"""
WebEnvironment: A trivial wrapper for the cgi module
Usage:

from WebEnvironment import WebEnvironment
server = WebEnvironment()   #Initialize environment
server["get_or_post_var"]   #Dictionary lookup for GET or POST vars
server.REQUEST_METHOD       #Attribute lookup for environment vars
server.write(string)        #Output (send headers if not already sent)
server.file("head.html")    #Like server.write() for file contents
server.redirect(url string) #Call before headers sent
server.header(key, value)   #Set a header ("Content-Type":"text/html" by default)
server.sendHeaders()        #Force headers to be sent

"""
__author__ = "Patrick Lioi <patrick_at_lioi_dot_net>"
__date__ = "$Date: 2003/09/01 10:49:03 $"
__version__ = "$Revision: 1.0 $"

import cgi
import os


class WebEnvironment:
    _VARS = {}
    _headers = {"Content-Type":"text/html"}
    _ENV = {}
   
    def __init__(self):
        fieldStorage = cgi.FieldStorage()
        for key in fieldStorage.keys():
            self._VARS[key] = fieldStorage[key].value
        self.headers_sent = 0

    def sendHeaders(self):
        if self.headers_sent == 0:
            self.headers_sent = 1
            print "\n".join(
                ["%s: %s"%(key, value) 
                    for (key, value) in self._headers.items()])
            print

    def __getitem__(self, key):
        if not self._VARS.has_key(key):
            self._VARS[key]=""
        return self._VARS[key]
   
    def __setitem__(self, key, value):
        self._VARS[key] = value

    def __getattr__(self, name):
        if name in self._ENV:
            return self._ENV[name]
        else:
            self._ENV[name] = os.environ.get(name, '')
            return self._ENV[name]

    def header(self, key, value):
        self._headers[key]=value
        return self.headers_sent

    def redirect(self, location):
        self.header("Location", location)
        self.sendHeaders()

    def write(self, text):
        if not self.headers_sent:
            self.sendHeaders()
        print text

    def file(self, filename):
        self.write(file(filename).read())