# Rack::ForwardRequest gets caught by Rack::Recursive and redirects

# the current request to the app at +url+.

#

# raise ForwardRequest.new("/not-found")

#

class ForwardRequest < Exception

attr_reader :url, :env

def initialize(url, env = {})

@url = URI(url)

@env = env

@env[PATH_INFO] = @url.path

@env[QUERY_STRING] = @url.query if @url.query

@env[HTTP_HOST] = @url.host if @url.host

@env[HTTP_PORT] = @url.port if @url.port

@env[RACK_URL_SCHEME] = @url.scheme if @url.scheme

super "forwarding to #{url}"

end

end

# Rack::Recursive allows applications called down the chain to

# include data from other applications (by using

# <tt>rack['rack.recursive.include'][...]</tt> or raise a

# ForwardRequest to redirect internally.

class Recursive

def initialize(app)

@app = app

end

def call(env)

dup._call(env)

end

def _call(env)

@script_name = env[SCRIPT_NAME]

@app.call(env.merge(RACK_RECURSIVE_INCLUDE => method(:include)))

rescue ForwardRequest => req

call(env.merge(req.env))

end

def include(env, path)

unless path.index(@script_name) == 0 && (path[@script_name.size] == ?/ ||

path[@script_name.size].nil?)

raise ArgumentError, "can only include below #{@script_name}, not #{path}"

end

env = env.merge(PATH_INFO => path,

SCRIPT_NAME => @script_name,

REQUEST_METHOD => GET,

"CONTENT_LENGTH" => "0", "CONTENT_TYPE" => "",

RACK_INPUT => StringIO.new(""))

@app.call(env)

end

end