Exception
7 years ago
Handler
7 years ago
Plugins
7 years ago
Setup
7 years ago
CommandBus.php
7 years ago
Middleware.php
7 years ago
CommandBus.php
69 lines
| 1 | <?php |
| 2 | |
| 3 | namespace League\Tactician; |
| 4 | |
| 5 | use League\Tactician\Exception\InvalidCommandException; |
| 6 | use League\Tactician\Exception\InvalidMiddlewareException; |
| 7 | |
| 8 | /** |
| 9 | * Receives a command and sends it through a chain of middleware for processing. |
| 10 | * |
| 11 | * @final |
| 12 | */ |
| 13 | class CommandBus |
| 14 | { |
| 15 | /** |
| 16 | * @var callable |
| 17 | */ |
| 18 | private $middlewareChain; |
| 19 | |
| 20 | /** |
| 21 | * @param Middleware[] $middleware |
| 22 | */ |
| 23 | public function __construct(array $middleware) |
| 24 | { |
| 25 | $this->middlewareChain = $this->createExecutionChain($middleware); |
| 26 | } |
| 27 | |
| 28 | /** |
| 29 | * Executes the given command and optionally returns a value |
| 30 | * |
| 31 | * @param object $command |
| 32 | * |
| 33 | * @return mixed |
| 34 | */ |
| 35 | public function handle($command) |
| 36 | { |
| 37 | if (!is_object($command)) { |
| 38 | throw InvalidCommandException::forUnknownValue($command); |
| 39 | } |
| 40 | |
| 41 | $middlewareChain = $this->middlewareChain; |
| 42 | return $middlewareChain($command); |
| 43 | } |
| 44 | |
| 45 | /** |
| 46 | * @param Middleware[] $middlewareList |
| 47 | * |
| 48 | * @return callable |
| 49 | */ |
| 50 | private function createExecutionChain($middlewareList) |
| 51 | { |
| 52 | $lastCallable = function () { |
| 53 | // the final callable is a no-op |
| 54 | }; |
| 55 | |
| 56 | while ($middleware = array_pop($middlewareList)) { |
| 57 | if (! $middleware instanceof Middleware) { |
| 58 | throw InvalidMiddlewareException::forMiddleware($middleware); |
| 59 | } |
| 60 | |
| 61 | $lastCallable = function ($command) use ($middleware, $lastCallable) { |
| 62 | return $middleware->execute($command, $lastCallable); |
| 63 | }; |
| 64 | } |
| 65 | |
| 66 | return $lastCallable; |
| 67 | } |
| 68 | } |
| 69 |