在zend expressive 2中将参数从管道中间件传递到工厂类

Question

I want to connect to different database according to URL. I try to set request attribute and get that attribute in *Factory.php .
I edit autoload/pipeline.php :

<?php
$app->pipe(UrlHelperMiddleware::class);
$app->pipe(\App\Action\Choose::class);
$app->pipeDispatchMiddleware();

in Choose.php I implement process() like this:

<?php
public function process(ServerRequestInterface $request, DelegateInterface $delegate)
{
    /** @var RouteResult $route */
    $route = $request->getAttribute(RouteResult::class);
    if ($route->getMatchedRouteName() == 'FirstRoute' or $route->getMatchedRouteName() == 'SecondRoute') {
        $request = $request->withAttribute('DB_NAME', $route->getMatchedParams()['param']);
    }
    return $delegate->process($request);
}

The main problem is in *Factory.php I don't access to request.
Any try to access to Interop\\Http\\ServerMiddleware\\MiddlewareInterface or Psr\\Http\\Message\\ServerRequestInterface in *Factory.php raises same error.

Is there any way pass parameter from pipeline middleware to factory class?

Answer 1

If you use zend-servicemanager you can try this (just a theory, not tested):

Create 2 database factories in your config: 'db.connection.a' => DbFactoryA::class, 'db.connection.b' => DbFactoryB::class,

Then depending on the route, in Choose you load the connection you need and pass it to the container as the default connection. $db = $container->get('db.connection.a'); $container->setService('db.connection.default', $db);

And now in all following middleware you can grab the default connection.

UPDATE:

As mentioned in the comments, this requires the container to be injected which is considered bad practice. How about you wrap the two in a common connection class and set the required from Choose :

class Connection
{
    private $connection;

    /**
     * @var ConnectionInterface
     */
    private $db_a;

    /**
     * @var ConnectionInterface
     */
    private $db_b;

    public function __construct(ConnectionInterface $a, ConnectionInterface $b)
    {
        $this->db_a = $a;
        $this->db_b = $b;
    }

    public function setConnection($connection)
    {
        if ($connection === 'a') {
            $this->connection = $this->db_a;
            return;
        }

        $this->connection = $this->db_b;
    }

    public function getConnection()
    {
        return $this->connection;
    }
}

Or you can inject only the config and create the database connection that's really needed. Store it in a property for caching (like the container does).