Add Last-Modified header to response

[ghost]

For better front end performance on first request, response should be sent with Last-Modified header.

When implementing please add a check for 304 responses (Response#isNotModified).

[lsmith77]

good point .. think we need to explore if to delegate responsibility for this to the data loader.
at the same time .. in my current application we are handling this via our custom Controller.

[lsmith77]

actually thinking about this some more .. when using file system caching it should be handled by the web server. when disabling caching i think the normal use case will be using a reverse proxy which again will automatically handle this.

so imho we should not handle this either.

as for cache headers this should be also be handled by the user .. either with a custom controller or via LiipCacheControlBundle.

[ghost]

actually thinking about this some more .. when using file system caching it should be handled by the web server.

Yes, but for the first request which hits the app we don't serve this header (we should).

when disabling caching i think the normal use case will be using a reverse proxy which again will automatically handle this.

I am not sure. Why the reverse proxy will handle it differently if original response doesn't contain this header?

[ghost]

Please reconsider this PR.

[lsmith77]

@MHeleniak: my point is more i guess .. its close to impossible to really properly handle this generically. cache validation is simply too application specific. the right solution is for users to extend the Controller and/or use LiipCacheControlBundle to set cache headers.

now one thing that we could think about is how the data loader could return such metadata back to the Controller ..

[LouTerrailloune]

Adding an option (or using a custom cache path resolver) to redirect after creation of the image cache would resolve this. First time we just generate image and redirect 301, next time the webserver returns the file directly.
I think a redirection if more than doanloading the content twice.

[lsmith77]

i have refactored the entire response creation quite a bit. so it should enable people to do whatever they need.