Simplify the interface for most cowboy_req functions. They all return
a single value except the four body reading functions. The reply functions
now only return a Req value.
Access functions do not return a Req anymore.
Functions that used to cache results do not have a cache anymore.
The interface for accessing query string and cookies has therefore
been changed.
There are now three query string functions: qs/1 provides access
to the raw query string value; parse_qs/1 returns the query string
as a list of key/values; match_qs/2 returns a map containing the
values requested in the second argument, after applying constraints
and default value.
Similarly, there are two cookie functions: parse_cookies/1 and
match_cookies/2. More match functions will be added in future commits.
None of the functions return an error tuple anymore. It either works
or crashes. Cowboy will attempt to provide an appropriate status code
in the response of crashed handlers.
As a result, the content decode function has its return value changed
to a simple binary, and the body reading functions only return on success.
This should have been done a *long* time ago, back when I initially
added Websocket support. This is the first part of two in improving
loop handler support with regards to socket closure.
Reason may include: {normal, shutdown} for the most normal shutdown,
{normal, timeout} for a loop handler timeout shutdown, or {error, _}
if an error occured.
First step in making all methods and header names binaries to
get rid of many inconsistencies caused by decode_packet/3.
Methods are all binary now. Note that since they are case
sensitive, the usual methods become <<"GET">>, <<"POST">> and so on.
