Dispatcher Component¶
Overview¶
The Phalcon\Mvc\Dispatcher is the component responsible for instantiating controllers and executing the required actions on them in an MVC application. Dispatching is the process of taking the request object, extracting the module name, controller name, action name, and optional parameters contained in it, and then instantiating a controller and calling the action of that controller.
<?php
use Phalcon\Di\Di;
use Phalcon\Mvc\Dispatcher;
$container = new Di();
$dispatcher = new Dispatcher();
$dispatcher->setDI($container);
$dispatcher->setControllerName("posts");
$dispatcher->setActionName("index");
$dispatcher->setParams([]);
$controller = $dispatcher->dispatch();
Methods¶
Calls an action method with a handler and parameters Process the results of the router by calling into the appropriate controller action(s) including any routing data or injected parameters. Returns the dispatched handler class (the Controller for Mvc dispatching or a Task for CLI dispatching) orfalse
if an exception occurred and the operation was stopped by returning false
in the exception handler. Throws an Exception if any uncaught or unhandled exception occurs during the dispatcher process. Forwards the execution flows to another controller/action. <?php
use Phalcon\Events\Event;
use Phalcon\Mvc\Dispatcher;
use App\Back\Bootstrap as Back;
use App\Front\Bootstrap as Front;
$modules = [
"frontend" => [
"className" => Front::class,
"path" => __DIR__ . "/app/Modules/Front/Bootstrap.php",
"metadata" => [
"controllersNamespace" => "App\Front\Controllers",
],
],
"backend" => [
"className" => Back::class,
"path" => __DIR__ . "/app/Modules/Back/Bootstrap.php",
"metadata" => [
"controllersNamespace" => "App\Back\Controllers",
],
],
];
$application->registerModules($modules);
$eventsManager = $container->getShared("eventsManager");
$eventsManager->attach(
"dispatch:beforeForward",
function (
Event $event,
Dispatcher $dispatcher,
array $forward
) use ($modules) {
$metadata = $modules[$forward["module"]]["metadata"];
$dispatcher->setModuleName(
$forward["module"]
);
$dispatcher->setNamespaceName(
$metadata["controllersNamespace"]
);
}
);
// Forward
$this->dispatcher->forward(
[
"module" => "backend",
"controller" => "posts",
"action" => "index",
]
);
<?php
use Phalcon\Mvc\Dispatcher;
/**
* @property Dispatcher $dispatcher
*/
class InvoicesController extends Controller
{
public function viewAction(Invoices $invoice)
{
$boundModels = $this
->dispatcher
->getBoundModels()
;
}
}
public function getParam(
mixed $param,
string | array $filters = null,
mixed $defaultValue = null
): mixed
public function setModelBinder(
BinderInterface $modelBinder,
mixed $cache = null
): DispatcherInterface
$container->set(
'dispatcher',
function() {
$dispatcher = new Dispatcher();
$dispatcher->setModelBinder(
new Binder(),
'cache'
);
return $dispatcher;
}
);
Dispatch Loop¶
This is an important process that has much to do with the MVC flow itself, especially with the controller part. The work occurs within the controller dispatcher. The controller files are read, loaded, and instantiated. Then the required actions are executed. If an action forwards the flow to another controller/action, the controller dispatcher starts again. To better illustrate this, the following example shows approximately the process performed within the Phalcon\Mvc\Dispatcher component.
<?php
$finished = false;
while (true !== $finished) {
$finished = true;
$controllerClass = $controllerName . 'Controller';
$controller = new $controllerClass();
call_user_func_array(
[
$controller,
$actionName . 'Action',
],
$params
);
$finished = true;
}
Forwarding¶
The dispatch loop allows you to forward the execution flow to another controller/action. This is very useful in situations when checking if the user has access to certain areas and if not allowed to be forwarded to other controllers and actions, thus allowing you to reuse code.
<?php
use Phalcon\Mvc\Controller;
use Phalcon\Mvc\Dispatcher;
/**
* @property Dispatcher $dispatcher
*/
class InvoicesController extends Controller
{
public function saveAction($year, $postTitle)
{
// ...
$this->dispatcher->forward(
[
'controller' => 'invoices',
'action' => 'list',
]
);
}
}
NOTE
Keep in mind that performing a forward
is not the same as making an HTTP redirect. Although they produce the same result, performing a forward
will not reload the current page, while the HTTP redirect needs two requests to complete the process.
Examples:
Forward flow to another action in the current controller Forward flow to another action in the current controller, passing parametersA forward
action accepts the following parameters:
Parameter | Description |
---|---|
controller | A valid controller name to forward to. |
action | A valid action name to forward to. |
params | An array of parameters for the action. |
namespace | A valid namespace name where the controller is part of. |
Parameters¶
Preparing¶
By using events or hook points available by the Phalcon\Mvc\Dispatcher, you can easily adjust your application to accept any URL schema that suits your application. This is particularly useful when upgrading your application and want to transform some legacy URLs. For instance, you might want your URLs to be:
Since parameters are passed in the order that they are defined in the URL to actions, you can transform them into the desired schema:
<?php
use Phalcon\Dispatcher;
use Phalcon\Mvc\Dispatcher as MvcDispatcher;
use Phalcon\Events\Event;
use Phalcon\Events\Manager;
$container->set(
'dispatcher',
function () {
$eventsManager = new Manager();
$eventsManager->attach(
'dispatch:beforeDispatchLoop',
function (Event $event, $dispatcher) {
$params = $dispatcher->getParams();
$keyParams = [];
foreach ($params as $index => $value) {
if ($index & 1) {
$key = $params[$index - 1];
$keyParams[$key] = $value;
}
}
$dispatcher->setParams($keyParams);
}
);
$dispatcher = new MvcDispatcher();
$dispatcher->setEventsManager($eventsManager);
return $dispatcher;
}
);
If the desired schema is:
you can use the following code:
<?php
use Phalcon\Dispatcher;
use Phalcon\Events\Event;
use Phalcon\Events\Manager;
use Phalcon\Mvc\Dispatcher as MvcDispatcher;
$container->set(
'dispatcher',
function () {
$eventsManager = new Manager();
$eventsManager->attach(
'dispatch:beforeDispatchLoop',
function (Event $event, $dispatcher) {
$params = $dispatcher->getParams();
$keyParams = [];
foreach ($params as $param) {
$parts = explode(':', $param);
$key = $parts[0];
$value = $parts[1];
$keyParams[$key] = $value;
}
$dispatcher->setParams($keyParams);
}
);
$dispatcher = new MvcDispatcher();
$dispatcher->setEventsManager($eventsManager);
return $dispatcher;
}
);
Getting¶
When a route provides named parameters you can receive them in a controller, a view, or any other component that extends Phalcon\Di\Injectable
<?php
use Phalcon\Mvc\Controller;
use Phalcon\Mvc\Dispatcher;
/**
* @property Dispatcher $dispatcher
*/
class InvoicesController extends Controller
{
public function viewAction()
{
$invoiceId = $this
->dispatcher
->getParam('invoiceId', 'int')
;
$filter = $this
->dispatcher
->getParam('filter', 'string')
;
// ...
}
}
invoiceId
as the first parameter passed and automatically sanitize it as an integer
. The second parameter is the filter
one, which is sanitized as a string
Actions¶
You can also define an arbitrary schema for actions before
the dispatch loop is invoked.
Camelize Names¶
If the original URL is
for example you want to camelize show-unpaid
to ShowUnpaid
, the beforeDispatchLoop
can be used to achieve that.
<?php
use Phalcon\Text;
use Phalcon\Mvc\Dispatcher as MvcDispatcher;
use Phalcon\Events\Event;
use Phalcon\Events\Manager as Manager;
$container->set(
'dispatcher',
function () {
$eventsManager = new Manager();
$eventsManager->attach(
'dispatch:beforeDispatchLoop',
function (Event $event, $dispatcher) {
$dispatcher->setActionName(
Text::camelize(
$dispatcher->getActionName()
)
);
}
);
$dispatcher = new MvcDispatcher();
$dispatcher->setEventsManager($eventsManager);
return $dispatcher;
}
);
Filter File Extensions¶
If the original URL always contains a .php
extension:
You can remove it before dispatching the controller/action combination:
<?php
use Phalcon\Mvc\Dispatcher as MvcDispatcher;
use Phalcon\Events\Event;
use Phalcon\Events\Manager;
$container->set(
'dispatcher',
function () {
$eventsManager = new Manager();
$eventsManager->attach(
'dispatch:beforeDispatchLoop',
function (Event $event, $dispatcher) {
$action = $dispatcher->getActionName();
$action = preg_replace('/\.php$/', '', $action);
$dispatcher->setActionName($action);
}
);
$dispatcher = new MvcDispatcher();
$dispatcher->setEventsManager($eventsManager);
return $dispatcher;
}
);
NOTE
The code above can be used as is or adjusted to help with legacy URL transformations or other use cases where we need to manipulate the action name.
Model Injection¶
There are instances that you might want to inject automatically model instances that have been matched with the parameters passed in the URL.
Our controller is:
<?php
use Phalcon\Mvc\Controller;
use Phalcon\Mvc\View;
/**
* @property View $view
*/
class InvoicesController extends Controller
{
public function viewAction(Invoices $invoice)
{
$this->view->invoice = $invoice;
}
}
viewAction
receives an instance of the model Invoices
. If you try to execute this method without any checks and manipulations, the call will fail. You can however inspect the passed parameters before the dispatch loop and manipulate the parameters accordingly. <?php
use \Exception;
use Phalcon\Events\Event;
use Phalcon\Events\Manager;
use Phalcon\Mvc\Model;
use Phalcon\Mvc\Dispatcher as MvcDispatcher;
use \ReflectionMethod;
$container->set(
'dispatcher',
function () {
$eventsManager = new Manager();
$eventsManager->attach(
'dispatch:beforeDispatchLoop',
function (Event $event, $dispatcher) {
$controllerName = $dispatcher->getControllerClass();
$actionName = $dispatcher->getActiveMethod();
try {
$reflection = new ReflectionMethod(
$controllerName,
$actionName
);
$parameters = $reflection->getParameters();
foreach ($parameters as $parameter) {
$className = $parameter->getClass()->name;
if (is_subclass_of($className, Model::class)) {
$model = $className::findFirstById(
$dispatcher->getParams()[0]
);
$dispatcher->setParams(
[
$model,
]
);
}
}
} catch (Exception $e) {
}
}
);
$dispatcher = new MvcDispatcher();
$dispatcher->setEventsManager($eventsManager);
return $dispatcher;
}
);
The above example has been simplified. You can adjust it according to your needs and inject any kind of dependency or model into an action before it gets executed.
The dispatcher also comes with an option to handle this internally for all models passed into a controller action by using the Phalcon\Mvc\Model\Binder object.
<?php
use Phalcon\Mvc\Dispatcher;
use Phalcon\Mvc\Model\Binder;
$dispatcher = new Dispatcher();
$dispatcher->setModelBinder(
new Binder()
);
return $dispatcher;
NOTE
The Phalcon\Mvc\Model\Binder component uses PHP's Reflection API internally, which consumes additional processing cycles. For that reason, it has the ability to use a cache
instance or a cache service name. To use this feature, you can pass the cache service name or instance as the second argument in the setModelBinder()
method or by just passing the cache instance in the Binder
constructor.
Also, by using the Phalcon\Mvc\Model\Binder\BindableInterface in controllers, you can define the models binding in base controllers.
In the example below, we have a base controller CrudController
which InvoicesController
extends from.
<?php
use Phalcon\Mvc\Controller;
use Phalcon\Mvc\Model;
use Phalcon\Mvc\View;
/**
* @property View $view
*/
class CrudController extends Controller
{
public function viewAction(Model $model)
{
$this->view->model = $model;
}
}
In the InvoicesController
we will define which model the controller is associated with. This is done by implementing the Phalcon\Mvc\Model\Binder\BindableInterface, which will make the getModelName()
method available. This method is used to return the model name. It can return a string with just one model name or an associative array with the key as the parameter name.
<?php
use Phalcon\Mvc\Model\Binder\BindableInterface;
class InvoicesController extends CrudController implements BindableInterface
{
public function getModelName()
{
return Invoices::class;
}
}
By declaring the model associated with the InvoicesController
the binder can check the controller for the getModelName()
method before passing the defined model into the parent view
action.
If your project structure does not use any base controllers, you can of course still bind the model directly into the controller action:
<?php
use Phalcon\Mvc\Controller;
use Phalcon\Mvc\View;
/**
* @property View $view
*/
class InvoicesController extends Controller
{
public function showAction(Invoices $invoice)
{
$this->view->invoice = $invoice;
}
}
NOTE
Currently, the binder will only use the model's primary key to perform a findFirst()
. An example route for the above would be /posts/show/{1}
Not-Found (404)¶
If an Events Manager has been defined, you can use it to intercept exceptions that are thrown when the controller/action pair is not found.
<?php
use Exception;
use Phalcon\Dispatcher;
use Phalcon\Mvc\Dispatcher as MvcDispatcher;
use Phalcon\Events\Event;
use Phalcon\Events\Manager;
use Phalcon\Mvc\Dispatcher\Exception as DispatchException;
$container->setShared(
'dispatcher',
function () {
$eventsManager = new Manager();
$eventsManager->attach(
'dispatch:beforeException',
function (
Event $event,
$dispatcher,
Exception $exception
) {
// 404
if ($exception instanceof DispatchException) {
$dispatcher->forward(
[
'controller' => 'index',
'action' => 'fourOhFour',
]
);
return false;
}
}
);
$dispatcher = new MvcDispatcher();
$dispatcher->setEventsManager($eventsManager);
return $dispatcher;
}
);
or use an alternative syntax checking for the exception.
<?php
use Exception;
use Phalcon\Dispatcher\Exception as DispatcherException;
use Phalcon\Mvc\Dispatcher as MvcDispatcher;
use Phalcon\Events\Event;
use Phalcon\Events\Manager;
$container->setShared(
'dispatcher',
function () {
$eventsManager = new Manager();
$eventsManager->attach(
'dispatch:beforeException',
function (
Event $event,
$dispatcher,
Exception $exception
) {
switch ($exception->getCode()) {
case DispatcherException::EXCEPTION_HANDLER_NOT_FOUND:
case DispatcherException::EXCEPTION_ACTION_NOT_FOUND:
// 404
$dispatcher->forward(
[
'controller' => 'index',
'action' => 'fourOhFour',
]
);
return false;
}
}
);
$dispatcher = new MvcDispatcher();
$dispatcher->setEventsManager($eventsManager);
return $dispatcher;
}
);
We can move this method to a plugin class:
<?php
use Exception;
use Phalcon\Events\Event;
use Phalcon\Mvc\Dispatcher;
use Phalcon\Mvc\Dispatcher\Exception as DispatchException;
class ExceptionsPlugin
{
public function beforeException(
Event $event,
Dispatcher $dispatcher,
Exception $exception
) {
$action = 'fiveOhThree';
if ($exception instanceof DispatchException) {
$action = 'fourOhFour';
}
$dispatcher->forward(
[
'controller' => 'index',
'action' => $action,
]
);
return false;
}
}
NOTE
Only exceptions produced by the dispatcher and exceptions produced in the executed action notify the beforeException
events. Exceptions produced in listeners or controller events are redirected to the latest try/catch.
Events¶
Phalcon\Mvc\Dispatcher is able to send events to a Manager if it is present. Events are triggered using the type dispatch
. Some events when returning boolean false
could stop the active operation. The following events are supported:
Event Name | Triggered | Can stop |
---|---|---|
afterBinding | After models are bound but before executing route | Yes |
afterDispatch | After executing the controller/action method. | Yes |
afterDispatchLoop | After exiting the dispatch loop | No |
afterExecuteRoute | After executing the controller/action method. | No |
afterInitialize | Allow to globally initialize the controller in the request | No |
beforeDispatch | After entering in the dispatch loop. The Dispatcher only knows the information passed by the Router. | Yes |
beforeDispatchLoop | Before entering in the dispatch loop. The Dispatcher only knows the information passed by the Router. | Yes |
beforeException | Before the dispatcher throws any exception | Yes |
beforeExecuteRoute | Before executing the controller/action method. The Dispatcher has initialized the controller and knows if the action exists. | Yes |
beforeForward | Before forwarding to a controller/action method. (MVC Dispatcher) | No |
beforeNotFoundAction | when the action was not found in the controller | Yes |
The INVO sample application, demonstrates how you can take advantage of dispatching events, implementing a security filter with Acl
The following example demonstrates how to attach listeners to this component:
<?php
use Phalcon\Mvc\Dispatcher as MvcDispatcher;
use Phalcon\Events\Event;
use Phalcon\Events\Manager;
$container->set(
'dispatcher',
function () {
$eventsManager = new Manager();
$eventsManager->attach(
'dispatch',
function (Event $event, $dispatcher) {
// ...
}
);
$dispatcher = new MvcDispatcher();
$dispatcher->setEventsManager($eventsManager);
return $dispatcher;
},
true
);
An instantiated controller automatically acts as a listener for dispatch events, so you can implement methods as callbacks:
<?php
use Phalcon\Mvc\Controller;
use Phalcon\Mvc\Dispatcher;
class InvoicesController extends Controller
{
public function beforeExecuteRoute(
Dispatcher $dispatcher
) {
// ...
}
public function afterExecuteRoute(
Dispatcher $dispatcher
) {
// ...
}
}
NOTE
Methods on event listeners accept a Phalcon\Events\Event object as their first parameter - methods in controllers do not.
Events Manager¶
You can use the dispatcher::beforeForward
event to change modules and perform redirections more easily.
<?php
use App\Back\Bootstrap;
use Phalcon\Di\Di;
use Phalcon\Events\Manager;
use Phalcon\Mvc\Dispatcher;
use Phalcon\Events\Event;
$container = new Di();
$modules = [
'backend' => [
'className' => Bootstrap::class,
'path' => '/app/Modules/Back/Bootstrap.php',
'metadata' => [
'controllersNamespace' => 'App\Back\Controllers',
],
],
];
$manager = new Manager();
$manager->attach(
'dispatch:beforeForward',
function (
Event $event,
Dispatcher $dispatcher,
array $forward
) use ($modules) {
$moduleName = $forward['module'];
$metadata = $modules[$moduleName]['metadata'];
$dispatcher->setModuleName($moduleName);
$dispatcher->setNamespaceName(
$metadata['controllersNamespace']
);
}
);
$dispatcher = new Dispatcher();
$dispatcher->setDI($container);
dispatcher->setManager($manager);
$container->set('dispatcher', $dispatcher);
$dispatcher->forward(
[
'module' => 'backend',
'controller' => 'invoices',
'action' => 'index',
]
);
echo $dispatcher->getModuleName();
Custom¶
The Phalcon\Mvc\DispatcherInterface interface must be implemented to create your own dispatcher.
<?php
namespace MyApp\Mvc
use Phalcon\Mvc\DispatcherInterface;
class MyDispatcher implements DispatcherInterface
{
/**
* Dispatches a handle action taking into account the routing parameters
*/
public function dispatch(): object | bool;
/**
* Forwards the execution flow to another controller/action
*/
public function forward(array $forward): void;
/**
* Gets last dispatched action name
*/
public function getActionName(): string;
/**
* Gets the default action suffix
*/
public function getActionSuffix(): string;
/**
* Returns the active controller in the dispatcher
*/
public function getActiveController(): ControllerInterface;
/**
* Gets last dispatched controller name
*/
public function getControllerName(): string;
/**
* Gets the default handler suffix
*/
public function getHandlerSuffix(): string;
/**
* Returns the latest dispatched controller
*/
public function getLastController(): ControllerInterface;
/**
* Gets a param by its name or numeric index
*
* @param string|array filters
*/
public function getParam($param, $filters = null);
/**
* Gets action params
*/
public function getParams(): array;
/**
* Returns value returned by the latest dispatched action
*/
public function getReturnedValue();
/**
* Check if a param exists
*/
public function hasParam($param): bool;
/**
* Checks if the dispatch loop is finished or has more pending
* controllers/tasks to dispatch
*/
public function isFinished(): bool;
/**
* Sets the action name to be dispatched
*/
public function setActionName(string $actionName): void;
/**
* Sets the default action suffix
*/
public function setActionSuffix(string $actionSuffix): void;
/**
* Sets the default controller suffix
*/
public function setControllerSuffix(string $controllerSuffix);
/**
* Sets the controller name to be dispatched
*/
public function setControllerName(string $controllerName);
/**
* Sets the default action name
*/
public function setDefaultAction(string $actionName): void;
/**
* Sets the default controller name
*/
public function setDefaultController(string $controllerName);
/**
* Sets the default namespace
*/
public function setDefaultNamespace(string $defaultNamespace): void;
/**
* Sets the default suffix for the handler
*/
public function setHandlerSuffix(string $handlerSuffix): void;
/**
* Sets the module name which the application belongs to
*/
public function setModuleName(string $moduleName): void;
/**
* Sets the namespace to which the controller belongs to
*/
public function setNamespaceName(string $namespaceName): void;
/**
* Set a param by its name or numeric index
*
* @param mixed value
*/
public function setParam($param, $value): void;
/**
* Sets action params to be dispatched
*/
public function setParams(array $params): void;
}