either Preferences or Plugins
• Result types:
  • Page (Magento\Framework\View\Result\Page) for HTML rendering
  • JSON (Magento\Controller\Result\Json) for returning JSON
  • Forward (Magento\Controller\Result\Forward) Load a different action without redirect
  • Redirect (Magento\Controller\Result\Redirect) Load a different action with redirect

Admin Controllers

• Extend \Magento\Backend\App\Action > \Magento\Backend\App\AbstractAction
• AbstractAction's dispatch() method checks _isAllowed()
• Contains auxialiary methods _getSession(), _addBreadcrumb(), _addJs(), _addContent(), _addLeft(), _getUrl()

Creating Controllers

routes.xml:

/router/@id=standard
    route/
        @id -- route ID
        @frontName
        module/
            @name -- module name

frontName/subfolder/class

URL Rewrites

• Make URLs simpler and easier to remember
• Used on static, content, category and product pages
• Stored in url_rewrite
• Handled by Magento\UrlRrewrite\Controller\Router