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NAME
    XAO::Web - XAO Web Developer, dynamic content building suite

DESCRIPTION
    XAO::Web is a part of XAO open source web services suite. It allows to
    build dynamic web content using data, templates and external input.

    The distinguishing feature of XAO::Web is in its modular design where
    almost every aspect of functionality can be altered and alterations can
    be re-used. No complex code is embedded in the templates which allows to
    upgrade code and templates separately or maintain multiple visual
    representations of the same functionality at the same time.

    Aside from that most interesting features of XAO::Web are:

    *   Perl code is not mixed with templates. Templates can be normal HTML
        files if no processing is required.

    *   A specific site can replace or modify standard XAO::Web objects if
        required by overriding or extending their methods. You do not need
        to re-implement entire object to make a site specific change.

        In case of system object upgrade or bug fix there is no need to
        alter site-specific changes normally.

    *   Site can create any extension objects or embed third-party
        extensions as well.

    *   One server can serve arbitrary number of XAO::Web sites each with
        however extended functionality without creating any conflicts. That
        includes different modifications to the system objects for different
        sites.

    *   Not limited to Web environment, allows to build any dynamic content
        -- content of mail messages or reports for instance.

    *   Works with CGI or mod_perl (mod_perl is recommended for production
        grade sites).

    *   If used in mod_perl mode improves performance by using caching of
        configuration, parsed templates, database handlers and so on.

    *   XAO::Web is by default integrated with XAO::FS (see XAO::FS) as a
        database layer, but this is not a requrement -- if for any reason a
        different database must be used for a site it can be easily and
        gracefully achieved.

    *   Hosting providers can allow their customers to build very complex
        sites without allowing them to execute arbitrary code, by allowing
        to modify only templates.

INSTALLATION
    Download tarball from a CPAN server near you, from the master site
    (<http://xao.com/>) or using links on <http://freshmeat.net/> and then
    install it in the usual way, just say:

      perl Makefile.PL
      make
      make test
      sudo make install

    Saying "install XAO::Web" from the CPAN shell is a good way too:

      perl -MCPAN -eshell
      install XAO::Web

    Using CPAN shell is usually the best way because all dependencies will
    be resolved automatically. If you do manual installation then XAO::Web
    depends on at least the following modules (look into Makefile.PL or just
    watch closely the output of `perl Makefile.PL' for additional
    dependencies):

      XAO::Base
      XAO::FS
      Digest::MD5
      Error
      MIME::Lite
      Test::Unit

    When you run "perl Makefile.PL" you will be asked for XAO::Web test
    database. That database is only used when you do `make test' and it have
    to exist. It does not matter what is inside the database, it will be
    completely wiped out for each test case. Normally the database should be
    the same that you have used for XAO::FS tests and in case of MySQL is
    usually 'test' or 'test_fs'.

    The directory where templates get installed is the same that you gave to
    XAO::Base when you installed it. Normally that directory is
    /usr/local/xao -- we will assume that for the rest of the document.

FIRST-TIME RUNNING AND TESTING
    You are almost there. Now is the time to try it!

    In addition to reading this manual (or instead of reading it if you feel
    too adventurous today) you can look at the generic site setup in the
    misc/samplesite/ directory of the distribution archive. The sample site
    also provides a very useful template to start any project with!

    Configure your Apache server so that it would execute
    /usr/local/xao/handlers/xao-apache.pl when someone types URL like
    http://test.company.com/cgi-bin/xao-apache.pl. Here is an example of a
    virtual host configuration for that (or you can simply sym-link
    xao-apache.pl to your existing cgi-bin directory if you have one):

     <VirtualHost 10.0.0.1:80>
      ServerName   test.company.com
      ScriptAlias  /cgi-bin/ /usr/local/xao/handlers/
     </VirtualHost>

    After you configure and re-start your web-server point your browser at
    http://test.company.com/cgi-bin/xao-apache.pl/mysite/ -- you should be
    able to see the default page template processed by XAO::Web. If you do
    not see it -- you might want to look into apache error log, usually
    there is some additional information there.

    In the URL you used to look at the default page includes 'mysite' as a
    site name. In this case it can be anything you want, nothing depends on
    the name because your site does not yet have any specific templates,
    objects or configuration. We will get back to customizing your site
    later.

    Now let us look into the URL - it does not look good, does it? It
    includes cgi-bin, site name and generally looks ugly, we agree. The way
    to deal with it currently is to use mod_rewrite to hide that into Apache
    configuration. We are working on the real mod_perl module that will not
    require mod_rewrite, you should expect it with the next release of
    XAO::Web.

    Here is how to configure Apache with mod_rewrite in the meantime:

     <VirtualHost 10.0.0.1:80>
      ServerName   test.company.com
      ServerAlias  test.company.com
 
      <Directory /usr/local/xao/handlers>
       Options ExecCGI
       SetHandler cgi-script
      </Directory>

      RewriteEngine on
      RewriteRule   ^/images/(.*)$  \
                    /usr/local/xao/projects/mysite/images/$1  \
                    [L]
      RewriteRule   ^/(.*)$  \
                    /usr/local/xao/handlers/xao-apache.pl/mysite/$1  \
                    [L]
     </VirtualHost>

    That leaves everything in /images/ to be processed by the web server in
    the usual way and maps everything else to XAO::Web handler. Restart
    Apache and try going to just http://test.company.com/ now -- you should
    see the same default page as before.

    And finally, here is an example of mod_perl configuration, you should
    use it for production grade sites. The only difference is in <Directory>
    block.

     <VirtualHost 10.0.0.1:80>
      ServerName   test.company.com
      ServerAlias  test.company.com
 
      <Directory /usr/local/xao/handlers>
       Options ExecCGI
       SetHandler perl-script
       PerlHandler Apache::Registry
       PerlSendHeader Off
      </Directory>

      RewriteEngine on
      RewriteRule   ^/images/(.*)$  \
                    /usr/local/xao/projects/mysite/images/$1  \
                    [L]
      RewriteRule   ^/(.*)$  \
                    /usr/local/xao/handlers/xao-apache.pl/mysite/$1  \
                    [L]
     </VirtualHost>

    That is it, if you got so far your installation of XAO::Web works fine
    and you can move on to actually building a custom web site.

SITE DEVELOPMENT
    Before you go any further it is recommended that you keep cgi-bin
    configuration sample from the examples above as opposed to mod_perl.
    Mod_perl development has its own peculiarities related to caching of
    modules and content and you can get back to that later. Cgi-bin based
    configurations are usually much easier to develop and debug.

    Here is a couple of steps to start the development of a new site.

    1   Choose a name for your site. It have to start with a lowercase
        letter and may contain letters, digits and underscore signs. Let's
        assume you've chosen "mysite" as a name.

    2   Create a sub-directory in /usr/local/xao/projects with the name of
        your site (/usr/local/xao/projects/mysite in our case). This
        directory is the home directory of your site. Everything else below
        is relative to that directory. For simplicity you might want to
        sym-link that directory into your home directory.

    3   Create a sub-directory named 'objects'. Place a configuration file
        called 'Config.pm' inside of it. There is a couple of requrements
        for that file:

        *   Package name have to be 'XAO::DO::Config'.

        *   Usually it defines an init() method that will initialize site
            configuration. In mod_perl environment that method will be
            called only once when the site is initialized for the first
            time. That means that init() is a good place to open connection
            to a database and it is recommended to do that as most of XAO
            modules require database connection to work properly.

        Here is an example of configuration module Config.pm for "mysite"
        site:

         # Configuration for mysite
         #
         package XAO::DO::Config;
         use strict;
         use XAO::Objects;

         # Inheritance from the system Config object
         #
         use base XAO::Objects->load(objname => 'Config', baseobj => 1);

         # Site configuration values. A lot of stuff can be stored here for
         # different modules, base_url is not required, but recommended.
         #
         my %data=(
             base_url        => "http://test.company.com",
             base_url_secure => "http://test.company.com",
         );

         ##
         # Initializing configuration object for our site
         #
         sub init {
             my $self=shift;

             # Creating a database configuration object and embedding it into our
             # configuration, see below for explanation
             #
             my $fsconfig = XAO::Objects->new(
                    objname  => 'FS::Config',
                    odb_args => {
                        dsn       => 'OS:MySQL_DBI:test_fs',
                        user      => 'test',
                        password  => 'test',
                    }
                );
             $self->embed(fs => $fsconfig);

             # Storing configuration into embedded hash
             #
             $self->embedded('hash')->fill(\%data);

             # And finally calling base class' init() method
             #
             $self->SUPER::init();
         }

         1;

        For the more detailed description of `embedding' and initialization
        process in general please refer to XAO::DO::Config.

    4   At that point you should already be able to see your new site in
        your browser. Just point it to
        http://test.company.com/cgi-bin/xao-apache.pl/mysite/ or just
        http://test.company.com/ depending on your Apache configuration.

        But in order to do something useful you normally need to create one
        more directory - 'templates'. That directory will contain all
        templates of your site and unless you use some extended features of
        XAO::Web the layout of files in this directory directly translates
        into URIs.

        Nothing else is used by XAO::Web and usually you would also create
        directories like 'images' or 'static'; put your site to CVS version
        control or make some kind of installation tools for it. It is all up
        to you.

    This is it. Try placing an index.html file into your 'templates'
    directory and go to browser to check how it appears.

AUTHORS
    Copyright (c) 2005 Andrew Maltsev

    Copyright (c) 2001-2004 Andrew Maltsev, XAO Inc.

    <[email protected]> -- http://ejelta.com/xao/

    XAO::Web was created and is maintained by Andrew Maltsev. Creating of
    XAO::Web would not be possible without valuable comments and ideas from
    everybody on our team and especially from Marcos Alves, Bil Drury, Brian
    Despain and Jason Shupe.

SEE ALSO
    Recommended reading: XAO::Web, XAO::Objects, XAO::DO::Config, XAO::FS,
    XAO::DO::FS::Config.