                     DYNAMIC WEBSITE GENERATOR
----------------------------------------------------------------------

by Darren Duncan <perl@DarrenDuncan.net>

libdwg is a collection of Perl 5 modules that were developed originally to
implement (generate/compile) an unlimited number of unrelated dynamic web-sites
at once, but they can be used for various other purposes as well.  

The intent here was to maximize code reuse such that each instance of a web site
needs very little of its own Perl code to differentiate it from others.  As such,
each "site" consists mostly of a set of hierarchically organized data files, such
as the htmlized text for each page, settings/configuration files that say things
like what questions are asked in forms such as guestbooks, and log files for the
likes of guest books or usage count data.  Modules are designed such that their
behaviour is customized by giving them different data or "preferences", rather
than by changing the values of hardcoded constants.  Everything is designed with
an extensible architecture so third parties can add features to it.  My ultimate
goal is that website owners can update their sites using their web browsers over
a user-friendly interface.

To see living examples of these modules in use, check out my web sites at
"http://www.DarrenDuncan.net" and "http://www.chronology.net".

KEEPING UP TO DATE

These modules are constantly under development.  You should be able to find the
newest versions at my website, "http://www.DarrenDuncan.net", on the page called
"Perl Libraries I Made" (name subject to change).  They can also be found on CPAN
under the author name of "DUNCAND".  

I am inclined to update the copies on my web site more often, but those
intermediate versions are more likely to have been tested less, and the modules
may be updated day by day without increasing the version numbers.  However, the
copies on CPAN are guaranteed to have unique version numbers when the module has
changed.

REQUIREMENTS

All of my modules require Perl 5.004 or newer, even though only some of them need
it, in the interest of consistency.

These third-party modules are required by some of mine.  If they aren't included
in your Perl distribution then you will need to obtain them from CPAN.  The
versions below were the newest as of April of 2000.

HTTP::Headers 1.37
	- by Gisle Aas <gisle@aas.no>
	- in libwww-perl-5.48.tar.gz

Net::SMTP 2.15
	- by Graham Barr <gbarr@pobox.com>
	- in libnet-1.0703.tar.gz

Older versions of these modules may work as well, but I haven't tried using them
so do it at your own frustration.

INSTALLATION

I haven't gotten around to doing makefiles, so you will have to install these the
old fashioned way, by copying.  

Any files that you find in "lib" can go in their corresponding locations in the
"lib" folder that came with your Perl 5 distribution.  Or alternately, put them
anywhere you want, but you will need to have that location added to your include
path by your main program using something like this:

	use lib '/users/me/www_files/lib';

Any existing POD is embedded in the modules themselves, so you will have to look
there to see it, or run a POD extractor on it yourself, or look at the copies on
CPAN that are dutifully extracted and turned to HTML.

MODULE LIST

Here is a quick list of all the modules in the distribution, and what each is
for.  The fully documented ones appear first.

Class::ParamParser 1.0 -- Perl module that provides complex parameter list
parsing for subclass methods.

HTML::TagMaker 1.0 -- HTML::TagMaker -- Perl module that can create any HTML
tags, as well as groups of or just parts of them, and complete html headers or
footers. 

HTML::FormMaker 1.0 -- Perl module that maintains a predefined html input form
definition with which it can generate form html, complete with persistant and
error-checked user input, as well as formatted reports of the user input in html
or plain text.

CGI::HashOfArrays 1.0 -- Perl module that implements a hash whose keys can have
either single or multiple values, and which can process url-encoded data.

CGI::SequentialFile 1.0 -- Perl module that interfaces to a common text file
format which stores records as named and url-escaped key=value pairs.

CGI::EventCountFile 1.01 -- Perl module that interfaces to a tab-delimited text
file for storing date-bounded counts of occurances for multiple events, such as
web page views.

CGI::WPM::Content 0.2 -- Perl module that stores and assembles components of a
new web page, including HTTP headers, and it is returned by all subclasses of
CGI::WPM::Base.

CGI::WPM::Globals 0.2 -- Perl module that is used by all subclasses of
CGI::WPM::Base for managing global program settings, file system and web site
hierarchy contexts, providing environment details, gathering and managing user
input, and providing utilities like sending e-mail.

CGI::WPM::Base 0.2 -- Perl module that defines the API for subclasses, which are
miniature applications called "web page makers", and provides them with a
hierarchical environment that handles details for obtaining program settings,
resolving file system or web site contexts, obtaining user input, and sending new
web pages to the user.

CGI::WPM::Usage 0.2 -- Perl module that is a subclass of CGI::WPM::Base and
tracks site usage details, as well as e-mail backups of usage counts to the site
owner.

CGI::WPM::MultiPage 0.2 -- Perl module that is a subclass of CGI::WPM::Base and
resolves navigation for one level in the web site page hierarchy from a parent
node to its children, encapsulates and returns its childrens' returned web page
components, and can make a navigation bar to child pages.

CGI::WPM::Redirect 0.2 -- Perl module that is a subclass of CGI::WPM::Base and
issues an HTTP redirection header.

CGI::WPM::Static 0.2 -- Perl module that is a subclass of CGI::WPM::Base and
displays a static HTML page.

CGI::WPM::SegTextDoc 0.2 -- Perl module that is a subclass of CGI::WPM::Base and
displays a static text page, which can be in multiple segments.

CGI::WPM::MailForm 0.2 -- Perl module that is a subclass of CGI::WPM::Base and
implements a private e-mail form.

CGI::WPM::GuestBook 0.2 -- Perl module that is a subclass of CGI::WPM::Base and
implements a complete guest book.

HOW TO USE THE MODULES

First of all, it is always a good idea to skim through the POD for any module in
order to learn how to use it.  Any modules at version 1.0 or later have complete
POD, and any modules at version 0.x have incomplete POD.  The exception to this 
is CGI::WPM::Content, which has complete POD despite being at 0.2 (for version 
number parity with all CGI::WPM::* modules).

Now, at this time I don't have an exhaustive tutorial saying how to use these
modules, but I have included two sample "web sites" in the folder called "demos". 
You should be able to install the folder anywhere on your web server, and only
need to modify a single file in each one to make that site operational, and that 
file is in the root of each web site folder, default.pl.

The "website" folder includes a complete site with static pages, email forms, 
guest books, and usage tracking both for page hits, incoming, and outgoing 
visitors.  The "redirector" folder only does usage counting, and issues a 
redirection page; it is intended for sites that have changed addresses so you 
can figure out which other sites still have to fix their links.  In the future 
I will put up more demos, for example, a guestbook-only site.  But you can 
easily derive such from the "website" folder if you desire.  Of course, the 
number of distinct guest books you can have in a single site is unlimited.

The file "default.pl" is the "main program" which calls everything else.  This
file needs to correspond to a web url on your server in order for a web browser
to see it, although it can be run from the command shell.  All of the other files
can be outside the public html directory.  What I do is keep all of the site
files together, and put only a link/alias/shortcut to default.pl in my public web
directory.

Following is a portion of the "default.pl" file:

	use lib '/users/me/www_files/lib';   # this is optional

	require CGI::WPM::Content;
	require CGI::WPM::Globals;
	require CGI::WPM::Base;

	my $webpage;
	my $globals = CGI::WPM::Globals->new();

	if( $globals->user_input_param( 'debugging' ) eq 'on' ) {
		$globals->is_debug( 1 );
		$globals->persistant_user_input_param( 'debugging', 1 );
	}

	$globals->site_root_dir( '/users/me/www_files/demos/website' );
	$globals->system_path_delimiter( '/' );

	$globals->user_vrp( lc( $globals->user_input_param( 
		$globals->vrp_param_name( 'path' ) ) ) );
	$globals->current_user_vrp_level( 1 );
	
	$globals->site_title( 'Sample Website By WPM' );
	$globals->site_owner_name( 'John Sample' );
	$globals->site_owner_email( 'john@sample.net' );
	$globals->site_owner_email_vrp( '/mailme' );  # opt web page within the site

You need to modify your copy of "default.pl" such that the information above is
correct for your server's layout and operating system.  Not all of the function 
calls are required; for example, the last block usually just applies to e-mail.

All else I can suggest to figure things out is examine the files in the "demo"
folder side-by-side with exploring the generated web site in your browser, and
see what affect changing certain things has.  The demo site makes use of all the
distribution modules in some way or other, but a real site doesn't have to.

FEATURES

When all of the modules in this set are used together, these are some of the
features that programs using them can have:

* Fully compliant with the HTML 4.0 standard and Cascading Style Sheets.

* Single or multiple pages in each site, which can be organized hierarchically. 
At each hierarchy level, a naviagation bar can be automatically provided or left
out.

* Display static pages read from an ordinary HTML document; the source can be a
complete HTML document or only that which would go between the 'body' tags.

* Provide html forms for sending private e-mails to the site owner, with a
visitor-defined option for the sender getting their own copy.  The user input is
automatically error-checked for completeness and shows the visitor what they did
wrong if not.  The mail is sent using SMTP directly, so it works on systems that
don't have 'sendmail'.

* Provide guest books with all the features of private mail forms and more. The
number and field type of questions is unlimited, and the input validity checking
is customizable.  Guest book entries are displayed with the sender's name and
time of submission, but their e-mail address is hidden.

* Display plain text documents with their formatting intact (using 'pre' tags)
along with relevant details like title, author, version and dates created or
modified.  Long documents can optionally be segmented and displayed as a series
of parts, which can be navigated with an automatically provided navigation bar.

* Automatically redirect visitors to an external url from an internal one.

* Usage of the site can be counted, and for each usage event are the count of
total occurances, count of today's occurances, date of first occurance, and date
of last occurance.  Usage details that can be counted include: which site pages
were viewed, which external urls we redirect visitors to, which external urls
have a link to us (that were used), and miscellaneous environment details like
GET vs POST vs HEAD requests.  The details are counted independently of each
other.  Usage information can be compiled and e-mailed to the owner once per day
for backup/report purposes.  Referring urls are smartly subgrouped such that
search engines and normal web sites appear separately, and also the search
keywords are in their own group so it is easy to see at a glance what kinds of
searches led visitors to you.

* Search and replace of content at site visitation time so that repeating and/or
complicated data in static source files can be substituted by other static or
dynamic content which changes over time, such as a hyperlink to e-mail the owner
(addresses change), or directory url holding graphics.

* Generated sites are usable on all visitor computing platforms, no matter what
web browsers they have, even if text-only.

* The site can be seamlessly moved from one web or physical address or computer
platform to another, and nothing will break. I have tested it on UNIX, Linux,
Windows, Macintosh successfully. All platform-specific details are confined to a
single site-settings file, which is quoted above.  Most site details are in other
files, which are platform agnostic.  The site can be invoked from a command
prompt for testing if desired.

* The site can be invoked using an optional query parameter that will turn
debugging on.  The site-program will then know that it is the owner viewing the
site, and can do some things differently in accordance. Currently the only
difference is that a separate set of usage logs are kept, so normal hit counters
aren't racked up when testing something.

* The site's support files can all be stored outside the 'public_html' directory,
so attempts to view them directly will fail (no corresponding web url).  Only the
main shell (or link to it) must be in the 'public_html'.

* Hooks are provided so that future versions of this program will let the site
owner edit the site's content using its own web forms.  That is, remote
administration. Currently, the only way to edit a site's content is to use
ftp/telnet to directly change the site support files. For security purposes,
admin_mode can only be invoked by calling a separate module method, which would
likely be in a separate shell/main program.

* The progam modules are designed in an elegant and extensible format, so
additional "plug-in" modules can be made to provide additonal functionality, such
as a threaded discussion board, or database-access pages, without changing the
other program code.  In the future, it should be easy to add features for content
searching and reporting, internal site spidering (more efficient), and more.

* The modules have extensive error checking and graceful exit routines built-in
so that nothing the site visitor does should make the program crash (although the
Perl interpreter itself or the web server is a different story).  If the program
did crash, then the visitor would get a nondescript "server error" message
without any idea why it happened.  Likewise, many checks are in place to account
for problems introduced by the site programmer themselves, such as improperly
made settings, nonexistant files, or non-compiling plug-in modules.  For better
or worse, the program currently gives details on exactly what went wrong, so that
the owner who is testing it has an easy time fixing it.

* The modules are designed to be compatible with mod_perl, but I haven't tested this possibility yet; I will soon.  I say this because I avoid using global variables and I pass all subroutine parameters, and I don't use "main" at all.  All file-scoped variables are initialized at compile time (of that file), but some keys in my hashes may not be (they're optional), so hopefully that doesn't cause problems with the "initialize everything" rule.

SUPPORT

Currently I don't have any support arranged with other people, lists, newsgroups, or otherwise.  Feel free to ask me if you can't figure things out on your own.  However, I am very busy so please ask only if you have a genuine interest in the modules and are considering using them.  This policy should change later as I gain more free time.

AUTHOR

Copyright (c) 1999-2000, Darren R. Duncan. All rights reserved. These modules are
free software; you can redistribute them and/or modify them under the same terms
as Perl itself.  However, I do request that their copyright information remains
attached to the files.  If you modify this module and redistribute a changed
version then please attach a note listing the modifications.

I am always interested in knowing how my work helps others, so if you put this
module to use in any of your own code then please send me the URL.  Also, if you
make modifications to the module because it doesn't work the way you need, please
send me a copy so that I can roll desirable changes into the main release.

Address comments, suggestions, and bug reports to B<perl@DarrenDuncan.net>.

Share and Enjoy!
