Micro Application¶

Overview¶

Phalcon offers a very 'thin' application, so that you can create Micro applications with minimal PHP code and overhead. Micro applications are suitable for small applications that will have very low overhead. Such applications are usually APIs, prototypes etc.

<?php

use Phalcon\Mvc\Micro;

$app = new Micro();

$app->get(
    '/invoices/view/{id}',
    function ($id) {
        echo "<h1>Invoice #{$id}!</h1>";
    }
);

$app->handle(
    $_SERVER["REQUEST_URI"]
);

Activation¶

The Phalcon\Mvc\Micro class is the one responsible for creating a Micro application.

<?php

use Phalcon\Di;
use Phalcon\Mvc\Micro;

$container = new Di();
$app       = new Micro($container);

Methods¶

public function __construct(
    DiInterface $container = null
)

Constructor. Accepts an optional Di container.

public function after(
    callable $handler
): Micro

Appends an after middleware to be called after execute the route

public function afterBinding(
    callable $handler
): Micro

Appends a afterBinding middleware to be called after model binding

public function before(
    callable $handler
): Micro

Appends a before middleware to be called before execute the route

public function delete(
    string $routePattern, 
    callable $handler
): RouteInterface

Maps a route to a handler that only matches if the HTTP method is DELETE

public function error(
    callable $handler
): Micro

Sets a handler that will be called when an exception is thrown handling the route

public function finish(
    callable $handler
): Micro

Appends a finish middleware to be called when the request is finished

public function get(
    string $routePattern, 
    callable $handler
): RouteInterface

Maps a route to a handler that only matches if the HTTP method is GET

public function getActiveHandler(): callable

Return the handler that will be called for the matched route

public function getBoundModels(): array

Returns bound models from binder instance

public function getHandlers(): array

Returns the internal handlers attached to the application

public function getModelBinder(): BinderInterface | null

Get the model binder

public function getReturnedValue(): mixed

Returns the value returned by the executed handler

public function getRouter(): RouterInterface

Returns the internal router used by the application

public function getService(
    string $serviceName
): object

Obtains a service from the DI

public function getSharedService(
    string $serviceName
)

Obtains a shared service from the DI

public function handle(
    string $uri
): mixed

Handle the whole request

public function hasService(
    string $serviceName
): bool

Checks if a service is registered in the DI

public function head(
    string $routePattern, 
    callable $handler
): RouteInterface

Maps a route to a handler that only matches if the HTTP method is HEAD

public function map(
    string $routePattern, 
    callable $handler
): RouteInterface

Maps a route to a handler without any HTTP method constraint

public function mount(
    CollectionInterface $collection
): Micro

Mounts a collection of handlers

public function notFound(
    callable $handler
): Micro

Sets a handler that will be called when the router does not match any of the defined routes

public function offsetExists(
    mixed $alias
): bool

Check if a service is registered in the internal DI container using the array syntax

public function offsetGet(
    mixed $alias
): mixed

Gets a DI service from the internal DI container using the array syntax

public function offsetSet(
    mixed $alias, 
    mixed $definition
)

Registers a service in the internal DI container using the array syntax

$app["request"] = new \Phalcon\Http\Request();

public function offsetUnset(
    mixed $alias
): void

Removes a service from the internal DI container using the array syntax

public function options(    
    string $routePattern, 
    callable $handler
): RouteInterface

Maps a route to a handler that only matches if the HTTP method is OPTIONS

public function patch(
    string $routePattern, 
    callable $handler
): RouteInterface

Maps a route to a handler that only matches if the HTTP method is PATCH

public function post(
    string $routePattern, 
    callable $handler
): RouteInterface

Maps a route to a handler that only matches if the HTTP method is POST

public function put(
    string $routePattern, 
    callable $handler
): RouteInterface

Maps a route to a handler that only matches if the HTTP method is PUT

public function setActiveHandler(
    callable $activeHandler
)

Sets externally the handler that must be called by the matched route

public function setModelBinder(
    BinderInterface $modelBinder, 
    mixed $cache = null
): Micro

Sets model binder

$micro = new Micro($di);

$micro->setModelBinder(
    new Binder(),
    'cache'
);

public function setResponseHandler(
    callable $handler
): Micro

Appends a custom response handler to be called instead of the default one

public function setService(
    string $serviceName, 
    mixed $definition, 
    bool $shared = false
): ServiceInterface

Sets a service in the internal Di container. If no container is preset a Phalcon\Di\FactoryDefault will be automatically created

public function stop()

Stops the middleware execution

Routes¶

Defining routes in a Phalcon\Mvc\Micro application is very easy. Routes are defined as follows:

   Application : (http method): (route url/regex, callable PHP function/handler)

Activation¶

Routing is handled by the Phalcon\Mvc\Router object.

NOTE

Routes must always start with /

Usually, the starting route for an application is /, accessed via the GET HTTP method:

<?php

$application->get(
    '/',
    function () {
        echo '<h1>3.1459</h1>';
    }
);

NOTE

Check our routing document for more information for the Phalcon\Mvc\Router

Application object

Routes can be set using the Phalcon\Mvc\Micro application object as follows:

<?php

use Phalcon\Mvc\Micro;

$app = new Micro();

$app->get(
    '/invoices/view/{id}',
    function ($id) {
        echo "<h1>Invoice #{$id}!</h1>";
    }
);

Router object

You can also create a Phalcon\Mvc\Router object, setting the routes there and then injecting it in the dependency injection container.

<?php

use Phalcon\Di;
use Phalcon\Mvc\Micro;
use Phalcon\Mvc\Router;


$router = new Router();
$router->addGet(
    '/invoices/view/{id}',
    'InvoicesClass::view'
);

$container   = new Di();
$application = new Micro($container);

$application->setService('router', $router, true);

Setting up your routes using the Phalcon\Mvc\Micro applications http methods (get, post, etc.) is much easier than setting up a router object with relevant routes and then injecting it in the application. Each method has its advantages and disadvantages. It all depends on the design and needs of your application.

Rewrite Rules¶

In order for routes to work, your web server needs to be configured with specific instructions. Please refer to the webserver setup document for more information.

Handlers¶

Handlers are callable pieces of code that get attached to a route. When the route is matched, the handler is executed with all the defined parameters. A handler is any valid PHP callable.

Registration¶

Phalcon offers several ways to attach a handler to a route. Your application needs and design as well as coding style will be the factors influencing your choice of implementation.

Anonymous Function

You can use an anonymous function to handle the request

<?php

$app->get(
    '/invoices/view/{id}',
    function ($id) {
        echo "<h1>Invoice #{$id}!</h1>";
    }
);

Accessing the $app object inside the anonymous function can be achieved by injecting it as follows:

<?php

$app->get(
    '/invoices/view/{id}',
    function ($id) use ($app){
        $content = "<h1>Invoice #{$id}!</h1>";

        $app->response->setContent($content);

        $app->response->send();
    }
);

Function

You can define a function as the handler and attach it to a specific route.

<?php

function invoiceView($id) {
    echo "<h1>Invoice #{$id}!</h1>";
}

$app->get(
    '/invoices/view/{id}',
    'invoicesView'
);

Static Method

You can also use a static method as the handler.

<?php

class InvoicesClass
{
    public static function view($id) {
        echo "<h1>Invoice #{$id}!</h1>";
    }
}

$app->get(
    '/invoices/view/{id}',
    'InvoicesClass::View'
);

Method in an Object

You can also use a method in an object as the handler.

<?php

class InvoicesClass
{
    public function view($id) {
        echo "<h1>Invoice #{$id}!</h1>";
    }
}

$invoices = new InvoicesClass();
$app->get(
    '/invoices/view/{id}',
    [
        $invoices,
        'view'
    ]
);

Controllers

With the Phalcon\Mvc\Micro you can create micro or medium applications. Medium applications use the micro architecture but expand on it to utilize more than the Micro but less than the Full application. In medium applications you can organize handlers in controllers.

<?php

use Phalcon\Mvc\Micro\Collection as MicroCollection;

$invoices = new MicroCollection();
$invoices
    ->setHandler(new InvoicesController())
    ->setPrefix('/invoices')
    ->get('/', 'index')
    ->get('/view/{id}', 'view')
;

$app->mount($invoices);

The InvoicesController might look like this:

<?php

use Phalcon\Mvc\Controller;

class InvoicesController extends Controller
{
    public function index()
    {
        // ...
    }

    public function view($id) {
        // ...
    }
}

Since our controllers extend the Phalcon\Mvc\Controller, all the dependency injection services are available with their respective registration names.

<?php

use Phalcon\Http\Response;
use Phalcon\Mvc\Controller;

/**
 * @property Response $response
 */
class InvoicesController extends Controller
{
    public function index()
    {
        // ...
    }

    public function view($id)
    {
        $content = "<h1>Invoice #{$id}!</h1>";

        $this->response->setContent($content);

        return $this->response;
    }
}

Lazy Loading¶

In order to increase performance, you might consider implementing lazy loading for your controllers (handlers). The controller will be loaded only if the relevant route is matched.

Lazy loading can be easily achieved when setting your handler in your Phalcon\Mvc\Micro\Collection using the second parameter, or by using the setLazy method.

<?php

use MyApp\Controllers\InvoicesController;

$invoices->setHandler(
    InvoicesController::class, 
    true
);


$invoices
    ->setHandler(InvoicesController::class)
    ->setLazy(true)
    ->setPrefix('/invoices')
    ->get('/', 'index')
    ->get('/view/{id}', 'view')
;

$app->mount($invoices);

Use case

We are developing an API for an online store. The endpoints are /users, /invoices and /products. Each of those endpoints are registered using handlers, and each handler is a controller with relevant actions.

The controllers that we use as handlers are as follows:

<?php

use Phalcon\Mvc\Controller;

class UsersController extends Controller
{
    public function get($id)
    {
        // ...
    }

    public function add($payload)
    {
        // ...
    }
}

class InvoicesController extends Controller
{
    public function get($id)
    {
        // ...
    }

    public function add($payload)
    {
        // ...
    }
}

class ProductsController extends Controller
{
    public function get($id)
    {
        // ...
    }

    public function add($payload)
    {
        // ...
    }
}

We register the handlers:

<?php

use Phalcon\Mvc\Micro\Collection as MicroCollection;

$users = new MicroCollection();
$users
    ->setHandler(new UsersController())
    ->setPrefix('/users')
    ->get(
        '/get/{id}', 
        'get'
    )
    ->get(
        '/add/{payload}', 
        'add'
    )
;

$app->mount($users);

$invoices = new MicroCollection();
$invoices
    ->setHandler(new InvoicesController())
    ->setPrefix('/invoices')
    ->get(
        '/get/{id}', 
        'get'
    )
    ->get(
        '/add/{payload}', 
        'add'
    )
;

$app->mount($invoices);

$products = new MicroCollection();
$products
    ->setHandler(new ProductsController())
    ->setPrefix('/products')
    ->get(
        '/get/{id}', 
        'get'
    )
    ->get(
        '/add/{payload}', 
        'add'
    )
;

$app->mount($products);

This implementation loads each handler in turn and mounts it in our application object. The issue with this approach is that each request will result to only one endpoint and therefore one class method executed. The remaining methods/handlers will just remain in memory without being used.

Using lazy loading we reduce the number of objects loaded in memory and as a result our application uses less memory. The above implementation changes if we want to use lazy loading as follows:

<?php

use Phalcon\Mvc\Micro\Collection as MicroCollection;

$users = new MicroCollection();
$users
    ->setHandler(
        UsersController::class,
        true
    )
    ->setPrefix('/users')
    ->get(
        '/get/{id}', 
        'get'
    )
    ->get(
        '/add/{payload}', 
        'add'
    )
;

$app->mount($users);

$invoices = new MicroCollection();
$invoices
    ->setHandler(
        InvoicesController::class,
        true
    )
    ->setPrefix('/invoices')
    ->get(
        '/get/{id}', 
        'get'
    )
    ->get(
        '/add/{payload}', 
        'add'
    )
;

$app->mount($invoices);

$products = new MicroCollection();
$products
    ->setHandler(
        ProductsController::class,
        true
    )
    ->setPrefix('/products')
    ->get(
        '/get/{id}', 
        'get'
    )
    ->get(
        '/add/{payload}', 
        'add'
    )

$app->mount($products);

Using this simple change in implementation, all handlers remain non instantiated until requested by a caller. Therefore whenever a caller requests /invoices/get/2, our application will instantiate the InvoicesController and call the get method in it. Our application now uses less resources than before.

Extra performance tip¶

If you are working on a large application, there is no need to mount all the collections, even if they are lazy loaded: Phalcon will use regex to match the routes. To speed up the routing process it is possible to run a pre-filter like this, using the previous example:

In this way, Phalcon can handle tens (or hundreds) name=__codelineno-55-1 href=#__codelineno-55-1> $uri = new \Phalcon\Http\Message\Uri($_SERVER['REQUEST_URI']); $path = $uri->getPath(); $parts = explode("/", $path); $collection = $parts[1]; switch ($collection) { case "users": $users = new MicroCollection(); $users ->setHandler( UsersController::class, true ) ->setPrefix('/users') ->get( '/get/{id}', 'get' ) ->get( '/add/{payload}', 'add' ) ; $app->mount($users); break; case "invoices": $invoices = new MicroCollection(); $invoices ->setHandler( InvoicesController::class, true ) ->setPrefix('/invoices') ->get( '/get/{id}', 'get' ) ->get( '/add/{payload}', 'add' ) ; $app->mount($invoices); break; case "products": $products = new MicroCollection(); $products ->setHandler( ProductsController::class, true ) ->setPrefix('/products') ->get( '/get/{id}', 'get' ) ->get( '/add/{payload}', 'add' ) $app->mount($products); break; default: //do nothing (or something) } of routes without regex performance penalty: using explode() is faster than regex.

Not found (404)¶

Any route that has not been matched in our Phalcon\Mvc\Micro application will cause it to try and execute the handler defined with the notFound method. Similar to other http methods (get, post etc.), you can register a handler in the notFound method which can be any callable PHP function.

<?php

$app->notFound(
    function () use ($app) {
        $message = 'Nothing to see here. Move along....';
        $app
            ->response
            ->setStatusCode(404, 'Not Found')
            ->sendHeaders()
            ->setContent($message)
            ->send()
        ;
    }
);

You can also handle routes that have not been matched (404) with Middleware discussed below.

HTTP methods¶

The Phalcon\Mvc\Micro application provides a set of methods to bind the HTTP method with the route it is intended to.

delete

Matches if the HTTP method is DELETE and the route is /api/products/delete/{id}

<?php

$app->delete(
    '/api/products/delete/{id}',
    'deleteProduct'
);

get

Matches if the HTTP method is GET and the route is /api/products

<?php

$app->get(
    '/api/products',
    'getProducts'
);

head

Matches if the HTTP method is HEAD and the route is /api/products

<?php

$app->head(
    '/api/products',
    'getProducts'
);

map

Map allows you to attach the same endpoint to more than one HTTP method. The example below matches if the HTTP method is GET or POST and the route is /repos/store/refs

<?php

$app
    ->map(
        '/repos/store/refs',
        'actionProduct'
    )
    ->via(
        [
            'GET',
            'POST',
        ]
    );

options

Matches if the HTTP method is OPTIONS and the route is /api/products/options

<?php

$app->options(
    '/api/products/options',
    'infoProduct'
);

patch

Matches if the HTTP method is PATCH and the route is /api/products/update/{id}

<?php

$app->patch(
    '/api/products/update/{id}',
    'updateProduct'
);

post

Matches if the HTTP method is POST and the route is /api/products/add

<?php

$app->post(
    '/api/products',
    'addProduct'
);

put

Matches if the HTTP method is PUT and the route is /api/products/update/{id}

<?php

$app->put(
    '/api/products/update/{id}',
    'updateProduct'
);

Collections¶

Collections are a handy way to group collections attached to a handler and a common prefix (if needed). For a hypothetical /invoices endpoint we could have the following routes:

/invoices/get/{id}
/invoices/add/{payload}
/invoices/update/{id}
/invoices/delete/{id}

All of those routes are handled by our InvoicesController. We set up our routes with a collection as follows:

<?php

use Phalcon\Mvc\Micro\Collection as MicroCollection;

$invoices = new MicroCollection();
$invoices->setHandler(new InvoicesController());

$invoices->setPrefix('/invoices');

$invoices->get('/get/{id}', 'displayAction');
$invoices->get('/add/{payload}', 'addAction');
$invoices->get('/update/{id}', 'updateAction');
$invoices->get('/delete/{id}', 'deleteAction');

$app->mount($invoices);

NOTE

The name that we bind each route has a suffix of Action. This is not necessary, your method can be called anything you like.

Methods

The available methods for the Phalcon\Mvc\Micro\Collection object are:

public function delete(
    string $routePattern, 
    callable $handler, 
    string $name = null
): CollectionInterface

Maps a route to a handler that only matches if the HTTP method is DELETE.

public function get(
    string $routePattern, 
    callable $handler,  
    string $name = null
): CollectionInterface

Maps a route to a handler that only matches if the HTTP method is GET.

public function getHandler(): mixed

Returns the main handler

public function getHandlers(): array

Returns the registered handlers

public function getPrefix(): string

Returns the collection prefix if any

public function head(
    string $routePattern, 
    callable $handler, 
    string $name = null
): CollectionInterface

Maps a route to a handler that only matches if the HTTP method is HEAD.

public function isLazy(): bool

Returns if the main handler must be lazy loaded

public function map(
    string $routePattern, 
    callable $handler, 
    string | array $method, 
    string $name = null
): CollectionInterface

Maps a route to a handler.

public function mapVia(
    string $routePattern, 
    callable $handler, 
    string | array $method, 
    string $name = null
): CollectionInterface

Maps a route to a handler via methods.

$collection->mapVia(
    "/invoices",
    "indexAction",
    [
        "POST", 
        "GET"
    ],
    "invoices"
);

public function options(
    string $routePattern, 
    callable $handler, 
    string $name = null
): CollectionInterface

Maps a route to a handler that only matches if the HTTP method is OPTIONS.

public function patch(
    string $routePattern, 
    callable $handler, 
    string $name = null
): CollectionInterface

Maps a route to a handler that only matches if the HTTP method is PATCH.

public function post(
    string $routePattern, 
    callable $handler, 
    string $name = null
): CollectionInterface

Maps a route to a handler that only matches if the HTTP method is POST.

public function put(
    string $routePattern, 
    callable $handler, 
    string $name = null
): CollectionInterface

Maps a route to a handler that only matches if the HTTP method is PUT.

public function setHandler(
    callable $handler, 
    bool $lazy = false
): CollectionInterface

Sets the main handler.

public function setLazy(
    bool $lazy
): CollectionInterface

Sets if the main handler must be lazy loaded

public function setPrefix(
    string $prefix
): CollectionInterface

Sets a prefix for all routes added to the collection

Parameters¶

We have briefly seen above how parameters are defined in the routes. Parameters are set in a route string by enclosing the name of the parameter in brackets.

<?php

$app->get(
    '/invoices/view/{id}',
    function ($id) {
        echo "<h1>Invoice #{$id}!</h1>";
    }
);

We can also enforce certain rules for each parameter by using regular expressions. The regular expression is set after the name of the parameter, separating it with :.

<?php

$app->get(
    '/invoices/view/{id:[0-9]+}',
    function ($id) {
        echo "<h1>Invoice #{$id}!</h1>";
    }
);

$app->get(
    '/invoices/search/year/{year:[0-9][4]}/title/{title:[a-zA-Z\-]+}',
    function ($year, $title) {
        echo "'<h1>Title: {$title}</h1>", PHP_EOL,
             "'<h2>Year: {$year}</h2>"
        ;
    }
);

NOTE

Check our routing document for more information for the Phalcon\Mvc\Router

Redirections¶

You can redirect one matched route to another using the Phalcon\Http\Response object, just like in a full application.

<?php

$app->get('/invoices/show/{id}',
    function ($id) use ($app) {
        $app
            ->response
            ->redirect(
                "invoices/view/{$id}"
            )
            ->sendHeaders()
        ;
    }
);

$app->get('/invoices/view/{id}',
    function ($id) use ($app) {
        echo "<h1>Invoice #{$id}!</h1>";
    }
);

NOTE

We have to pass the $app object in our anonymous function to have access to the request object.

When using controllers as handlers, you can perform the redirect just as easy:

<?php

use Phalcon\Http\Response;
use Phalcon\Mvc\Controller;

/**
 * @property Response $response
 */
class InvoicesController extends Controller
{
    public function show($id)
    {
        return $this
            ->response
            ->redirect(
                "invoices/view/{$id}"
            )
        ;
    }

    public function get($id)
    {
        // ...
    }
}

Finally, you can perform redirections in your middleware (if you are using it). An example is below in the relevant section.

URLs¶

Another feature of the routes is setting up named routes and generating URLs for those routes.

You will need to name your routes to take advantage of this feature. This can be achieved with the setName() method that is exposed from the http methods in our application (get, post, etc.);

<?php

$app
    ->get(
        '/invoices/view/{id}',
        function ($id) use ($app) {
            // ...
        }
    )
    ->setName('view-invoice');

If you are using the Phalcon\Mvc\Micro\Collection object, the name needs to be the third parameter of the methods setting the routes.

<?php

$invoices = new MicroCollection();

$invoices
    ->setHandler(
        InvoicesController::class,
        true
    )
    ->setPrefix('/invoices')
    ->get(
        '/view/{id}', 
        'get', 
        'view-invoice'
    )
    ->post(
        '/add', 
        'post', 
        'add-invoice'
    )
;

$app->mount($invoices);

Lastly you need the Phalcon\Url component to generate URLs for the named routes.

<?php

$app->get(
    '/',
    function () use ($app) {
        $url = sprintf(
            '<a href="%s">Invoice</a>',
            $app
                ->url
                ->get(
                    [
                        'for' => 'view-invoice',
                        'id'  => 1234,
                    ]
                )
        );

        echo $url;
    }
);

Dependency Injector¶

When a micro application is created, a Phalcon\Di\FactoryDefault services container is created automatically.

<?php

use Phalcon\Mvc\Micro;

$app = new Micro();

$app->get(
    '/',
    function () use ($app) {
        $app
            ->response
            ->setContent('3.1459')
            ->send()
        ;
    }
);

You can also create a DI container yourself, and assign it to the micro application, therefore manipulating the services depending on the needs of your application.

<?php

use Phalcon\Di;
use Phalcon\Mvc\Micro;
use Phalcon\Config\Adapter\Ini;

$container = new Di();

$container->set(
    'config',
    function () {
        return new Ini(
            'config.ini'
        );
    }
);

$app = new Micro($container);

$app->get(
    '/',
    function () use ($app) {
        echo $app
            ->config
            ->app_name;
    }
);

$app->post(
    '/contact',
    function () use ($app) {
        $app
            ->flash
            ->success('What are you doing Dave?')
        ;
    }
);

You can also use the array syntax to register services in the dependency injection container from the application object:

<?php

use Phalcon\Mvc\Micro;
use Phalcon\Db\Adapter\Pdo\Mysql;

$app = new Micro();

$app['db'] = function () {
    return new Mysql(
        [
            'host'     => 'localhost',
            'username' => 'root',
            'password' => 'secret',
            'dbname'   => 'test_db',
        ]
    );
};

$app->get(
    '/blog',
    function () use ($app) {
        $invoices = $app['db']->query(
            'SELECT * FROM co_invoices'
        );

        foreach ($invoices as $invoice) {
            echo $invoice->inv_title;
        }
    }
);

Responses¶

A micro application can return many different types of responses. Direct output, use a template engine, calculated data, view based data, JSON etc.

Handlers may return raw responses using plain text, Phalcon\Http\Response object or a custom built component that implements the Phalcon\Http\ResponseInterface.

Direct¶

<?php

$app->get(
    '/invoices/view/{id}',
    function ($id) {
        echo "<h1>Invoice #{$id}!</h1>";
    }
);

Including Files¶

<?php

$app->get(
    '/invoices/view/{id}',
    function ($id) {
        require 'views/results.php';
    }
);

Direct - JSON¶

<?php

$app->get(
    '/invoices/view/{id}',
    function ($id) {
        echo json_encode(
            [
                'code' => 200,
                'id'   => $id,
            ]
        );
    }
);

New Response¶

You can use the setContent method of a new Phalcon\Http\Response object to return the response back.

<?php

use Phalcon\Http\Response;

$app->get(
    '/invoices/list',
    function () {
        return (new Response())
            ->setContentType('text/plain')
            ->setContent(
                file_get_contents('data.txt')
            )
        ;
    }
);

Application Response¶

You can also use the Phalcon\Http\Response from the application to return responses to the caller.

<?php

$app->get(
    '/invoices/list',
    function () use ($app) {
        $app
            ->response
            ->setContentType('text/plain')
            ->sendHeaders()
        ;

        readfile('data.txt');
    }
);

Return Response¶

A different approach returning data back to the caller is to return the Phalcon\Http\Response object directly from the application. When responses are returned by handlers they are automatically sent by the application.

<?php

use Phalcon\Mvc\Micro;
use Phalcon\Http\Response;

$app = new Micro();

$app->get(
    '/invoices//list',
    function () {
        return (new Response())
            ->setStatusCode(
                401, 
                'Unauthorized'
            )
            ->setContent(
                '401 - Unauthorized'
            )
        ;
    }
);

JSON¶

JSON can be sent back just as easy using the Phalcon\Http\Response object.

<?php

$app->get(
    '/invoices/index',
    function () use ($app) {

        $data = [
            'code'    => 401,
            'status'  => 'error',
            'message' => 'Unauthorized access',
            'payload' => [],
        ];

        return $this
            ->response
            ->setJsonContent($data)
        ;
    }
);

Events¶

A Phalcon\Mvc\Micro application works closely with an Events Manager if it is present, to trigger events that can be used throughout our application. The type of those events is micro. These events trigger in our application and can be attached to relevant handlers that will perform actions needed by our application.

Available events¶

The following events are supported:

Event Name	Triggered	Can stop
`afterBinding`	Triggered after models are bound but before executing the handler	Yes
`afterExecuteRoute`	Handler just finished running	No
`afterHandleRoute`	Route just finished executing	Yes
`beforeExecuteRoute`	Route matched, Handler valid, Handler has not been executed yet	Yes
`beforeHandleRoute`	Main method called; Routes have not been checked yet	Yes
`beforeNotFound`	Route has not been found	Yes

Authentication example¶

You can easily check whether a user has been authenticated or not using the beforeExecuteRoute event. The following example demonstrates such a scenario:

<?php

use Phalcon\Mvc\Micro;
use Phalcon\Events\Event;
use Phalcon\Events\Manager;

$manager = new Manager();

$manager->attach(
    'micro:beforeExecuteRoute',
    function (Event $event, $app) {
        if ($app->session->get('auth') === false) {
            $app->flashSession->error(
                "The user is not authenticated"
            );

            $app->response->redirect('/');
            $app->response->sendHeaders();

            return false;
        }
    }
);

$app = new Micro();

$app->setEventsManager($manager);

Not found example¶

You can also create a redirect for a route that does not exist (404). To do so you can use the beforeNotFound event. The following example demonstrates such a scenario:

<?php

use Phalcon\Mvc\Micro;
use Phalcon\Events\Event;
use Phalcon\Events\Manager;

$manager = new Manager();

$manager->attach(
    'micro:beforeNotFound',
    function (Event $event, $app) {
        $app->response->redirect('/404');
        $app->response->sendHeaders();

        return $app->response;
    }
);

$app = new Micro();

$app->setEventsManager($manager);

Middleware¶

Middleware are classes that can be attached to your application and introduce another layer where business logic can exist. They run sequentially, according to the order they are registered and not only improve maintainability, by encapsulating specific functionality, but also performance. A middleware class can stop execution when a particular business rule has not been satisfied, thus allowing the application to exit early without executing the full cycle of a request.

NOTE

The middleware handled by the Micro application are not compatible with PSR-15. In future versions of Phalcon, the whole HTTP layer will be rewritten to align with PSR-7 and PSR-15.

The presence of a Phalcon\Events\Manager is essential for middleware to operate, so it has to be registered in our DI container.

Attached events¶

Middleware can be attached to a micro application in 3 different events. Those are:

Event	Description
`before`	Before the handler has been executed
`after`	After the handler has been executed
`finish`	After the response has been sent to the caller

NOTE

You can attach as many middleware classes as you want in each of the above events. They will be executed sequentially when the relevant event fires.

before

This event is perfect for stopping execution of the application if certain criteria is not met. In the below example we are checking if the user has been authenticated and stop execution with the necessary redirect.

<?php

$app->before(
    function () use ($app) {
        if (false === $app['session']->get('auth')) {
            $app
                ->flashSession
                ->error("The user is not authenticated")
            ;

            $app
                ->response
                ->redirect('/error')
            ;

            return false;
        }

        return true;
    }
);

The code above executes before every route is executed. Returning false cancels the route execution.

after

This event can be used to manipulate data or perform actions that are needed after the handler has finished executing.

<?php

$app->map(
    '/invoices/list',
    function () {
        return [
            1234 => [
                'total'      => 100,
                'customerId' => 3,
                'title'      => 'Invoice for ACME Inc.',
            ]
        ];
    }
);

$app->after(
    function () use ($app) {
        echo json_encode(
            $app->getReturnedValue()
        );
    }
);

In the above example, the handler returns an array of data. The after event calls json_encode on it, thus returning valid JSON.

NOTE

You will need to do a bit more work here to set the necessary headers for JSON. An alternative to the above code would be to use the Response object and setJsonContent

finish

This even will fire up when the whole request cycle has been completed.

<?php

$app->finish(
    function () use ($app) {
        if (true === file_exists('/tmp/processing.cache')) {
            unlink('/tmp/processing.cache');
        }
    }
);

In the above example we utilize the finish event to do some cache cleaning.

Activation¶

Attaching middleware to your application is very easy as shown above, with the before, after and finish method calls.

<?php

$app->before(
    function () use ($app) {
        if (false === $app['session']->get('auth')) {
            $app['flashSession']
                ->error("The user isn not authenticated")
            ;

            $app['response']
                ->redirect('/error')
            ;

            return false;
        }

        return true;
    }
);

$app->after(
    function () use ($app) {
        echo json_encode(
            $app->getReturnedValue()
        );
    }
);

You can also use classes and attach them to the Events Manager as listener. Using this approach offers more flexibility and reduces the bootstrap file size, since the middleware logic is encapsulated in one file per middleware.

<?php

use Phalcon\Events\Manager;
use Phalcon\Mvc\Micro;

use Website\Middleware\CacheMiddleware;
use Website\Middleware\NotFoundMiddleware;
use Website\Middleware\ResponseMiddleware;

/**
 * Create a new Events Manager.
 */
$manager     = new Manager();
$application = new Micro();

// before
$manager->attach(
    'micro',
    new CacheMiddleware()
);

$application->before(
    new CacheMiddleware()
);

$manager->attach(
    'micro',
    new NotFoundMiddleware()
);

$application->before(
    new NotFoundMiddleware()
);

// after
$manager->attach(
    'micro',
    new ResponseMiddleware()
);

$application->after(
    new ResponseMiddleware()
);

$application->setEventsManager($manager);

We need a Phalcon\Events\Manager object. This can be a newly instantiated object or we can get the one that exists in our DI container (if you have used the FactoryDefault one, or if you have not set up a DI container, since it will be automatically created for you).

We attach every middleware class in the micro hook in the Events Manager. We could also be a bit more specific and attach it to say the micro:beforeExecuteRoute event.

We then attach the middleware class in our application on one of the three listening events discussed above (before, after, finish).

Implementation¶

Middleware can be any kind of PHP callable functions. You can organize your code whichever way you like it to implement middleware. If you choose to use classes for your middleware, you will need them to implement the Phalcon\Mvc\Micro\MiddlewareInterface

<?php

use Phalcon\Mvc\Micro;
use Phalcon\Mvc\Micro\MiddlewareInterface;

/**
 * CacheMiddleware
 */
class CacheMiddleware implements MiddlewareInterface
{
    /**
     * Calls the middleware
     *
     * @param Micro $application
     *
     * @returns bool
     */
    public function call(Micro $application)
    {
        $cache  = $application['cache'];
        $router = $application['router'];

        $key = preg_replace(
            '/^[a-zA-Z0-9]/',
            '',
            $router->getRewriteUri()
        );

        // Check if the request is cached
        if ($cache->exists($key)) {
            echo $cache->get($key);

            return false;
        }

        return true;
    }
}

Middleware Events¶

The events that are triggered for our application also trigger inside a class that implements the Phalcon\Mvc\Micro\MiddlewareInterface. This offers great flexibility and power for developers since we can interact with the request process.

API example

Assume that we have an API that we have implemented with the Micro application. We will need to attach different Middleware classes in the application so that we can better control the execution of the application.

The middleware that we will use are:

Firewall
NotFound
Redirect
CORS
Request
Response

Firewall Middleware

This middleware is attached to the before event of our Micro application. The purpose of this middleware is to check who is calling our API and based on a whitelist, allow them to proceed or not

<?php

use Phalcon\Events\Event;
use Phalcon\Http\Request;
use Phalcon\Http\Response;
use Phalcon\Mvc\Micro;
use Phalcon\Mvc\Micro\MiddlewareInterface;

/**
 * FirewallMiddleware
 *
 * @property Request  $request
 * @property Response $response
 */
class FirewallMiddleware implements MiddlewareInterface
{
    /**
     * @param Event $event
     * @param Micro $application
     *
     * @returns bool
     */
    public function beforeHandleRoute(
        Event $event, 
        Micro $application
    ) {
        $whitelist = [
            '10.4.6.1',
            '10.4.6.2',
            '10.4.6.3',
            '10.4.6.4',
        ];

        $ipAddress = $application
            ->request
            ->getClientAddress()
        ;

        if (true !== array_key_exists($ipAddress, $whitelist)) {
            $this
                ->response
                ->redirect('/401')
                ->send()
            ;

            return false;
        }

        return true;
    }

    /**
     * @param Micro $application
     *
     * @returns bool
     */
    public function call(Micro $application)
    {
        return true;
    }
}

Not Found (404) Middleware

When this middleware is processed, this means that the requesting IP is allowed to access our application. The application will try to match the route and if not found the beforeNotFound event will fire. We will stop the processing then and send back to the user the relevant 404 response. This middleware is attached to the before event of our Micro application

<?php

use Phalcon\Http\Response;
use Phalcon\Mvc\Micro;
use Phalcon\Mvc\Micro\MiddlewareInterface;

/**
 * NotFoundMiddleware
 *
 * @property Response $response
 */
class NotFoundMiddleware implements MiddlewareInterface
{
    /**
     * @param Event $event
     * @param Micro $application
     *
     * @returns bool
     */
    public function beforeNotFound(Event $event, Micro $application)
    {
        $application->response->redirect('/404');
        $application->response->send();

        return false;
    }

    /**
     * @param Micro $application
     *
     * @returns bool
     */
    public function call(Micro $application)
    {
        return true;
    }
}

Redirect Middleware

We attach this middleware again to the before event of our Micro application because we do not want the request to proceed if the requested endpoint needs to be redirected.

<?php

use Phalcon\Http\Request;
use Phalcon\Http\Response;
use Phalcon\Events\Event;
use Phalcon\Mvc\Micro;
use Phalcon\Mvc\Micro\MiddlewareInterface;

/**
 * RedirectMiddleware
 *
 * @property Request  $request
 * @property Response $response
 */
class RedirectMiddleware implements MiddlewareInterface
{
    /**
     * Before anything happens
     *
     * @param Event $event
     * @param Micro $application
     *
     * @returns bool
     */
    public function beforeHandleRoute(
        Event $event, 
        Micro $application
    ) {
        if ('github' === $application->request->getURI()) {
            $application
                ->response
                ->redirect('https://github.com')
                ->send()
            ;

            return false;
        }

        return true;
    }

    /**
     * @param Micro $application
     *
     * @returns bool
     */
    public function call(Micro $application)
    {
        return true;
    }
}

CORS Middleware¶

Again this middleware is attached to the before event of our Micro application. We need to ensure that it fires before anything happens with our application

<?php

use Phalcon\Events\Event;
use Phalcon\Http\Request;
use Phalcon\Http\Response;
use Phalcon\Mvc\Micro;
use Phalcon\Mvc\Micro\MiddlewareInterface;

/**
 * CORSMiddleware
 *
 * @property Request  $request
 * @property Response $response
 */
class CORSMiddleware implements MiddlewareInterface
{
    /**
     * @param Event $event
     * @param Micro $application
     *
     * @returns bool
     */
    public function beforeHandleRoute(
        Event $event, 
        Micro $application
    ) {
        if ($application->request->getHeader('ORIGIN')) {
            $origin = $application
                ->request
                ->getHeader('ORIGIN')
            ;
        } else {
            $origin = '*';
        }

        $application
            ->response
            ->setHeader(
                'Access-Control-Allow-Origin', 
                $origin
            )
            ->setHeader(
                'Access-Control-Allow-Methods',
                'GET,PUT,POST,DELETE,OPTIONS'
            )
            ->setHeader(
                'Access-Control-Allow-Headers',
                'Origin, X-Requested-With, Content-Range, ' .
                'Content-Disposition, Content-Type, Authorization'
            )
            ->setHeader(
                'Access-Control-Allow-Credentials', 
                'true'
            )
        ;
    }

    /**
     * @param Micro $application
     *
     * @returns bool
     */
    public function call(Micro $application)
    {
        return true;
    }
}

Request Middleware

This middleware is receiving a JSON payload and checks it. If the JSON payload is not valid it will stop execution.

<?php

use Phalcon\Events\Event;
use Phalcon\Http\Request;
use Phalcon\Http\Response;
use Phalcon\Mvc\Micro;
use Phalcon\Mvc\Micro\MiddlewareInterface;

/**
 * RequestMiddleware
 *
 * @property Request  $request
 * @property Response $response
 */
class RequestMiddleware implements MiddlewareInterface
{
    /**
     * @param Event $event
     * @param Micro $application
     *
     * @returns bool
     */
    public function beforeExecuteRoute(
        Event $event, 
        Micro $application
    ) {
        json_decode(
            $application
                ->request
                ->getRawBody()
        );

        if (JSON_ERROR_NONE !== json_last_error()) {
            $application
                ->response
                ->redirect('/malformed')
                ->send()
            ;

            return false;
        }

        return true;

    }

    /**
     * @param Micro $application
     *
     * @returns bool
     */
    public function call(Micro $application)
    {
        return true;
    }
}

Response Middleware

This middleware is responsible for manipulating our response and sending it back to the caller as a JSON string. Therefore we need to attach it to the after event of our Micro application.

NOTE

We are going to be using the call method for this middleware, since we have nearly executed the whole request cycle.

<?php

use Phalcon\Http\Response;
use Phalcon\Mvc\Micro;
use Phalcon\Mvc\Micro\MiddlewareInterface;

/**
 * ResponseMiddleware
 *
 * @property Response $response
 */
class ResponseMiddleware implements MiddlewareInterface
{
     /**
      * @param Micro $application
      *
      * @returns bool
      */
    public function call(Micro $application)
    {
        $payload = [
            'code'    => 200,
            'status'  => 'success',
            'message' => '',
            'payload' => $application->getReturnedValue(),
        ];

        $application
            ->response
            ->setJsonContent($payload)
            ->send()
        ;

        return true;
    }
}

Models¶

Models can be used in Micro applications, so long as we instruct the application how it can find the relevant classes with an autoloader.

NOTE

The relevant db service must be registered in your DI container.

<?php

use MyApp\Models\Invoices;
use Phalcon\Loader;
use Phalcon\Mvc\Micro;

$loader = new Loader();
$loader
    ->registerDirs(
        [
            __DIR__ . '/models/',
        ]
    )
    ->register();

$app = new Micro();

$app->get(
    '/invoices/find',
    function () {
        $invoices = Invoices::find();

        foreach ($invoices as $invoice) {
            echo $invoice->inv_id, '<br>';
        }
    }
);

$app->handle(
    $_SERVER["REQUEST_URI"]
);

Model injection¶

By using the Phalcon\Mvc\Model\Binder class you can inject model instances into your routes:

<?php

use MyApp\Models\Invoices;
use Phalcon\Loader;
use Phalcon\Mvc\Micro;
use Phalcon\Mvc\Model\Binder;

$loader = new Loader();

$loader->registerDirs(
    [
        __DIR__ . '/models/',
    ]
)->register();

$app = new Micro();

$app->setModelBinder(
    new Binder()
);

$app->get(
    "/invoices/view/{id:[0-9]+}",
    function (Invoices $id) {
        // ...
    }
);

$app->handle(
    $_SERVER["REQUEST_URI"]
);

Since the Binder object is using internally PHP's Reflection API which requires additional CPU cycles, there is an option to set a cache so as to speed up the process. This can be done by using the second argument of setModelBinder() which can also accept a service name or just by passing a cache instance to the Binder constructor.

Currently the binder will only use the models primary key to perform a findFirst() on. An example route for the above would be /invoices/view/1.

Views¶

Phalcon\Mvc\Micro does not have inherently a view service. We can however use the Phalcon\Mvc\View\Simple component to render views.

<?php

use Phalcon\Mvc\Micro;
use Phalcon\Mvc\View\Simple;

$app = new Micro();

$app['view'] = function () {
    $view = new Simple();
    $view->setViewsDir('app/views/');

    return $view;
};

$app->get(
    '/invoices/show',
    function () use ($app) {
        // app/views/invoices/view.phtml
        echo $app['view']
            ->render(
                'invoices/view',
                [
                    'id'         => 4,
                    'customerId' => 3,
                    'title'      => 'Invoice for ACME Inc.',
                    'total'      => 100,
                ]
            )
        ;
    }
);

NOTE

The above example uses the Phalcon\Mvc\View\Simple component, which uses relative paths instead of controllers and actions. You can use the Phalcon\Mvc\View component instead, but to do so you will need to change the parameters passed to render().

<?php

use Phalcon\Mvc\Micro;
use Phalcon\Mvc\View;

$app['view'] = function () {
    $view = new View();

    $view->setViewsDir('app/views/');

    return $view;
};

$app->get(
    '/invoices/view',
    function () use ($app) {
        // app/views/invoices/view.phtml
        echo $app['view']
            ->render(
                'invoices',
                'view',
                [
                    'id'         => 4,
                    'customerId' => 3,
                    'title'      => 'Invoice for ACME Inc.',
                    'total'      => 100,
                ]
            )
        ;
    }
);

Exceptions¶

Any exceptions thrown in the Phalcon\Mvc\Micro component will be of type Phalcon\Mvc\Micro\Exception. You can use this exception to selectively catch exceptions thrown only from this component.

<?php

use Phalcon\Mvc\Micro;
use Phalcon\Mvc\Micro\Exception;

try {
    $app = new Micro();
    $app->before(false);

    $app->handle(
        $_SERVER["REQUEST_URI"]
    );
} catch (Exception $ex) {
    echo $ex->getMessage();
}

Error Handling¶

The Phalcon\Mvc\Micro application also has an error method, which can be used to trap any errors that originate from exceptions. The following code snippet shows basic usage of this feature:

<?php

use Phalcon\Mvc\Micro;

$app = new Micro();

$app->get(
    '/',
    function () {
        throw new \Exception(
            'Error', 
            401
        );
    }
);

$app->error(
    function ($exception) {
        echo json_encode(
            [
                'code'    => $exception->getCode(),
                'status'  => 'error',
                'message' => $exception->getMessage(),
            ]
        );
    }
);