Gantry::Docs::QuickStart(3)

Name
Gantry::Docs::QuickStart - Getting your first Gantry app up and running

Off and running
The easiest way to build a Gantry app is with bigtop:

    bigtop -n AppName 'book(title,pages:int4)<->author(name)'

Choose a suitable application name and list the tables you've already thought of, including their columns. When you think of more tables and columns later, they will be easy to add. To learn more about this kickstart syntax see Bigtop::ScriptHelp::Style::Kickstart.

If you have sqlite in your path, bigtop will build a database for you. Then all you need to do is change to the directory it made for your app and start the stand alone server.

    cd AppName
    ./app.server

If you don't use sqlite (or bigtop could not find it in your path), change to the directory bigtop built for you. Create a database called app.db with your database engine, populate the database, and start the app.server. With Postgres that looks like this:

    cd AppName
    createdb app.db -U postgres
    psql app.db -U regular_user < docs/schema.postgres
    ./app.server -d Pg -u regular_user -p password

For MySQL, try this instead:

    cd AppName
    msyqladmin create app_db -u root -p
    mysql -u root -p app_db < docs/schema.mysql
    ./app.server -d=mysql --u=regular_user -p='secret' -n=app_db

Then the app is running, you can view it by pointing your browser to any of the URLs app.server printed on startup.

A Simple Greeting
This section is for those who prefer a less magical experience.

All you need for a gantry app is a module which uses Gantry and has a method called do_something (usually do_main is a good first choice):

    package HiWorld;
    use strict; use warnings;

    use base 'Gantry';

    sub do_main {
        my $self = shift;

        return "Hello, Rob";
    }

    1;

I'll store this module in /home/myhome/lib/HiWorld.pm. I'll need to set that lib path with a use lib below.

Stand Alone Server Deployment
If you have HTTP::Server::Simple installed, you may choose to deploy your application through it. This is useful for kick starting development. See below for more permanent means of deployment.

A stand alone Gantry application is an executable script which leverages Gantry::Server (which in turn uses HTTP::Server::Simple). This one is enough for our small demo:

    #!/usr/bin/perl
    use strict;

    use Gantry::Server;

    use lib '/home/myhome/lib';

    use HiWorld qw{ -Engine=CGI -TemplateEngine=Default };

    my $cgi = Gantry::Engine::CGI->new();

    $cgi->add_location( '/', 'HiWorld' );

    my $port   = shift || 8080;
    my $server = Gantry::Server->new( $port );

    $server->set_engine_object( $cgi );
    $server->run();

If you used Bigtop, as in the first section of this document, it made "app.server" which is similar to this one.

CGI Deployment
To deploy using CGI, create the following script in a servable cgi-bin directory (remember to make sure it is executable):

    #!/usr/bin/perl
    use strict;

    use CGI::Carp qw( fatalsToBrowser);

    use lib '/home/myhome/lib';

    use HiWorld qw{ -Engine=CGI -TemplateEngine=Default };

    my $cgi = Gantry::Engine::CGI->new();

    $cgi->add_location( '/', 'HiWorld' );

    $cgi->dispatch();

Then point your browser to the script.

If you used Bigtop to generate the application, as shown in the first section above, it made "app.cgi" for you. You can deploy to CGI by copying that file into your web server's "cgi-bin" directory, if you also:

install the app
    The HiRob.pm module must be installed somewhere in the @INC path, or you must add a "use lib" statement in your CGI script which includes the directry where the module lives.

set permissions correctly
    First, the web server must be able to read the build directory and its sub directories. (If you have an sqlite database, you must make both the database and the build directory writable by the web server.)

beware of selinux
    Tools like selinux exist to keep people from accessing things. As such, they will probably block users from seeing things in your build directory via a web server. Either disable it, or move things to appropriate places it allows the web server to access.

See "What is Gantry::Conf" and "How do I use Gantry::Conf under CGI/FastCGI" in Gantry::Docs::FAQ for information on switching the CGI script to a different database.

mod_perl Deployment
To use mod_perl, you must have permission to modify the httpd.conf for your web server and to restart it. Here is the virtual host I created for the greeting application:

    <VirtualHost hiworld.devel.example.com>

        ServerName   hiworld.devel.example.com
        DocumentRoot /home/myhome/html/play
        CustomLog    /home/myhome/logs/combined.log combined
        ErrorLog     /home/myhome/logs/hiworld.err

        Include /home/myhome/html/play/hiworld.conf

    </VirtualHost>

This throws the real config work to hiworld.conf. Mine assumes mod_perl 1.3. Here it is:

    <Perl>
        #!/usr/bin/perl

        use lib '/home/pcrow/srcgantry/play';

        use HiWorld qw{ -Engine=MP13 -TemplateEngine=Default };
    </Perl>

    <Location /hello>
        SetHandler  perl-script
        PerlHandler HiWorld
    </Location>

After restarting the server, I can point my browser to

    http://hiworld.devel.example.com/hello

to see the greeting.

If you are using mod_perl 2, simply change the use statement to:

        use HiWorld qw{ -Engine=MP20 -TemplateEngine=Default };

(i.e. replace MP13 with MP20)

Note that if other Gantry apps are running in the same server instance, they may fight over which template engine to use. Generally, the first app to put in a use statement for its base module chooses the template engine. We don't mind this since we always use TT. Even after you have chosen TT, you can turn it off by adding statements like these to the top of your do_* method.

    $self->content_type( 'text/xml' );
    $self->template_disable( 1 );

What To Do Now
Once you have your first app running, as shown above, you are ready to move on in the following sequence of documents:

1.  Gantry::Docs::Tutorial

2.  Bigtop::Docs::Tutorial

After those, you probably want Gantry::Docs::FAQ, Gantry::Docs::Cookbook, or Bigtop::Docs::Cookbook.

Author
Phil Crow <crow.phil@gmail.com>

Copyright and License
Copyright (c) 2006-7, Phil Crow.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.6 or, at your option, any later version of Perl 5 you may have available.