#!/usr/bin/python
#
# Copyright (c) 2007-2008 by Fred Morris Consult, Seattle WA USA
#
# Author: Fred Morris
# Date: 25-Jan-2008
#
# Licensed under the Perl Artistic License: "under the same terms
# as Perl itself".

"""Concatenation Example

Usage: Called as a CGI Script

Demonstrates building a web page from three separate web pages by simple
concatenation.

The subtle deal with this one as opposed to the (true) nested example is
that all of the handlers are inner handlers. The prologue and epilogue are
build from the outer handler's template, the the outer handler's template
is disabled.

An additional subtlety of this one is that Prologue and Epilogue attempt
to do things with the outer response body before the (asynchronous) gate.
Therefore fetching the outer template asynchronously may (but is not
guaranteed to) produce anomalous behavior.

Parameters:
  None

Version:
    1.1

Modification History:

FWM 20-Feb-2008 ...; Fetch inner templates asynchronously.

"""

import sys
from snakestation.handlers import Nester, Inner

class Inner1 (Inner):

    TEMPLATE_NAME = 'Inner'
    ASYNCHRONOUS_TEMPLATE = True

class Inner2 (Inner):

    TEMPLATE_NAME = 'Inner2'
    ASYNCHRONOUS_TEMPLATE = True

class Prologue (Nester):

    TEMPLATE_NAME = None

    def post_template(self):
        """Everything before inner is our part of the response.

        A NOTE ON STYLE: if this was done in before_prepare(), we could
        safely enable ASYNCHRONOUS_TEMPLATE in Outer.
        """
        Nester.post_template(self)
        self.response.body_sent = True
        self.add_response(self.as_inner_response(self.response.body.split('%%inner%%')[0]))
        return

class Epilogue (Nester):

    TEMPLATE_NAME = None

    def post_template(self):
        """Everything after inner2 is our part of the response.

        A NOTE ON STYLE: if this was done in before_prepare(), we could
        safely enable ASYNCHRONOUS_TEMPLATE in Outer.
        """
        Nester.post_template(self)
        self.response.body_sent = True
        self.add_response(self.as_inner_response(self.response.body.split('%%inner2%%')[1]))
        return

class Outer (Nester):
    """A toplevel handler containing nested handlers."""

    TEMPLATE_NAME = 'Outer'
    # Uncommenting the following may produce an error because Prologue and
    # Epilogue access the body in post_template() which is before the gate.
    # ASYNCHRONOUS_TEMPLATE = True
    INNER_HANDLERS = (Prologue,Inner1,Inner2,Epilogue)

    def __init__(self,**args):
        """Send HTML"""
        Nester.__init__(self,**args)
        self.response.send_html()
        return

def main():

    handler = Outer()
    handler.template_map = {
        'Outer' :       'http://flame.m3047.inwa.net/snakestation/outer.html',
        'Inner' :       'http://flame.m3047.inwa.net/snakestation/inner.html',
        'Inner2':       'http://flame.m3047.inwa.net/snakestation/inner-2.html',
        }
    handler.main()

if __name__ == '__main__':
    main()