class Mongrel::CGIWrapper

The beginning of a complete wrapper around Mongrel’s internal HTTP processing system but maintaining the original Ruby CGI module. Use this only as a crutch to get existing CGI based systems working. It should handle everything, but please notify me if you see special warnings. This work is still very alpha so I need testers to help work out the various corner cases.

The CGIWrapper.handler attribute is normally not set and is available for frameworks that need to get back to the handler. Rails uses this to give people access to the RailsHandler#files (DirHandler really) so they can look-up paths and do other things with the files managed there.

In Rails you can get the real file for a request with:

path = @request.cgi.handler.files.can_serve(@request['PATH_INFO'])

Which is ugly but does the job. Feel free to write a Rails helper for that. Refer to DirHandler#can_serve for more information on this.

Constants

REMOVED_KEYS: these are stripped out of any keys passed to CGIWrapper.header function

Attributes

default_really_final [RW]

Set this to false if you want calls to CGIWrapper.out to not actually send the response until you force it.

handler [RW]

options [R]

Public Class Methods

new (request, response, *args)

Source

# File lib/mongrel/cgi.rb, line 42
def initialize(request, response, *args)
  @request = request
  @response = response
  @args = *args
  @input = request.body
  @head = {}
  @out_called = false
  @default_really_final=true
  super(*args)
end

Takes an HttpRequest and HttpResponse object, plus any additional arguments normally passed to CGI. These are used internally to create a wrapper around the real CGI while maintaining Mongrel’s view of the world.

Calls superclass method

Public Instance Methods

args ()

Source

# File lib/mongrel/cgi.rb, line 160
def args
  @args
end

Used to wrap the normal args variable used inside CGI.

env_table ()

Source

# File lib/mongrel/cgi.rb, line 165
def env_table
  @request.params
end

Used to wrap the normal env_table variable used inside CGI.

header (options = "text/html")

Source

# File lib/mongrel/cgi.rb, line 60
def header(options = "text/html")
  # if they pass in a string then just write the Content-Type
  if options.class == String
    @head['Content-Type'] = options unless @head['Content-Type']
  else
    # convert the given options into what Mongrel wants
    @head['Content-Type'] = options['type'] || "text/html"
    @head['Content-Type'] += "; charset=" + options['charset'] if options.has_key? "charset" if options['charset']
    
    # setup date only if they use nph
    @head['Date'] = CGI::rfc1123_date(Time.now) if options['nph']

    # setup the server to use the default or what they set
    @head['Server'] = options['server'] || env_table['SERVER_SOFTWARE']

    # remaining possible options they can give
    @head['Status'] = options['status'] if options['status']
    @head['Content-Language'] = options['language'] if options['language']
    @head['Expires'] = options['expires'] if options['expires']

    # drop the keys we don't want anymore
    REMOVED_KEYS.each {|k| options.delete(k) }

    # finally just convert the rest raw (which puts 'cookie' directly)
    # 'cookie' is translated later as we write the header out
    options.each{|k,v| @head[k] = v}
  end

  # doing this fakes out the cgi library to think the headers are empty
  # we then do the real headers in the out function call later
  ""
end

The header is typically called to send back the header. In our case we collect it into a hash for later usage.

nph – Mostly ignored. It’ll output the date. connection – Completely ignored. Why is CGI doing this? length – Ignored since Mongrel figures this out from what you write to output.

out (options = "text/html", really_final=@default_really_final) { ||| "")| ... }

Source

# File lib/mongrel/cgi.rb, line 127
def out(options = "text/html", really_final=@default_really_final)
  if @out_called || !really_final
    # don't do it more than once or if it's not the really final call
    return
  end

  header(options)

  @response.start status do |head, body|
    send_cookies(head)
    
    @head.each {|k,v| head[k] = v}
    body.write(yield || "")
  end

  @out_called = true
end

The dumb thing is people can call header or this or both and in any order. So, we just reuse header and then finalize the HttpResponse the right way. Status is taken from the various options and converted to what Mongrel needs via the CGIWrapper.status function.

We also prevent Rails from actually doing the final send by adding a second parameter “really_final”. Only Mongrel calls this after Rails is done. Since this will break other frameworks, it defaults to a different setting for rails (false) and (true) for others.

send_cookies (to)

Source

# File lib/mongrel/cgi.rb, line 98
def send_cookies(to)
  # convert the cookies based on the myriad of possible ways to set a cookie
  if @head['cookie']
    cookie = @head['cookie']
    case cookie
    when Array
      cookie.each {|c| to['Set-Cookie'] = c.to_s }
    when Hash
      cookie.each_value {|c| to['Set-Cookie'] = c.to_s}
    else
      to['Set-Cookie'] = options['cookie'].to_s
    end
    
    @head.delete('cookie')
  end
  
  # @output_cookies seems to never be used, but we'll process it just in case
  @output_cookies.each {|c| to['Set-Cookie'] = c.to_s } if @output_cookies
end

Takes any ‘cookie’ setting and sends it over the Mongrel header, then removes the setting from the options. If cookie is an Array or Hash then it sends those on with .to_s, otherwise it just calls .to_s on it and hopefully your “cookie” can write itself correctly.

status ()

Source

# File lib/mongrel/cgi.rb, line 148
def status
  if not @status
    stat = @head["Status"]
    stat = stat.split(' ')[0] if stat

    @status = stat || "200"
  end

  @status
end

Computes the status once, but lazily so that people who call header twice don’t get penalized. Because CGI insists on including the options status message in the status we have to do a bit of parsing.

stdinput ()

Source

# File lib/mongrel/cgi.rb, line 170
def stdinput
  @input
end

Used to wrap the normal stdinput variable used inside CGI.

stdoutput ()

Source

# File lib/mongrel/cgi.rb, line 175
def stdoutput
  STDERR.puts "WARNING: Your program is doing something not expected.  Please tell Zed that stdoutput was used and what software you are running.  Thanks."
  @response.body
end

The stdoutput should be completely bypassed but we’ll drop a warning just in case