A small and modern PSR-7 & PSR-18 implementation

dev-trunk 2021-07-23 00:08 UTC

This package is auto-updated.

Last update: 2024-04-23 06:18:42 UTC


README

A small, modern, PSR-7 compatible PSR-17 and PSR-18 network library for PHP, inspired by Go's net package.

Features:

  • No hard dependencies;
  • Favours a BYOB approach to requests & responses;
  • Zero configuration – pure data and interfaces;
  • Testing with third-party APIs made easy;

Setup

Some basic instructions on how to use this in your own project, or contribute to it as a develper.

Requirements

  • PHP >=8.0;
  • Any PSR-7 HTTP message implementation;

Installation

Use composer and access it via your autoloader.

composer require minibase-app/net

For Contributors:

Clone the repository and install the development tools to begin running tests for your features & bug fixes.

git clone https://github.com/minibase-app/net.git \
  && cd ./net \
  && make vendor;

Usage

Here is a snippet which details the most basic setup and usage of the library.

As mentioned earlier in the Requirements and Features, you can use any PSR-7 implementation of your choosing. In all examples from here on out we use Laminas for demonstration, but anything is fine, either hand-rolled or from another library.

use Laminas\Diactoros\{ Request, Response, Uri };
use Minibase\Net\Http;
use Psr\Http\Message\{ RequestInterface, ResponseInterface, UriInterface };

# Initiate a new HTTP instance with PSR-17 requesst & response factory closures
$http = new Http(
    fn (string $method, UriInterface $uri): RequestInterface =>
        new Request($uri, $method),
    fn (mixed $body, int $code, string $reason): ResponseInterface =>
        new Response($body, $code),
);

# Store and fetch a URI instance of your API base URL
$api = new Uri('http://localhost/api');

# Make a request to (any) API and specify resources, queries, etc.
$response = $http->get($api->withPath('users')->withQuery('?_limit=1'));

# Introspect your response
$successful = Http::OK === $response->getStatusCode();

If this isn't a good enough explanation of how this works, don't worry – we will cover each piece in detail next.

Creating a New HTTP Instance

Because this library does not provide (yet another) PSR-7 implemenation, you MUST supply one yourself. This means you can make one, use your company's implementation, or pick your favourite package from the community – in any case it doesn't matter, we only care about the interface.

Once you have a PSR-7 implementation it is time to tell the Http class how it should create requests and responses. This is probably the best part of the library; unlike traditional PHP HTTP "client" libraries, this one does not try to abstract the request/response away into array-based configuration, but instead uses them as a configuration. In other words, your request is it's command, literally...

Let's take a look.

# Here we will make a simple JSON REST API implementation
# Notice that $request and $response are merely PSR-17 factories!
$request = fn (string $method, UriInterface $uri): RequestInterface =>
    new Request($method, $uri, headers: ['content-type' => 'application/json']);
$response = fn (array $body, int $code, string $reason): ResponseInterface =>
    new JsonResponse($body, $code);
$http = new Http($request, $response);

The astute of you, however, will have noticed that the $response closure does not quite adhere to the PSR-17 ResponseFactoryInterface, as it actually receives a body before it gets the code and reason. Rest assured, this interface violation is only present here at the constructor – the Http::createResponse method is implemented as expected, and is done so that you can format as per your requirements.

APIs as URIs

Most HTTP "client" libraries will have some sort of method signature that asks for a URL/endpoint as a string, and provide optional parameters for a query (GET parameters). Often, this can lead to improper use the library by developers placing query parameters directly into the URL/endpoint parameter, using varrying methods of string concatenation and interpolation, leading to unstandardized, and messy code.

In an attempt to prevent this sort of inconsistency from happening (among others you may have experienced), URLs have been done away with in favour of first-class UriInterface instances.

# Store this or a factory for it anywhere along with other API details, like
# auth, headers, etc.!
$github = new Uri('https://api.github.com');

Seems underwhelming at first, but when used with an Http instance configured with some kind of JSON response, we get a fluid and well read set of API calls in our code.

Making Requests

Continuing with the examples from above, let's make a request for a GitHub user profile with ease and style.

$user = $http
  ->get($github->withPath('users/tpope'))
  ->getPayload();

This reads exceptionally well and can be further abstracted as needed, providing an experience much closer to Redis, query builders, and fluid interfaces alike, as opposed to traditional HTTP "client" packages.

Motivation

Yeah, but like ... why?

Good question, and similarly answered; why not? More specifically, and perhaps more seriously, HTTP clients in PHP appear to have a history of being designed very similarily, create their own array-based configuartions, throw exceptions for valid HTTP responses, and have a "top down" approach to creating a client (e.g., new Client('http://api.acme.io')) that can force you to need multiple instances for multiple APIs, all resulting in a cumbersome developer & maintenance experience.

Another point that this library attempts to address is The "Client". We've all had the experience of importing multiple Client classes, aliasing and extending all over the place. "Client" is an amiguous term, similarly to data, and params, essentially meaningless and not even HTTP specific (a client of what?). Inspired by Go's net package, Http just seems like a perfect fit.

Aside from design & usage differences, Net attempts to maintain a slim, concrete, no dependency (PSRs aside), based API that won't result in dependency conflicts during a large-scale project upgrade, that can often happen with legacy projects catching up with latest versions.