Forums Feature Suggestions /http* client functions and abstraction

; A simplistic SYNCHRONOUS HTTP request function. Returns the
; status code and body, but does not provide access to headers.
; For complex HTTP requests, use the asynchronous function.
;
; Returns <status code> [response body]
$httpreq(<method>, <full URI>, [biohuN], [body], [&outbin],
  [<Header: value>, ...])

Switches:
b: indicates that a body is provided. 
i: indicates that the body token is a binvar.
o: indicates that the outbin binvar is provided to store output.
   In this case, $httpreq returns ONLY the status code.
h: indicates that a list of "Header: value" parameters are provided.
uN: timeout the request after N seconds if there is no response.
    (XXX: support decimals or make this milliseconds?)

Example:
//echo -a Response: $httpreq(GET, http://example.org/res?q=foo, h, 
                                  Authorization: my-api-token)
; echos: Response: 200 SomeDataHere 

; Opens/closes an HTTP session.
; No error if the handle is already open.
/httpopen <handle>
/httpclose <handle>

; Starts a request but doesn't send it.
; Error if /httpstart was executed without matching /httpsend.
/httpstart [-os] <handle> <method> <full URI>
-o: open the handle if not already open
-s: call /httpsend immediately (no body/headers)

; Adds a header to a request
; Error if no pending /httpstart transaction exists.
/httpheader [-b] <handle> <header> <value>
-b: the value parameter is a binvar.

; Adds a body to a request
; Error if no pending /httpstart transaction exists.
/httpbody [-b] <handle> <body|&binvar>
-b: the body parameter is a binvar.

; Sends the last built request on handle
; Error if no pending /httpstart transaction exists.
/httpsend <handle>

; Handles a response from a request on a session
on HTTPRESPONSE:<handle>:<uri matchtext>:
  <comma separated matchtext statuscodes?>:/commands

The event would expose a few identifiers:

$httphandle - the handle of the session
$httpuri - the URI of the response (matches the URI of the
           resource we called in /httpstart)
$httpstatus - the status code
$httpheader(N/Name) - the Nth header in the response or the
                      header named Name if text is provided.
$httpbody - the response body

Possibly also /httpread <%var|&binvar> which would copy the
body into a var/binvar.

Full example usage:

alias makereq {
  httpstart -o mysession POST http://example.org/posts/create
  httpheader mysession Authorization: my-api-token
  httpbody mysession The body to send
  httpsend mysession
}

; Handle initial success response
on *:HTTPRESPONSE:mysession:*/posts/create:200: {
  ; more correct to use 2* as status code match
  echo -a Success! Creation data: $httpbody

  ; I can now make a follow-up request using the same session
  ; using any stored cookie data.
  httpstart $httphandle GET $httpheader(Post-URI)
  httpheader $httphandle Authorization: my-api-token
  httpsend $httphandle
}

; Handle follow-up request
on *:HTTPRESPONSE:mysession:*:2*: {
  echo -a Post body: $httpbody
}

; Handle failures
on *:HTTPRESPONSE:mysession:*:4*,5*: { ; handle 4xx 5xx responses
  echo -a Error occurred when retrieving $httpuri
}