Request

HTTP request has a method, URI, a set of headers and a body:

POST /contact HTTP/1.1
Host: example.org
Accept-Language: en-us
Accept-Encoding: gzip, deflate

{
    "subject": "Hello",
    "body": "Hello there, we need to build Yii application together!"
}

The method is POST, URI is /contact. Extra headers are specifying host, preferred language and encoding. The body could be anything. In this case, it’s JSON payload.

Yii uses PSR-7 ServerRequest as request representation. The object is available in controller actions and other types of middleware:

public function view(ServerRequestInterface $request): ResponseInterface
{
    // ...
}

Method

The method could be obtained from request object:

$method = $request->getMethod();

Usually it’s one of the:

• GET
• POST
• PUT
• DELETE
• HEAD
• PATCH
• OPTIONS

In case you want to make sure the request method is of a certain type, there is a special class with method names:

use Yiisoft\Http\Method;

if ($request->getMethod() === Method::POST) {
    // method is POST
}

URI

A URI has:

• Scheme (http, https)
• Host (yiiframework.com)
• Port (80, 443)
• Path (/posts/1)
• Query string (page=1&sort=+id)
• Fragment (#anchor)

You can obtain UriInterface from request like the following:

$uri = $request->getUri();

Then you can get various details from its methods:

• getScheme()
• getAuthority()
• getUserInfo()
• getHost()
• getPort()
• getPath()
• getQuery()
• getFragment()

Headers

There are various methods to inspect request headers. To get all headers as an array:

$headers = $request->getHeaders();
foreach ($headers as $name => $values) {
   // ...
}

To obtain a single header:

$values = $request->getHeader('Accept-Encoding');

Also, you could obtain value as a comma-separated string instead of an array. That’s especially handy if a header has a single value:

if ($request->getHeaderLine('X-Requested-With') === 'XMLHttpRequest') {
    // This is AJAX request made with jQuery.
    // Note that header presence and name may vary depending on the library used. 
}

To check if a header is present in the request:

if ($request->hasHeader('Accept-Encoding')) {
    // ...
}

Body

There are two methods to obtain body contents. First is getting body as is without parsing:

$body = $request->getBody();

The $body would be an instance of Psr\Http\Message\StreamInterface.

Also, you could obtain a parsed body:

$bodyParameters = $request->getParsedBody();

Parsing depends on PSR-7 implementation and may require middleware for custom body formats.

<?php
use Psr\Http\Message\ServerRequestInterface as Request;
use Psr\Http\Message\ResponseInterface as Response;
use Psr\Http\Server\MiddlewareInterface;
use Psr\Http\Server\RequestHandlerInterface as RequestHandler;

class JsonBodyParserMiddleware implements MiddlewareInterface
{
    public function process(Request $request, RequestHandler $next): Response
    {
        $contentType = $request->getHeaderLine('Content-Type');

        if (strpos($contentType, 'application/json') !== false) {
            $body = $request->getBody();
            $parsedBody = $this->parse($body);
            $request = $request->withParsedBody($parsedBody);
            
        }

        return $next->handle($request);
    }
}

File uploads

Uploaded files that user submitted from a form with enctype attribute equals to multipart/form-data are handled via special request method:

$files = $request->getUploadedFiles();
foreach ($files as $file) {
    if ($file->getError() === UPLOAD_ERR_OK) {
        $file->moveTo('path/to/uploads/new_filename.ext');
    }
}

Attributes

Application middleware may set custom request attributes using withAttribute() method. You can obtain these attributes with getAttribute().