NAME

Apache::PageKit - Application framework using mod_perl and HTML::Template

SYNOPSIS

Perl Module that inherits from Apache::PageKit:

  package MyPageKit;

  use Apache::PageKit;

  use vars qw(@ISA);
  @ISA = qw(Apache::PageKit);

  use Apache::Constants qw(OK REDIRECT DECLINED);

  sub handler {
    $dbh = DBI->connect("DBI:mysql:db","user","passwd");
    my $pk = __PACKAGE__->new(
			      dbh => $dbh,
			      session_lock_class => 'MySQL',
			      session_store_class => 'MySQL',
			      session_args => {
					       Handle => $dbh,
					       LockHandle => $dbh,
					      },
			     );

    my $status_code = $pk->prepare_page;
    return $status_code unless $status_code eq OK;

    $pk->prepare_view;

    $pk->print_view;

    return $status_code;
  }

  sub auth_credential {
    my ($pk, @credentials) = @_;

    # create a session key from @credentials
    # your code here.........

    return $ses_key;
  }

  sub auth_session_key {
    my ($pk, $ses_key) = @_;

    # check whether $ses_key is valid, if so return user id in $user_id
    # your code here.........

    return $ok ? $user_id : undef;
  }

In httpd.conf

SetHandler perl-script
PerlSetVar PKIT_ROOT /path/to/pagekit/files

# this comes before PerlHandler so that PKIT_ROOT/Module gets added to @INC
PerlModule Apache::PageKit 
PerlHandler +MyPageKit

DESCRIPTION

PageKit is an mod_perl based application framework that uses HTML::Template and XML to separate code, design, and content. Includes session management, authentication, form validation, co-branding, and a content management system.

Its goal is to solve all the common problems of web programming, and to make the creation and maintenance of dynamic web sites fast, easy and enjoyable.

You have to write a module that inherits from Apache::PageKit and provides a handler for the PerlHandler request phase. If you wish to support authentication, it must include the two methods auth_credential and auth_session_key.

For more information, visit http://www.pagekit.org/ or http://sourceforge.net/projects/pagekit/

OBJECTS

Each $pk object contains the following objects:

$pk->{apr}: An Apache::Request object. This gets the request parameters and can also be used to set the default values in HTML form when fill_in_form is set.
$pk->{config}: An Apache::PageKit::Config object, which loads and accesses global, server and page attributes.
$pk->{content}: An Apache::PageKit::Content object, which accesses the content stored in the XML files.
$pk->{model}: An Apache::PageKit::Model object, currently used for validating HTML forms.
$pk->{session}: A reference to a hash tied to Apache::PageKit::Session.
$pk->{view}: An Apache::PageKit::View object, which interfaces with the HTML::Template templates.

Features

Model/View/Content/Controller approach to design

The Model is the user provided classes, which encapsulate the business logic behind the web site.

The View is a set of HTML::Template templates. Apache::PageKit::View acts as a bridge between the templates and the controller.

The Content is stored in XML files in the Content/xml directory. You may also store the content in the HTML::Template templates, if you don't need to seperate the View from the Content.

The Controller is a subclass of Apache::PageKit, which reads the client request, accesses the back end, and uses Apache::PageKit::View to fill in the data needed by the templates.

Seperation of Perl from HTML

By using HTML::Template, this application enforces an important divide - design and programming. Designers can edit HTML without having to deal with any Perl, while programmers can edit the Perl code with having to deal with any HTML.

Seperation of Content from Design with XML

By using the <CONTENT_VAR> and <CONTENT_LOOP> elements, you can autofill the corresponding <CONTENT_VAR> and <CONTENT_LOOP> tags in the template.

This is an easy way of using XML with HTML::Template that doesn't require the use of stylesheets.

Page based attributes

The attributes of each Page are stored in the Config/Config.xml file. This makes it easy to change Pages across the site. Apache::PageKit::Config provides a wrapper around this XML file.

For example, to require a login for a page, all you have to do is change the require_login attribute of the XML <PAGE> tag to yes, instead of modifying the Perl code or moving the script to a protected directory.

Automatic Dispatching of URIs

Apache::PageKit translates $r->uri into a class and method in the user provided classes. In the example in the synopsis, the URI /account/update will map to MyPageKit::PageCode::account->page_update.

Easy error handling.

Both warnings and fatal errors can be displayed on the screen for easy debugging in a development environment, or e-mailed to the site adminstrator in a production environment, as specified in the Apache ServerAdmin configuration directive.

You have to require Apache::PageKit::Error to turn on error handling.

Session Management

Provides easy access to a hash tied to Apache::PageKit::Session.

Authentication

Restricts access to pages based on the require_login attribute. If require_login is set to recent, then PageKit requires that session is currently active in the last recent_login_timeout seconds.

Form Validation

Uses HTML::FormValidator to provide easy form validation. Highlights fields in red that user filled incorrectly by using the <PKIT_ERRORFONT NAME="FIELD_NAME"> </PKIT_ERRORFONT> tag. To use, pass an input profile to the validate method of Apache::PageKit::Model from your perl code option.

Sticky HTML Forms

Uses HTML::FillInForm to implement Sticky CGI Forms.

One useful application is after a user submits an HTML form without filling out a required field. PageKit will display the HTML form with all the form elements containing the submitted info.

Multiple Views/Co-branding

Any page can have multiple views, by using the pkit_view request parameter. One example is Printable pages. Another is having the same web site branded differently for different companies.

Components

PageKit can easily share HTML templates across multiple pages using components. In addition, you may specify Perl code that gets called every time a component is used by adding a component_component_id method to the Perl module specified by component_dispatch_prefix.

Language Localization

You may specify language properties by the xml:lang attribute for <CONTENT_VAR> and <CONTENT_LOOP> tags in the XML content files.

The language displayed is based on the user's preference, defaulting to the browser settings.

METHODS

The following methods are available to the user as Apache::PageKit API.

new

Constructor object.

  $pk = __PACKAGE__->new(
			 dbh => $dbh,
			 session_lock_manager => 'MySQL',
			 session_object_store => 'MySQL',
			 session_args => {
					  Handle => $dbh,
					  LockHandle => $dbh,
					 },
			);

Each option is accessible from the object's hash. For example $dbh is acessible from $pk->{dbh}.

prepare_page

This executes all of the back-end business logic need for preparing the page, including executing the page and component code.

prepare_view

This fills in the view template with all of the data from the back-end

print_view

Called as a last step to output filled in view template.

message

Displays a special message to the user. The message can displayed using the <PKIT_LOOP NAME="MESSAGE"> </PKIT_LOOP> code.

To add a message,

$pk->message("Your listing has been deleted.");

To add an error message (typically highlighted in red), use

$pk->message("You did not fill out the required fields.",
             is_error => 1);

redirect

Redirects to the specified URL. Should be called from the back-end code specified by page_dispatch_prefix.

package MyPageKit::PageCode;

sub page_id {
  my $pk = shift;

  $pk->redirect("http://yourdomain.com/new_page");
}

continue

Continues onto another PageKit page. Should be called from the back-end code as specified by page_dispatch_prefix.

$pk->continue($new_page_id, $no_code);

$page_id specifies the new page. If $no_code is set to 1, then method doesn't execute the associated page code. $no_code defaults to 0.

auth_credential

You must define the method yourself in your subclass of Apache::PageKit.

Verify the user-supplied credentials and return a session key. The session key can be any string - often you'll use the user ID and a MD5 hash of a a secret key, user ID, password.

auth_session_key

You must define the method yourself in your subclass of Apache::PageKit.

Verify the session key (previously generated by auth_credential) and return the user ID. This user ID will be fed to $r->connection->user().

MARKUP TAGS

Most tags get "compiled" into <TMPL_VAR>, <TMPL_LOOP>, <TMPL_IF>, <TMPL_UNLESS>, and <TMPL_ELSE> tags. See the HTML::Template manpage for description of these tags.

<PKIT_COMPONENT NAME="component_id">

Calls the component code (if applicable) and includes the template for the component component_id.

<PKIT_ERRORFONT NAME="FIELD_NAME"> </PKIT_ERRORFONT>

This tag highlights fields in red that Apache::PageKit::Model reported as being filled in incorrectly.

<PKIT_LOOP NAME="BREAD_CRUMB"> </PKIT_LOOP>

Displays a bread crumb trail (a Yahoo-like horizontal navigation that looks like Top > Category > Sub Category > Current Page ) for pages that have bread_crumb set to yes.

Template should contain code that looks like

<PKIT_LOOP NAME="BREAD_CRUMB">
  <PKIT_UNLESS NAME="__LAST__"><a href="/<tmpl_var name="page">"></PKIT_UNLESS><PKIT_VAR NAME="NAME"><PKIT_UNLESS NAME="__LAST__"></a></PKIT_UNLESS>
  <PKIT_UNLESS NAME="__LAST__"> &gt; </PKIT_UNLESS>
</PKIT_LOOP>

<PKIT_IF NAME="INTERNET_EXPLORER"> </PKIT_IF>

Set to 1 if User-Agent is a Microsoft Internet Explorer browser.

<PKIT_VAR NAME="LOGINOUT_LINK">

If user is logged in, provides link to log out. If user is not logged in, provides link to log in.

<PKIT_LOOP NAME="MESSAGE"> </PKIT_LOOP>

Displays messages passed to $pk->message method.

Template should contain something that looks like

<PKIT_LOOP NAME="MESSAGE">
   <PKIT_IF NAME="IS_ERROR"><font color="#ff0000"></PKIT_IF>
   <PKIT_VAR NAME="MESSAGE">
   <PKIT_IF NAME="IS_ERROR"></font></PKIT_IF>
   <p>
</PKIT_LOOP>

This code will display error message seperated by the HTML <p> tag, highlighting error messages in red.

<PKIT_IF NAME="NETSCAPE"> </PKIT_IF>

Set to 1 if User-Agent is a Netscape browser.

<PKIT_VAR NAME="SELFURL">

The URL of the current page, including CGI parameters. Appends a '&' or '?' at the end to allow additionial parameters.

<PKIT_VAR NAME="USER">

user_id of authenticated user, equal to $r->connection->user, unless overridden.

<PKIT_IF NAME="VIEW:view"> </PKIT_IF>

Set to true if pkit_view request parameter equals view.

OPTIONS

Constructor Arguments

These arguments are global in the sense that they apply over all pages and servers.

session_args: Reference to an hash containing options for the session_lock_class and session_store_class.
session_lock_class: The lock manager class that should be used for Apache::PageKit::Session session handling.
session_store_class: The object store class that should be used for Apache::PageKit::Session session handling.

Other configuration variables

Global, server and page configuration variables are described in the Apache::PageKit::Config perldoc page.

REQUEST PARAMETERS

These are parameters that are specified in GET requests and POST requests where Content-type is one of application/x-www-form-urlencoded or multipart/form-data.

pkit_credential_#: Login data, typically userid/login/email (pkit_credential_0) and password (pkit_credential_1).
pkit_done: The page to return to after the user has finished logging in or creating a new account.
pkit_lang: Sets the user's preferred language, using a ISO 639 identifier.
pkit_login_page: This parameter is used to specify the page that user attempted to login from. If the login fails, this page is redisplayed.
pkit_remember: If set to true upon login, will save user's cookie so that they are still logged in next time they restart their browser.
pkit_view: Used to implement multiple views/co-branding. For example, if set to print, will search for templates in the View/print directory before using templates in the View/Default directory, and sets the pkit_view:print parameter in the view to true.

VERSION

This document describes Apache::PageKit module version 0.90

NOTES

Requires mod_perl, XML::Parser, HTML::Clean, HTML::FillInForm, HTML::FormValidator, and HTML::Template.

I wrote these modules because I needed an application framework that was based on mod_perl and seperated HTML from Perl. HTML::Embperl, Apache::ASP and HTML::Mason are frameworks that work with mod_perl, but embed Perl code in HTML. The development was inspired in part by Webmacro, which is an open-source Java servlet framework that seperates Code from HTML.

The goal is of these modules is to develop a framework that provides most of the functionality that is common across dynamic web sites, including session management, authorization, form validation, component design, error handling, and content management.

If you have used (or are considering using) these modules to build a web site, please drop me a line with the URL of your web site. My e-mail is tj@anidea.com. Thanks!

BUGS

This framework is in alpha stage. The interface may change in later releases.

Please submit any bug reports, comments, or suggestions to tjmather@anidea.com, or join the Apache::PageKit mailing list at http://lists.sourceforge.net/mailman/listinfo/pagekit-users

TODO

Associate sessions with authenticated user ID.

Add web based editing tools allowing authorized user to edit View, Content and Configuration files

Add more tests to the test suite.

Make content sharable across pages.

Move Apache::PageKit::Error to seperate distribtuion.

Add <PKIT_SELFURL_WITHOUT:param1:param2> tag.

AUTHOR

T.J. Mather (tjmather@anidea.com)

COPYRIGHT

LICENSE

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the Ricoh Source Code Public License for more details.

You can redistribute this module and/or modify it only under the terms of the Ricoh Source Code Public License.

You should have received a copy of the Ricoh Source Code Public License along with this program; if not, obtain one at http://www.pagekit.org/license

To install Apache::PageKit, copy and paste the appropriate command in to your terminal.

cpanm

cpanm Apache::PageKit

CPAN shell

perl -MCPAN -e shell
install Apache::PageKit

For more information on module installation, please visit the detailed CPAN module installation guide.

	Global
`s`	Focus search bar
`?`	Bring up this help dialog

	GitHub
`g` `p`	Go to pull requests
`g` `i`	go to github issues (only if github is preferred repository)

	POD
`g` `a`	Go to author
`g` `c`	Go to changes
`g` `i`	Go to issues
`g` `d`	Go to dist
`g` `r`	Go to repository/SCM
`g` `s`	Go to source
`g` `b`	Go to file browse

	Search terms
module: (e.g. module:Plugin)
distribution: (e.g. distribution:Dancer auth)
author: (e.g. author:SONGMU Redis)
version: (e.g. version:1.00)