Add shortcut method for empty responses

[franzliedke]

StringResponse::blank(401), as that's another common use case (though now StringResponse may not be perfect).

It's called blank() because empty() cannot be used as method name until PHP 7. Any better ideas?

[weierophinney]

@franzliedke I'd argue a status 204 with a reason phrase "No Content" as defaults would make most sense here; you could then call the method noContent(). Thoughts?

[weierophinney]

Keep the original signature, but have the caller send a null value or an empty string.

[weierophinney]

Also, needs tests. :)

[franzliedke]

@weierophinney Took care of your feedback:
Parameter restored, method renamed, status code 204 by default, test added.

[weierophinney]

On review, I'm not sure this belongs in the StringResponse; there's no string!

I was commenting earlier on another PR, and I wonder if perhaps we could do this instead:

namespace Zend\Diactoros\Response;

use Zend\Diactoros\Response;
use Zend\Diactoros\Stream;

class NoContent extends Response
{
    public function __construct(array $headers = [], $status = 204)
    {
        $body = new Stream('php://memory', 'r');
        parent::__construct($body, $status, $headers);
    }
}

With usage like:

// Assuming "use Zend\Diactoros\Response\NoContent;
return new NoContent();

This provides the simplicity you're looking for, while keeping it semantically separate from the string-based response types. The constructor omits the body, and ensures the body is read-only. Since a "no content" status typically won't change, headers become the first argument, as those are the one aspect of the response that you may want to vary (e.g., to provide a location header, a link header, an authorization token, etc.).

Thoughts?

[franzliedke]

Why not.

I wouldn't change the arguments order, though, that would be confusing. Also, you may want to have empty responses for something like 201 Created or 202 Accepted, too, so changing the status is not so uncommon.

When only wanting to change the header, but not caring about the status, we could even provide an alternate static constructor, or people could just resort to this:

$response = (new NoContent)->withHeaders(...);

[weierophinney]

@franzliedke You've convinced me; go for it!

[franzliedke]

Can we call it EmptyResponse now?

[weierophinney]

@franzliedke sure.

[franzliedke]

Done as you suggested. Used php::temp instead, though, as that's what we had in the StringResponse class.

[weierophinney]

@franzliedke I'd chosen php://memory as the liklihood of an empty response ever going to the temp filesystem is essentially nil. :) Either will work, though; php://temp uses memory until memory limits are reached.

[franzliedke]

Ah, thanks for clarifying.

I think I'm done with this one. :)