NAME
AxKit::App::TABOO - Object Oriented Publishing Framework for AxKit
INTRODUCTION
There is no code in this file. It may be some day, but for now, it is a placeholder, but one where it is convenient to say what this is, and my design philosophy for it.
AxKit::App::TABOO is a object oriented approach to creating a publishing system on the top of AxKit, the XML Application Server. The two O's thus stands for Object Oriented, AB for AxKit-Based. I don't know what the T stands for yet, suggestions are welcome!
DESIGN PHILOSOPHY
There are three main ideas that forms the basis for TABOO:
- 1. The data should be abstracted to objects so that the AxKit things never have to deal with where and how the data are stored.
- 2. URIs should be sensible and human-readable, reflect what kind of content you will see, and easy to maintain and independent of underlying server code.
- 3. Use providers for all the real content that's served to the user. I like the abstraction Providers give for URIs, and so is an excellent vehicle to achieve the above goal. Also, they provide the cleanest separation of markup from code.
To detail this: I noticed while looking at other people's code, that though it was a lot of interesting code, it would be rather hard to integrate all the interesting parts into a coherent whole. That's why I made the fundamental design choice with TABOO that all data is to be abstracted to objects. Furthermore, everybody has their own way of storing data, and scattered files or different databases didn't seem right to me.
With TABOO, everything that interacts with AxKit just interacts with the Data objects. That means, if you don't want to store things in the PostgreSQL database my Data objects use, you could always subclass it, rewrite the classes or whatever. You would mostly just have to rewrite the load method. It is also the Data object's job to create XML of its own data, save itself, etc.
The intention is to write Data objects for every kind of thing you might want to do. From the start, there will be Slashdot-type stories of varying length, with comments. These are ever-changing in the sense that people can come in an add comments at any time.
It is the intention, however, that TABOO should be a framework where one can add many very different things.
TABOO makes extensive use of Providers. That is mostly because I like the abstraction and direct control of URIs that Providers provide. It makes it easy to create a framework where URIs are sensible and should be easy to maintain for foreseeable future. Also, there is no markup in the code, that's also rather important to make it maintainable.
DESCRIPTION
This is what TABOO contains at this point.:
The base data object, AxKit::App::TABOO::Data and a wealth of subclasses of it, some of which is again subclassed. There are too many to list. They provide an abstraction layer that can manage the data for each of the types. They can load data from a data storage, currently a PostgreSQL data base, and they can write their data as XML, and write it back to the database. There are now also Plural subclasses, built on the AxKit::App::TABOO::Data::Plurals base class. These classes makes it easier to work on more than one of the above objects at a time, something that's often necessary. It also provides some containment of complexity, taking worries off of your head!
Then, there are two AxKit Providers: AxKit::App::TABOO::Provider::News and AxKit::App::TABOO::Provider::NewsList, that makes use of the above subclasses, especially Story and Comment in the first case and the Stories in the second. The first provider creates a page containing an editor-reviewed story and user-submitted comments. The second makes lists of stories. By simply manipulating the URI in easy-to-understand ways, you can load just the story, view the comments, separately, in a list or as a thread, or get simple lists or good overviews of stories.
Currently, it supplies three Taglibs, User, Story and Category. These taglibs provide several tags that you may use interface with the Data objects.
There is quite a lot of XSP and XSLT now that allows you to enter and edit stories and TABOO is nearly useable as a news-site management framework.
Furthermore, there is also some user-management code, including authentication and authorization, to allow adding new users and editing the information of existing users.
It can also format user-entered text with Formatter::HTML::Textile.
It also has some code for i18n, consisting of stylesheets that can take all strings of text from a separate XML file and insert them in the final product. This will make it easy to provide many translations with TABOO, but it needs elaboration, which is next on the TODO list.
CONFIGURATION EXAMPLE
The following is most of the author's AxKit configuration, and should be sufficient to get the code that is currently in TABOO going. It is admittedly a bit messy and could use some reworking. Apart from installing TABOO, you would also need to copy the stuff in htdocs/ directory in the distribution to /var/www or some other DocumentRoot (and adjust the below accordingly). You will also be expected to modify the things that are in the site/ directory of the document root. The things in there are specifically examples, and needs modifying on a per-site basis.
You may also want to get some of the data in the sql/ directory into a database, which can be identified by the DBI_DSN environment variable (see below). Furthermore, TABOO now allows you to set a separate username and password on a databse, and use different databases for different virtual hosts. A combination of DBI_DSN, PGUSER and PGPASSWORD environment variables will achieve this.
# \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
# The below directives are common for all virtual hosts, if you run such
# This stuff is needed for rewriting URIs.
RewriteEngine on
RewriteRule ^/user/([^/]+)$ /user/submit/user.xsp?username=$1
RewriteRule ^/user/submit/$ /user/submit/user.xsp
RewriteRule ^/user/submit/new$ /user/submit/new.xsp
RewriteRule ^/$ /index.xsp
# This may be needed on some setups
DirectoryIndex index.xsp index.xml
# Stuff in the /css/ directory should not be seen by AxKit.
<Location /css/>
SetHandler default-handler
</Location>
# Here starts the the main AxKit-specific things
PerlModule AxKit
SetHandler AxKit
AxHandleDirs On
# Language modules to make XSP and XSLTransformations work
AxAddStyleMap application/x-xsp Apache::AxKit::Language::XSP
AxAddStyleMap text/xsl Apache::AxKit::Language::LibXSLT
AxAddPlugin Apache::AxKit::Plugin::Passthru
AxAddPlugin Apache::AxKit::Plugin::AddXSLParams::Request
PerlSetVar AxAddXSLParamGroups "HTTPHeaders"
# If you want a different language than English, you need to
# translate i18n.en.xml and replace nb with your language
# code. These two directives are optional, you don't need any if you
# want English.
AxAddPlugin Apache::AxKit::Plugin::XSLTParam
PerlAddVar XSLTParam neg.lang '"nb"'
# Authentication
PerlModule Apache::AxKit::Plugin::BasicAuth
AxAddPlugin Apache::AxKit::Plugin::BasicSession
AxAddPlugin Apache::AxKit::Plugin::AddXSLParams::BasicSession
# TABOO XSPs
AxAddXSPTaglib AxKit::App::TABOO::XSP::User
AxAddXSPTaglib AxKit::App::TABOO::XSP::Story
AxAddXSPTaglib AxKit::App::TABOO::XSP::Category
# Other XSPs
AxAddXSPTaglib AxKit::XSP::BasicAuth
AxAddXSPTaglib AxKit::XSP::BasicSession
AxAddXSPTaglib AxKit::XSP::QueryParam
AxAddXSPTaglib AxKit::XSP::Sendmail
# Providers for News, depending somewhat on the paths.
<Location /news/>
PerlHandler AxKit
AxContentProvider AxKit::App::TABOO::Provider::NewsList
PerlSetVar TABOOListDefaultRecords 20
PerlSetVar TABOOListMaxRecords 200
</Location>
<Location /news/submit>
PerlHandler AxKit
AxContentProvider Apache::AxKit::Provider::File
</Location>
<LocationMatch ^/news/(.+)/(.+)/($|comment)>
PerlHandler AxKit
AxContentProvider AxKit::App::TABOO::Provider::News
</LocationMatch>
# ////////////////////////////////
# \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
# These are things that may be sensible to use during development
AxNoCache On
# This parameter can be useful if you suspect you're getting cached
# copies, but it can only be set in the main Apache config.
#MaxRequestsPerChild 1
AxDebugLevel 10
AxDebugTidy On
AxTraceIntermediate /tmp/intermediate
# ////////////////////////////////
# \\\\\\\\\\\\\\\\\\\\\\\\\\\\\
# This section contains stuff that needs to be configured on a virtual host
# basis. It may be an idea to place in it's own file.
# Database connection parameters
PerlSetEnv DBI_DSN dbi:Pg:dbname=taboodemo
PerlSetEnv PGUSER taboodemo
PerlSetEnv PGPASSWORD hk987JKBgui
# Aliases, rather than files have a full filesystem path.
# That's rather evil...
Alias /news/submit /var/www/news/submit.xsp
Alias /login /var/www/login.xsp
# Authentication and authorization stuff
<Location />
AuthType Apache::AxKit::Plugin::BasicAuth
AuthName TABOODemo
</Location>
PerlSetVar TABOODemoURIToken SID
PerlSetVar TABOODemoDataStore DB_File
PerlSetVar TABOODemoArgs "FileName => /tmp/taboodemo-session"
PerlSetVar TABOODemoLoginScript /login.xsp
# /////////////////////////////This should get you the authentication and authorization code you need, set up XSP and the taglibs you need. Note that the order of the Locations matter. The second of them is rather hackish, it doesn't feel good, but it was the way I it working...
TODO
A lot. Because this is a POD, I'm stopping with my lofty visions here (there's more of that in the README). It is still in sort of an alpha state, but Real Soon Now it should be a beta useful enough to put on a test website and have random folks playing with.
Allthough it is not included in the present distro, I have also mostly finished an Article Provider, which is intended to be used for more static content. However, most attention will be given to the News part, because that is the first thing that will give people something to play with.
Finally note that things that are there are not stable! Names may change, parameters may be different, and I may decide to do things differently, depending on how this projects evolves, what new things I learn (this is very much a learning process for me), and what kind of feedback hackers provide.
TABOO also has had some code for a webshop, but since it has fallen behind the rest of the development, it has been removed from the distribution as of 0.08_1. It is however trivial to merge back in, and some of the code is quite OK, and not very hard to update to follow the rest of framework. TABOO will make a great webshop platform...!
SUPPORT
There is now a taboo-dev mailing list that can be subscribed to at http://lists.kjernsmo.net/mailman/listinfo/taboo-dev
BUGS
This release is the first to offer virtual host capacity. It has not been very extensively tested, but in the tests I have done, it works well.
In this release AxKit::App::TABOO::Data::Comment doesn't work. It needs to be reworked to support the new Plurals concept, but that's not at the top of my list for the moment.
There are surely some... Please report any you find through CPAN RT: http://rt.cpan.org/NoAuth/Bugs.html?Dist=AxKit-App-TABOO .
AUTHOR
Kjetil Kjernsmo, <kjetilk@cpan.org>
SEE ALSO
AxKit, AxKit::App::TABOO::Data, AxKit::App::TABOO::Provider::News.
COPYRIGHT AND LICENCE
Copyright (c) 2003-2004 Kjetil Kjernsmo. Some rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.