add doc for middleware usage in "dispatch" event

[samsonasik]

#92

[weierophinney]

@samsonasik Please create a new cookbook/ subtree in the documentation source, and add this. Then, in mkdocs.yml, create a Cookbook subsection, with this as the only sub-document.

Thanks!

[samsonasik]

@weierophinney done ;). moved to cookbook and updated mkdocs.yml

[danizord]

I think that you could pass an empty closure as third parameter to the middleware, so that if the middleware return $next($req, $res), then $result will be null, and if the middleware return $response, then $result will be a response. In case it returns a response, you can convert it back to Zend\Http and return it (short-circuiting).

[samsonasik]

Done ;)

[danizord]

@samsonasik now in listener, you can add this:

if ($result instanceof \Psr\Http\Message\ResponseInterface) {
    return Psr7Response::toZend($result);
}

So that the middleware becomes able to short-circuit, for example some AuthorizationMiddleware can return a 403 response if not authorized. :)

[samsonasik]

@danizord done ;) Thank you ;)

[weierophinney]

Thanks, @samsonasik !