NAME
    Apache::JAF -- mod_perl and Template-Toolkit web applications framework

SYNOPSIS
    controller -- mod_perl module that drives your application
         package Apache::JAF::MyJAF;
         use strict;
         use JAF::MyJAF; # optional
         use Apache::JAF;
         our @ISA = qw(Apache::JAF);

         # determine handler to call 
         sub setup_handler {
           my ($self) = @_;
           # the page handler for every uri for sample site is 'do_index'
           # you should swap left and right || parts for real application
           my $handler = 'index' || shift @{$self->{uri}};
           return $handler;
         }

         sub site_handler {
           my ($self) = @_;
           # common stuff before handler is called
           $self->{m} = JAF::MyJAF->new(); # create modeller -- if needed
           $self->SUPER::site_handler();
           # common stuff after handler is called
           return $self->{status}
         }
         1;

    page handler -- controller's method that makes one (or may be several)
    pages
         sub do_index {
           my ($self) = @_;
           # page handler must fill $self->{res} hash that process with template
           $self->{res}{test} = __PACKAGE__ . 'test';
           # and return Apache constant according it's logic
           return OK;
         }

    modeller -- module that encapsulates application business-logic
         package JAF::MyJAF;
         use strict;
         use DBI;
         use JAF;
         our @ISA = qw(JAF);

         sub new {
           my ($class, $self) = @_;
           $self->{dbh} = DBI->connect(...);
           return bless $self, $class;
         }
         1;

    Apache configuration (httpd.conf)
          DocumentRoot /examples/site/data
          <Location />
            <Perl>
              use lib qw(/examples/site/modules);
              use Apache::JAF::MyJAF;
            </Perl>
            SetHandler perl-script
            PerlHandler Apache::JAF::MyJAF
            PerlSetVar Apache_JAF_Templates /examples/site/templates
            PerlSetVar Apache_JAF_Modules /examples/site/modules/Apache/JAF/MyJAF/pages
            PerlSetVar Apache_JAF_Compiled /tmp
          </Location>

DESCRIPTION
  Introduction

    Apache::JAF is designed for creation web applications based on MVC
    (Model-View-Controller) concept.

    *   *Modeller* is JAF descendant

    *   *Controller* is Apache::JAF descendant

    *   and the *Viewer* is set of the templates using Template-Toolkit
        markup syntax

    This separation heavily simplifies dynamic site developmet by designers
    and programmers team. Each of the programmers working on own part of the
    project writing separate controller's parts and designers are working on
    visual presentation of templates.

  Suggested file structure

    Suggested site's on-disk structure is:

      site
       |
       +-- data
       |
       +-- modules
       |
       +-- templates

    *data*
        document_root for site. All static files such JavaScripts, pictures,
        CSSs and so on mus be placed here

    *modules*
        Storage place for site modules -- must be in "@INC"'s

    *templates*
        Here where you have to place your site templates. Framework is
        designed to reproduce site-structure in this folder. It's just like
        document_root for static site.

  Request processing pipeline

    The "Apache::JAF::handler" intercepts every request for specified
    location, and process it own way:

    1   If requested file exists on disk there is nothing happened. The
        handle throws request away with "DECLINE".

    2   Otherwise instance of Apache::JAF's descendant is created and
        "setup_handler" method is called. You must override this method and
        return determined handler name. Usually it's first part of uri or
        just "index". Also handlers from "Apache_JAF_Modules" folder are
        loaded into package's namespace.

    3   Then goes "site_handler" calling. If you have common tasks for every
        handler you have to override it. "site_handler" calls your own
        handler. It's name returned by "setup_handler". Usually this
        "mini-handler" is *very* simple. It have to be implemented as
        package method with "do_*<handler name>*" name. You have to fill
        "$self->{res}" hash with result and return Apache constant according
        to handler's logic ("OK", "NOT_FOUND", "FORBIDDEN" and so on). The
        sample is shown in the section on "SYNOPSIS".

    4   If result of previous step return OK, and "$self->{type}" property
        is "text/*" result of processing template is printing to th client.
        If type of result is not text, then one more method must be
        implemented: "on_send_*<handeler name>*_data". It have to print
        binary data back to the client. This way you may create handlers for
        dynamic generation of images, MS Excel workbooks and any other type
        of data.

  Apache::JAF descendant methods

    setup_handler
        *blah-blah-blah*

    site_handler
        *blah-blah-blah*

  Implementing handlers

    *blah-blah-blah*

  Templates structure and syntax

    Template for specific handler consists of:

    1 default.inc
        Common "[% BLOCK %]"s for all site templates. Processed before
        header and main tamplate.

    2 header.inc
        Header template. Processed before main handler's template.

    3 *<handler name>*.html
        Main handler's template.

    4 footer.inc
        Footer template. Processed after main handler's template.

    Default names and extensions are shown. All of them are configurable in
    processing handler methods. For example you have to disable processing
    header and footer for handler that produces not "text/*" content.

    Templates syntax is described at
    http://www.template-toolkit.org/docs/plain/Manual/.

CONFIGURATION
    Apache_JAF_Prefix
        Number of uri parts (between slashes) or path that must be removed
        from request uri. Useful for implementing dynamic part of almost
        static site. It's simplifies page handlers names.

    Apache_JAF_Templates
        Path to templates folder. Several paths may be separated by
        semicolon. *Win32 note*: This separator works too. Don't get
        confused with full paths with drive letters.

    Apache_JAF_Modules
        Path to page handlers folder. By default it's controller location
        plus "/pages".

    Apache_JAF_Compiled
        Path to compiled templates folder. Default is "/tmp". Saving
        compiled templates on disk dramatically improves overall site
        performance.

    Apache_JAF_Debug
        Application's debug level. The amount of debug info written to the
        Apache error_log. Ranges from 0 to 10.

         0: critical errors only
         1: request processing line
         2: client request
         3: response headers
         4: template variables
         5-8: not used (for future enchancements)
         9: loading additional handlers
         10: processed template

        Also this setting affecting page-handlers loading. If debug level is
        0 -- handlers are loaded only on server-start. Else handlers loaded
        on every request. That simplifies development process but increases
        request processing time. So it's not good to set debug level greater
        than 0 in production environment.

        *Note:* This setting is overrided by setting "$self->{debug_level}".

SEE ALSO
    *   mod_perl -- Perl and Apache integration project
        (http://perl.apache.org)

    *   Template-Toolkit -- template processing system (http://www.tt2.org)

    *   examples/* -- sample site driven by Apache::JAF

    *   http://jaf.webzavod.ru -- Apache::JAF companion website

AUTHOR
    Greg "Grishace" Belenky <greg@webzavod.ru>

COPYRIGHT
     Copyright (C) 2001-2003 Greg Belenky
     Copyright (C) 2002-2003 WebZavod (http://www.webzavod.ru) programming team

    This module is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself.

