ReactPHP ft. Viewi 2

React\Http\Message\Response is now final and does not allow extending anymore.

This application demonstrates Viewi integration with ReactPHP.

Requirements

php >= 8.0

react/http

viewi/viewi

react/async

Node.js >= 12 (for building assets)

Architecture design

ReactPHP will serve our API.

And Viewi will be responsible for rendering HTML pages on the client-side as a front-end application. But also it will be responsible for rendering HTML on the server-side (SSR). In both cases, Viewi application can consume the server's API using HttpClient:

• In the browser - AJAX
• During SSR - simulate a request and pass it to the ReactPHP application (direct invocation)

(ReactPHP - API) <-- data --> (Viewi application)

Demo Overview

Click here: Demo Overview

Integration steps

• Install ReactPHP HTTP composer require react/http
• Install ReactPHP Async composer require react/async
• Install Viewi composer require viewi/viewi
• Create server.php file for server code
• Create a public folder for serving static and public files
• Create a demo application if you don't have any vendor/bin/viewi new

Configuration

Couple of important settings to consider here.

To run Viewi application you need to tell Viewi where to put its compiled files. It should be a public folder.

In this case, it is a public folder:

__DIR__ . '/../public/'

Public url path to resolve assets, in this case it's an empty string '' (means assets base URL is http://localhost/)

NPM watch setting, you can either use it, or you can disable it.

->watchWithNPM(true) or ->watchWithNPM(false)

Setting it to false will trigger a build process on the first request.

The final config should look something like this:

viewi-app\config.php

<?php

use Viewi\AppConfig;

$d = DIRECTORY_SEPARATOR;
$viewiAppPath = __DIR__ . $d;
$componentsPath =  $viewiAppPath . 'Components';
$buildPath = $viewiAppPath . 'build';
$jsPath = $viewiAppPath . 'js';
$assetsSourcePath = $viewiAppPath . 'assets';
$publicPath = __DIR__ . $d . '..' . $d . 'public';
$assetsPublicUrl = '';

return (new AppConfig('react'))
    ->buildTo($buildPath)
    ->buildFrom($componentsPath)
    ->withJsEntry($jsPath)
    ->putAssetsTo($publicPath)
    ->assetsPublicUrl($assetsPublicUrl)
    ->withAssets($assetsSourcePath)
    ->combine(false)
    ->minify(false)
    ->developmentMode(true)
    ->buildJsSourceCode()
    ->watchWithNPM(true);

Implementation

Remove your index.php which contains Viewi standalone application code, you won't need it.

Serve static files from a public folder

If you don't have a middleware for static files or your application is not behind any of the web servers (Apache, Nginx, etc.) you will need StaticFilesMiddleware (Not production-ready, only for demo purposes).

App\Middleware\StaticFilesMiddleware.php

<?php

namespace App\Middleware;

use React\Http\Message\Response;

class StaticFilesMiddleware
{
    private string $directory;

    public function __construct(string $directory)
    {
        $this->directory = $directory;
    }

    public function __invoke(\Psr\Http\Message\ServerRequestInterface $request, callable $next)
    {
        $filePath = $request->getUri()->getPath();
        $file = $this->directory . $filePath;
        if (file_exists($file) && !is_dir($file)) {
            $fileExt = pathinfo($file, PATHINFO_EXTENSION);
            $contentType = 'text/text';
            switch ($fileExt) {
                case 'js': {
                        $contentType = 'application/javascript';
                        break;
                    }
                case 'json': {
                        $contentType = 'application/json';
                        break;
                    }
                case 'css': {
                        $contentType = 'text/css';
                        break;
                    }
                case 'ico': {
                        $contentType = 'image/x-icon';
                        break;
                    }
            }
            return new Response(200, ['Content-Type' => $contentType], file_get_contents($file));
        }
        return $next($request);
    }
}

And use it like this:

new React\Http\HttpServer(
    new StaticFilesMiddleware(__DIR__ . '/public') // path to your public folder
...

Request handler

The most important of the application is to handle requests. In this case, we need to handle two parts:

• Requests that should be handled by Viewi
• The rest of the requests should be handled by API actions

Viewi has a built-in router and is used in this example. But it's not required, you can use any router that you like and use it with Viewi as well.

viewi-app\viewi.php contains your Viewi application instance initialization. Using that instance you can get router.

use Viewi\App;

$config = require  __DIR__ . '/config.php';
$publicConfig = require  __DIR__ . '/publicConfig.php';

$app = new App($config, $publicConfig);

$router = $app->router();

public function __invoke(ServerRequestInterface $request)
{
    $match = $this->router->resolve($request->getUri()->getPath(), $request->getMethod());

It will contain the following information:

• $match['item']: instance of Viewi\Routing\RouteItem
  • action: string|callable - class name or callable
• $match['params']: array of matched arguments from the path (/api/posts/{id} -> ['id' => '5'])

Next part is to handle the action. If it's callable and not a string - just call the handler:

/** @var RouteItem $route */
$route = $match['route'];
$action = $route->action;
if (is_callable($action) && !is_string($action)) {
    if ($match['params']) {
        $request = $request->withAttribute('params', $match['params']);
    }
    return $action($request);
}

If not, that means we have Viewi component and we need to call render method:

use Viewi\Components\Http\Message\Request;
// ...
if ($action instanceof ComponentRoute) {
    $viewiRequest = new Request($request->getUri()->getPath(), strtolower($request->getMethod()));
    $response = $this->viewiApp->engine()->render($action->component, $match['params'], $viewiRequest);
}

The full code is located here App\Middleware\RequestsHandlerMiddleware.php

Use it as a regular middleware:

$viewiRequestHandler = new RequestsHandlerMiddleware();
...
$http = new React\Http\HttpServer(
    new StaticFilesMiddleware(__DIR__ . '/public'),
    $viewiRequestHandler
);

Viewi React bridge

By default, Viewi uses its own internal request/response handler. To tell Viewi that we need to handle request/response with ReactPHP we need to set up a bridge:

interface IViewiBridge
{
    // file_exists - Checks whether a file or directory exists
    function file_exists(string $filename): bool;
    
    // is_dir - Tells whether the filename is a directory
    function is_dir(string $filename): bool;
    
    // file_get_contents - Reads entire file into a string
    function file_get_contents(string $filename): string | false;
    
    // request - Server-side internal request handler. Request that comes from Viewi component.
    function request(Request $request): mixed;
}

Default bridge: Viewi\Bridge\DefaultBridge.

We can reuse some of the methods and override only a request handler.

For the request method we will need RequestsHandlerMiddleware to process internal requests. Let's inject it in the constructor:

class ViewiReactBridge extends DefaultBridge
{
    /**
     * 
     * @var callable
     */
    private $requestHandler;

    public function __construct($requestHandler)
    {
        $this->requestHandler = $requestHandler;
    }

Next, we need to create an instance of React\Http\Message\ServerRequest and pass it to the RequestsHandlerMiddleware:

public function request(\Viewi\Components\Http\Message\Request $request): mixed
{
    $reactRequest = new \React\Http\Message\ServerRequest(
            $request->method,
            $request->url,
            $request->headers,
            $request->body ? json_encode($request->body) : ''
        );
    $response = ($this->requestHandler)($reactRequest);
    if ($response instanceof PromiseInterface) {
        $response = await($response);
    }

Also, the url could be external and we need to make a real HTTP call, le's use \React\Http\Browser:

public function request(\Viewi\Components\Http\Message\Request $request): mixed
{
    if ($request->isExternal) {
        $browser = new \React\Http\Browser();
        $promise = $browser->request($request->method, $request->url, $request->headers, $request->body ? json_encode($request->body) : '');
        $response = await($promise);
        return @json_decode($response->getBody(), true);
    }
// ...

At the end, the request method should return either a \Viewi\Components\Http\Message\Response instance, or just any raw data (array, model class instance, anything that is serializable into JSON).

To set up a new bridge for Viewi application we will use Viewi factory:

$viewiReactBridge = new ViewiReactBridge($viewiRequestHandler);
// \Viewi\App
$app->factory()->add(IViewiBridge::class, function () use ($viewiReactBridge) {
    return $viewiReactBridge;
});

Full code:

App\Bridge\ViewiReactBridge.php

<?php

namespace App\Bridge;

use App\Message\RawJsonResponse;
use React\Http\Message\ServerRequest;
use React\Promise\PromiseInterface;
use Viewi\Bridge\DefaultBridge;
use Viewi\Components\Http\Message\Request;

use function React\Async\await;

class ViewiReactBridge extends DefaultBridge
{
    /**
     * 
     * @var callable
     */
    private $requestHandler;

    public function __construct($requestHandler)
    {
        $this->requestHandler = $requestHandler;
    }

    public function request(Request $request): mixed
    {
        if ($request->isExternal) {
            $browser = new \React\Http\Browser();
            $promise = $browser->request($request->method, $request->url, $request->headers, $request->body ? json_encode($request->body) : '');
            $response = await($promise);
            return @json_decode($response->getBody(), true);
        }

        $reactRequest = new ServerRequest($request->method, $request->url, $request->headers, $request->body ? json_encode($request->body) : '');
        $response = ($this->requestHandler)($reactRequest);
        if ($response instanceof PromiseInterface) {
            $response = await($response);
        }

        /**
         * @var \React\Http\Message\Response $response
         */

        $viewiResponse = new \Viewi\Components\Http\Message\Response($request->url, $response->getStatusCode(), $response->getReasonPhrase(), $response->getHeaders());
        if ($response instanceof RawJsonResponse) {
            $viewiResponse->body = $response->getData();
        } else {
            $data = $response->getBody()->__toString();
            if ($data) {
                $viewiResponse->body = @json_decode($data, true);
            }
        }

        return $viewiResponse;
    }
}

Using react/async

In order to convert asynchronous response from ReactPHP action and pass it to Viewi we need to extract it from promise as a \React\Http\Message\Response instance. To do that we will use await function:

use React\Promise\PromiseInterface;
use function React\Async\await;
// ...
if ($response instanceof PromiseInterface) {
    $response = await($response);
}

Extracting data from HTTP call for components

In ReactPHP, response by default implements Psr\Http\Message\ResponseInterface, therefore the content is always a string (html or json).

But if you want to use typed function arguments inside of callbacks from HttpClient requests (see example), it's recommended to use RawJsonResponse declared in App\Message\RawJsonResponse.php

$http->get('/api/posts/45')->then(
    function (PostModel $post) {
        $this->post = $post;
    },
...

RawJsonResponse will preserve the original data without losing the type.

server.php

The last step is to set up your server:

<?php

// php server.php

use App\Bridge\ViewiReactBridge;
use App\Controller\AuthSessionAction;
use App\Controller\AuthTokenAction;
use App\Controller\PostsAction;
use App\Controller\PostsActionAsync;
use App\Middleware\RequestsHandlerMiddleware;
use App\Middleware\StaticFilesMiddleware;
use Viewi\Bridge\IViewiBridge;

require __DIR__ . '/vendor/autoload.php';

/**
 * @var \Viewi\App
 */
$viewiApp = include __DIR__ . '/viewi-app/viewi.php';
$router = $viewiApp->router();
$viewiRequestHandler = new RequestsHandlerMiddleware($router, $viewiApp);

$viewiReactBridge = new ViewiReactBridge($viewiRequestHandler);
$app->factory()->add(IViewiBridge::class, function () use ($viewiReactBridge) {
    return $viewiReactBridge;
});


$router->register('get', '/api/posts/{id}', new PostsAction());
$router->register('get', '/api/posts/{id}/async/{ms?}', new PostsActionAsync());
$router->register('post', '/api/authorization/session', new AuthSessionAction());
$router->register('post', '/api/authorization/token/{valid}', new AuthTokenAction());

// include viewi routes
include __DIR__ . '/viewi-app/routes.php';

$http = new React\Http\HttpServer(
    new StaticFilesMiddleware(__DIR__ . '/public'),
    $viewiRequestHandler
);

$socket = new React\Socket\SocketServer(isset($argv[1]) ? $argv[1] : '127.0.0.1:8080');
$http->listen($socket);

echo 'Listening on ' . str_replace('tcp:', 'http:', $socket->getAddress()) . PHP_EOL;

Build Viewi application

Viewi application is not about PHP. It is also a fully capable JavaScript application.

To set it up you need to perform simple steps.

If you are using vendor/bin/viewi new that may not be necessary.

But if you are cloning this repository you will need to install NPM packages.

Assuming that you have installed composer packages:

cd viewi-app/js

npm install

Wait for the installation.

Watching mode

Watching mode will monitor your Viewi application for changes and will trigger a build process automatically.

Go to your Viewi application js folder

cd viewi-app/js

Run NPM watch command

npm run watch

You will need to keep two terminals open in order to run this and ReactPHP server for development.

Watch mode is optional, please follow https://viewi.net/docs/watch-mode for more.

Step by step

• Instantiate \Viewi\App and keep int a variable
  • $viewiApp = include __DIR__ . '/viewi-app/viewi.php';
• Get Viewi router if using
  • $router = $viewiApp->router();
• Instantiate RequestsHandlerMiddleware and keep it in a variable
  • $viewiRequestHandler = new RequestsHandlerMiddleware($router, $viewiApp);
• Create a bridge for Viewi:
  • $viewiReactBridge = new ViewiReactBridge($viewiRequestHandler);

$app->factory()->add(IViewiBridge::class, function () use ($viewiReactBridge) {
    return $viewiReactBridge;
});

• Register your actions:
  • For example: $router->register('get', '/api/posts/{id}', new PostsAction());
• Include Viewi routes (for components)
  • include __DIR__ . '/viewi-app/routes.php';
• Create a http server
  • $http = new React\Http\HttpServer(
  • pass StaticFilesMiddleware if needed
  • pass $viewiRequestHandler middleware
• Create a socket server
  • $socket = new React\Socket\SocketServer(isset($argv[1]) ? $argv[1] : '127.0.0.1:8080');
• Run the server by listening to the socket events:
  • $http->listen($socket);

And you can run it: php server.php

Things to improve:

• Package library.
• Router helper ($router->get(...), etc).
• Router params injection into the action: 'get', '/api/posts/{id}', function (ServerRequestInterface $request, int $id)

Thanks and feel free to review, ask questions, contribute in any way.

Links:

Discussions

Viewi Twitter

ReactPHP Twitter

Viewi Website

ReactPHP Website

Viewi Github

ReactPHP Github

License

MIT License

Copyright (c) 2020-present Ivan Voitovych

Please see LICENSE for license text