response is empty

response is empty

[flyerhzm]

I wrote a middleware in rails. The codes is like:

  def initialize(app)
    @app = app
  end

  def call(env)
    status, headers, response = @app.call(env)
    return [status, headers, response] if response.empty?
    # other logic codes
  end

When I refresh the page, the response will be empty. So I puts
response.inspect, it's an empty array. Why?

So the other logic codes will not run, which need response.body. Is it
some reason about cache? How can I make response always not empty?

Re: response is empty

[Hongli Lai]

On Aug 16, 5:19 pm, flyerhzm <flyer...@gmail.com> wrote:
> I wrote a middleware in rails. The codes is like:
>
>   def initialize(app)
>     @app = app
>   end
>
>   def call(env)
>     status, headers, response = @app.call(env)
>     return [status, headers, response] if response.empty?
>     # other logic codes
>   end
>
> When I refresh the page, the response will be empty. So I puts
> response.inspect, it's an empty array. Why?
>
> So the other logic codes will not run, which need response.body. Is it
> some reason about cache? How can I make response always not empty?

According to the Rack spec:

"The Body must respond to each and must only yield String values. The
Body itself should not be an instance of String, as this will break in
Ruby 1.9."

In other words: the Body is *not* a string, and is usually an Array of
string. When you call response.empty? you're actually checking whether
the response is an empty array, and returning just that.

You should figure out how to do what you want with only an #each
method at your disposal.

Re: response is empty

[flyerhzm]

I think it's the problem of cache because if I disabled browser cache,
the issue is fixed.

Thanks

On Aug 18, 5:41 am, Hongli Lai <hon...@phusion.nl> wrote:
> On Aug 16, 5:19 pm, flyerhzm <flyer...@gmail.com> wrote:
>
>
>
> > I wrote a middleware in rails. The codes is like:
>
> >   def initialize(app)
> >     @app = app
> >   end
>
> >   def call(env)
> >     status, headers, response = @app.call(env)
> >     return [status, headers, response] if response.empty?
> >     # other logic codes
> >   end
>
> > When I refresh the page, the response will be empty. So I puts
> > response.inspect, it's an empty array. Why?
>
> > So the other logic codes will not run, which need response.body. Is it
> > some reason about cache? How can I make response always not empty?
>
> According to the Rack spec:
>
> "The Body must respond to each and must only yield String values. The
> Body itself should not be an instance of String, as this will break in
> Ruby 1.9."
>
> In other words: the Body is *not* a string, and is usually an Array of
> string. When you call response.empty? you're actually checking whether
> the response is an empty array, and returning just that.
>
> You should figure out how to do what you want with only an #each
> method at your disposal.