NAME
Apache::JAF -- mod_perl and Template-Toolkit web applications framework
SYNOPSIS
controller -- a mod_perl module that drives your application
package Apache::JAF::MyJAF;
use strict;
use JAF::MyJAF; # optional
# loading mini-handlers & templates during compilation time
use Apache::JAF (
handlers => '/examples/site/modules/Apache/JAF/MyJAF/pages/', # 'auto' if you want to use suggested file structure
templates => '/examples/site/templates/' # the same comment
);
our @ISA = qw(Apache::JAF);
# determine handler to call
sub setup_handler {
my ($self) = @_;
# the page handler for each URI of 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 $self->{status}
}
1;
page handler -- controller's method that makes one (or more) pages
sub do_index {
my ($self) = @_;
# page handler must fill $self->{res} hash that process with template
$self->{res}{test} = __PACKAGE__ . 'test';
# and return Apache constant according it's logic
return OK;
}
modeller -- a module that encapsulates application business-logic
package JAF::MyJAF;
use strict;
use DBI;
use base qw( JAF );
sub new {
my ($class, $self) = @_;
$self->{dbh} = DBI->connect(...);
return bless $self, $class;
}
1;
Apache configuration (httpd.conf)
DocumentRoot /examples/site/data
use lib qw(/examples/site/modules);
use Apache::JAF::MyJAF;
SetHandler perl-script
PerlHandler Apache::JAF::MyJAF
PerlSetVar Apache_JAF_Templates /examples/site/templates
# optional or can be specified in Apache::JAF descendant (default value is used in example)
PerlSetVar Apache_JAF_Modules /examples/site/modules/Apache/JAF/MyJAF/pages
# optional or can be specified in Apache::JAF descendant (default value is used in example)
PerlSetVar Apache_JAF_Compiled /tmp
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 hardly simplifies the dynamic development of sites by
designers and programmers. Each programmer works on own part of the
project writing separate controller's parts. Designers have to work only
on visual performance of templates.
Suggested file structure
Suggested site's on-disk structure is:
site
|
+-- data
|
+-- modules
|
+-- templates
*data*
document_root of site. All static files (e.g. JavaScripts, pictures,
CSSs etc) must be placed here
*modules*
Storage place for site modules -- must be in @INC's
*templates*
The place of your site's templates. Framework is designed to
reproduce site's 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's own way:
1 If requested file exists then nothing happens. The handle declines
request with "DECLINE".
2 Otherwise the instance of Apache::JAF's descendant is created and
"setup_handler" method is called. You must override this method and
return determined handler's name. Usually it's the first part of URI
or just "index". Also handlers from "Apache_JAF_Modules" folder is
loaded into package's namespace if "$self->{debug_level}" > 0 or
handlers were not loaded during module compilation.
3 Then goes "site_handler" calling. If you have common tasks for each
handler you can override it. "site_handler" calls your own handler.
It's name is returned by "setup_handler". Usually this
"mini-handler" is *very* simple. It have to be implemented as
package method with "do_**" name. You have to fill
"$self->{res}" hash with result and return Apache constant according
to handler's logic ("OK", "NOT_FOUND", "FORBIDDEN" and so on). The
sample is shown in "SYNOPSIS".
4 If the previous step fulfills correctly, and "$self->{type}"
property is "text/*" then result of processing template returns to
client. If type of result is not like text, one more method is
needed to implement: "on_send_**_data". It must
return binary data to client. This way you may create handlers for
dynamic generation of images, M$ Excel workbooks and any other type
of data.
Apache::JAF methods
setup_handler
This method you must override in your Apache::JAF descendant. You
must return handler's name (that will be called as *do_* method later) from it depending on URI requested by user. You
may set site-wide properties such as *debug_level*, *header* or
*footer*, templates and includes extensions and so on. If handler
name depends on application logic implemented in modeller then you
have to create modeller in this method and store it in *m* property
for later use. The primary *setup_handler* is shown in "SYNOPSIS".
site_handler
You can override this method to provide common tasks for each of
your page-handlers. For example you may create instance of modeller
class, provide some custom authorization/authentication or sessions
handling and so on. You must call "$self>SUPER::site_handler" and
return "$self->{status}" from it.
Apache::JAF properties
r Current "Apache::Request" object.
filter
Using "Apache::Filter" flag.
uri Reference to the array of current URI (splitted by slash). Usually
you need to modify it in "setup_handler" method to determine page's
handler name. Remained array will be passed to the page-handler
method as a list of parameters.
res Hash reference that holds page-handler results.
expand_path
Boolean flag for complex-name-handlers changes '_' to '/' in
handler's name. It provides real-like document tree in the templates
folder.
debug_level
Look at Apache_JAF_Debug in "CONFIGURATION" section.
status
Default handler status is "NOT_FOUND".
type
Default content-type is "text/html". You can call
"$self->download_type()" for set unexisting MIME-type to force
browser download content instead of viewing it.
template_ext, include_ext
Default template extension is ".html". Default include template
extension is ".inc".
default_include
Site-wide include template. Default value is... "default".
header, footer
Site-wide pre- and post-include templates. Defalut values are
"header" and "footer". *Note:*You must undef this properies if you
want create page-template without it. For example for page in pop-up
window ("disable_header", "disable_footer", and
"disable_header_footer" methods).
templates
Path to the templates folder. You may have different sets of
templates for different views of results generated by your
page-handlers.
handler
Result of "setup_handler" method is stored here for later use.
*other properites*
For internal use only.
Implementing handlers
Page handlers are simple. Their methods are with "do_"
name. You have to analyse given parameters, fill out "$self->{res}" hash
with handler results that will be processed with template and return one
of "Apache::Constants". Usually it's "OK", but may be "NOT_FOUND" if
parameters passed to handlers are invalid for some reason.
Look into examples/* folder in the distribution package for some
guidelines.
Templates structure and syntax
Template for a 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 **.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
.
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 simplifies names of page handlers.
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
()
* Template-Toolkit -- template processing system
()
* examples/* -- sample site driven by Apache::JAF
* -- Apache::JAF companion website
AUTHOR
Greg "Grishace" Belenky
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.