This commit separates the documentation of the functions into
separate manual pages, with at least one example per function
and a lot more details about parameters, return values and
related functions and modules. It also includes a changelog
indicating when the function was added or changed.
The inspiration for this comes mainly from the PHP documentation
and feedback from users.
This is a large commit.
The rfc7230 test suite adds many tests from the RFC7230 document.
Gun has been updated quite a bit recently, which broke the Cowboy
suites. This is now fixed with this commit.
A new hook onfirstrequest has been added. It was very useful during
debugging of the test suites.
The initial process code has changed a little; more changes are
expected with the switch to maps for options.
This document lists all rules that Cowboy HTTP server will follow
after careful analysis of the RFC7230.
Do note that not all these rules are implemented or tested yet,
and that at the time of commit there may be rules that Cowboy will
ultimately not implement (for various reasons including performance
or leaving certain aspects up to the user code).
Now everywhere in Cowboy when we want to stop something we return
a 'stop' tuple instead of one of the many choices depending on
context that we had before.
This particular change affects middlewares, sub protocols and
REST handlers which were using 'halt' to stop processing.
The 'shutdown' atom has a specific meaning inside OTP. We are
instead going to use 'stop' which is pretty much the equivalent
of what we actually do. 'shutdown' is now reserved for future
special processes implementation.
Most examples returned 'Opts' as given by second argument to init. By
using '#state{}' the examples make it more clear that this is what is
being passed as 'State' to all subsequent callbacks (if any).
This change simplifies a little more the sub protocols mechanism.
Aliases have been removed. The renaming of loop handlers as long
polling handlers has been reverted.
Plain HTTP handlers now simply do their work in the init/2
callback. There is no specific code for them.
Loop handlers now follow the same return value as Websocket,
they use ok to continue and shutdown to stop.
Terminate reasons for all handler types have been documented.
The terminate callback is now appropriately called in all cases
(or should be).
Behaviors for all handler types have been moved in the module
that implement them. This means that cowboy_handler replaces
the cowboy_http_handler behavior, and similarly cowboy_loop
replaces cowboy_loop_handler, cowboy_websocket replaces
cowboy_websocket_handler. Finally cowboy_rest now has the
start of a behavior in it and will have the full list of
optional callbacks defined once Erlang 18.0 gets released.
The guide has been reorganized and should be easier to follow.
This set of changes is the first step to simplify the
writing of handlers, by removing some extraneous
callbacks and making others optional.
init/3 is now init/2, its first argument being removed.
rest_init/2 and rest_terminate/2 have been removed.
websocket_init/3 and websocket_terminate/3 have been removed.
terminate/3 is now optional. It is called regardless of
the type of handler, including rest and websocket.
The return value of init/2 changed. It now returns
{Mod, Req, Opts} with Mod being either one of the four
handler type or a custom module. It can also return extra
timeout and hibernate options.
The signature for sub protocols has changed, they now
receive these extra timeout and hibernate options.
Loop handlers are now implemented in cowboy_long_polling,
and will be renamed throughout the project in a future commit.
