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Apache-JAF-0.03
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/ Apache::JAF

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 is loaded into package's namespace.

  3. Then goes site_handler calling. If you have common tasks for every handler you can 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 "SYNOPSIS".

  4. If result of previous step return OK, and $self->{type} property is text/* result of processing template is printing to the 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

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.