NAME
Apache2::WebApp - Simplified web application framework
SYNOPSIS
This module should not be used directly; it is intended to be run as a mod_perl handler that can be configured as such by adding the following directives to your httpd.conf
PerlRequire /path/to/project/bin/startup.pl
<Perl>
use Apache2::WebApp;
$Apache2::WebApp = Apache2::WebApp->new;
</Perl>
<Location /app>
SetHandler perl-script
PerlHandler $Apache2::WebApp->handler
SetEnv WEBAPP_CONF /path/to/project/conf/webapp.conf
</Location>
DESCRIPTION
The WebApp::Toolkit is a mod_perl web application framework for the Perl programming language. It defines a set of methods, processes, and conventions that help provide a consistent application environment.
The way this package works is actually pretty simple. For every HTTP request, a mod_perl handler is executed that instanciates a new WebApp
controller object. This object is then passed to a dispatch()
method that parses the URI request and maps the result to a public class/method while passing the %controller
as the first argument.
Example:
# URI # Class # Method
/app/project --> maps to --> Project
/app/project/foo --> maps to --> Project::Foo --> or --> Project->foo()
/app/project/foo/bar --> maps to --> Project::Foo::Bar --> or --> Project::Foo->bar()
If the target method does not exist, the distpatch()
will execute the class _global()
and _default()
methods. Below is an example of what a class (.pm) would look like.
Example:
package Project::Foo;
use strict;
use warnings;
# construct as an object (optional)
sub _new {
my $class = shift;
return bless( {}, $class );
}
# this method is executed for every request (optional)
sub _global {
my ( $self, $c ) = @_;
$c->stash('baz','qux');
return $c;
}
# if the target method doesn't exist, this will be executed
sub _default {
my ( $self, $c ) = @_;
$self->_print_result( $c, 'bar' );
}
# _ always denotes a private method (not URI accessible)
sub _print_result {
my ( $self, $c, $output ) = @_;
$c->request->content_type('text/html');
print $output;
exit;
}
# /app/project/foo/bar --> maps to Project::Foo->bar()
sub bar {
my ( $self, $c ) = @_;
$self->_print_result( $c, $c->stash('baz') ); # output 'qux'
}
1;
PREREQUISITES
Apache2::Request
AppConfig
Template::Toolkit
Getopt::Long
Params::Validate
INSTALLATION
From source:
$ tar xfz Apache2-WebApp-Toolkit-0.X.X.tar.gz
$ perl MakeFile.PL PREFIX=~/path/to/custom/dir LIB=~/path/to/custom/lib
$ make
$ make test
$ make install
Perl one liner using CPAN.pm:
$ perl -MCPAN -e 'install Apache2::WebApp'
Use of CPAN.pm in interactive mode:
$ perl -MCPAN -e shell
cpan> install Apache2::WebApp
cpan> quit
Just like the manual installation of Perl modules, the user may need root access during this process to insure write permission is allowed within the installation directory.
GETTING STARTED
HELPER SCRIPTS
Create a new project
$ webapp-project --project_title Project --apache_doc_root /var/www
or
$ webapp-project --config /path/to/conf/webapp.conf
Export project settings to the Unix shell
$ source /path/to/project/.projrc
Create a new class
$ webapp-class --name ClassName
Add a pre-packaged Extra to an existing project
$ webapp-extra --install PackageName
Start your application
$ webapp-kickstart
Standard output
/var/www/project/app <-- A
/var/www/project/app/Project
/var/www/project/app/Project/Base.pm <-- B
/var/www/project/app/Project/Example.pm <-- C
/var/www/project/bin
/var/www/project/bin/startup.pl <-- D
/var/www/project/conf
/var/www/project/conf/htpasswd <-- E
/var/www/project/conf/httpd.conf <-- F
/var/www/project/conf/webapp.conf <-- G
/var/www/project/htdocs <-- H
/var/www/project/templates/example.tt <-- I
/var/www/project/templates/error.tt <-- J
/var/www/project/logs <-- K
/var/www/project/logs/access_log
/var/www/project/logs/errror_log
/var/www/project/tmp <-- L
/var/www/project/tmp/cache
/var/www/project/tmp/cache/templates
/var/www/project/tmp/uploads
A) Application directory. All classes (*.pm) within this directory are precompiled into memory when Apache starts/restarts.
B) Base class that can be included
from other classes. Contains _global()
and _error()
methods that can be inherited using:
Example:
use base qw(
Project::Base
);
C) Basic class.
D) This is executed when the Apache server starts. It's used to reset Perl module search paths in @INC, preload web application classes, precompile constants, etc.
Example:
#!/usr/bin/env perl
$ENV{MOD_PERL} or die "Not running under mod_perl";
use lib '/var/www/project/app';
..
# Modules added here will be URI accessible
__DATA__
Project::Foo
E) Password file used for restricting access to a specified path (see httpd.conf
).
The login information below is currently set-up by default.
User Name admin
Password password
You can change the login password using the htpasswd
command-line script.
$ htpasswd /var/www/project/conf/htpasswd admin
F) Apache server Virtual Host configuration.
G) Application configuration. This file contains your project settings. Due to security reasons, this file should always remain outside the /htdocs directory path.
Example:
[project]
title = Project # must not contain spaces or special characters
author = Your Name Here
email = email@domain.com
version = 0.01
[apache]
doc_root = /var/www/project # path to project directory
domain = www.domain.com # valid domain name
disable_uploads = 0 # allow file uploads
post_max = 5242880 # post max in bytes (example 5MB)
temp_dir = /var/www/project/tmp/uploads
[template]
cache_size = 100 # total files to store in cache
compile_dir = /var/www/project/tmp/cache/templates # path to template cache
include_path = /var/www/project/templates # path to template directory
stat_ttl = 60 # template to HTML build time (in seconds)
H) Website sources. This includes HTML, CSS, Javascript, and images. When setting up FTP access - restrict access to this directory only.
I) Basic template.
J) Application error templates.
K) Apache log directory that contains both access and error logs. Due to security reasons, this directory should always remain outside the /htdocs directory path.
L) Temporary shared space for file processing.
CAVEATS
Since your classes get compiled at Apache start-up, the server must be restarted when any code changes take place. You can do this easily using the webapp-kickstart
script provided with this package.
WARNING
In Perl, variables do not need to be declared and are by default globally scoped. The issue with mod_perl is that global variables can persist between requests. To avoid this problem, you should always have the following line in your code:
use strict;
SEE ALSO
perl(1), mod_perl(2), Apache(2), Apache2::Request, Apache2::RequestRec, Apache2::RequestUtil, Apache2::Connection, Apache2::Upload, Apache2::Const, Apache2::Log
AUTHOR
Marc S. Brooks, <mbrooks@cpan.org> - http://mbrooks.info
COPYRIGHT
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
See http://www.perl.com/perl/misc/Artistic.html
DISCLAIMER OF WARRANTY
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