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MasonX-MiniMVC-0.02
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/ MasonX::MiniMVC

NAME

MasonX::MiniMVC - Very simple MVC framework for HTML::Mason

VERSION

Version 0.02

SYNOPSIS

# in your dhandler
use MasonX::MiniMVC::Dispatcher;
my $dispatcher = MasonX::MiniMVC::Dispatcher->new(\%controllers);
$dispatcher->dispatch($m);

DESCRIPTION

The problem with Mason is that it's just way too tempting to include application logic in your components. It's hard, too, to figure out how to lay out an application. What do you put where? How do you make something that's not a horrible spaghetti tangle?

MasonX::MiniMVC is meant to solve most of these problems for simple applications. It's essentially the simplest thing I could come up with that looks like MVC and stops your Mason components from becoming an unmanageable pile of cruft.

Features

  • A basic directory layout, showing you where to put stuff to keep it under control.

  • Attractive, clean URLs in the form http://example.com/foo/bar/baz. This hides implementation details (*.mhtml filenames) and makes the URLs more search-engine (and human) friendly than http://example.com/foo/bar.mhtml?id=baz.

  • Sample (albeit very slim) controller and model classes are provided.

  • Views are simple Mason components.

Non-features

MasonX::MiniMVC isn't a full-blown MVC framework. If you're looking for something heavyweight, try Catalyst.

MiniMVC also makes some Mason behaviours difficult or impossible. (Most specifically, you just get one top-level autohandler.)

USING MINIMVC

Installation

First, install MasonX::MiniMVC. I'll assume you've done that.

Then cd into the directory where you want your application to be -- probably your webserver's document root -- and run minimvc-install MyApp, replacing "MyApp" with the name of your own application. Since it'll be used as part of Perl module names, it needs to match ^\w+$.

This will create a basic layout for your app. You should see output something like this:

Creating directory structure...
  lib/
  lib/MyApp/
  lib/MyApp/Controller/
  lib/MyApp/Model/
  t/
  view/
  view/sample/
Creating stub/sample files...
  dhandler
  autohandler
  index.mhtml
  lib/MyApp/Dispatcher.pm
  lib/MyApp/Controller/Sample.pm
  lib/MyApp/Model/Sample.pm
  t/controller_sample.t
  t/model_sample.t
  view/default.mhtml
  view/sample/default.mhtml
  .htaccess
  view/.htaccess
  lib/.htaccess
  t/.htaccess

Further setup

  • Set up Apache to handle the directory using HTML::Mason. The provided .htaccess file contains a "SetHandler" directive, but you might need to provide an "AddHandler" in your httpd.conf.

  • Add library paths to the dhandler. Currently there's an empty use lib, but you probably need to add the path to your MiniMVC lib directory, i.e. /some/directory/your-website/lib.

If everything's set up right, you should now be able to point a browser at your application and see a stub/welcome page, with a link to a sample controller-generated page.

APPLICATION DEVELOPMENT WITH MINIMVC

To build your application, the steps will be:

  1. Create model code in lib/MyApp/Model/, using Class::DBI, DBIx::Class, or whatever other kind of ORM you like to use. This will connect to your database and provide an OO representation of the data.

  2. Create a structure for your website, mapping URLs to controllers. Edit MyApp::Dispatcher to create these mappings. Typically you will create a controller for each "noun", eg. users, posts, comments, or whatever is appropriate to your site.

    Here's an example taken from the example "library" application that comes with the MiniMVC distribution:

    package Library::Dispatcher;

use base MasonX::MiniMVC::Dispatcher;

sub new {
    my ($class) = @_;
    my $self = $class->SUPER::new({
        'author'              => 'Library::Controller::Author',
        'book'                => 'Library::Controller::Book',
        'book/recommendation' => 'Library::Controller::Book::Recommendation',
    });
}

1;

  3. Create controller classes for each item you listed in dhandler. Just copy MyApp/Controller/Sample.pm and edit appropriately. Each controller must have at least a default() method, used to show the "top level" page for that part of the site.

    Here's an example default() method:

    sub default {
    my ($self, $m, @args) = @_;
    $m->comp("view/book/default.mhtml");
}

  4. Add methods as you see fit. For instance, you might have a Post.pm and create methods such as new(), edit(), view(), etc. A HTTP request to http://example.com/post/new will call MyApp::Post::new(). A request to http://example.com/post/view/42 will call MyApp::Post::view() with 42 passed in as an argument.

    Here's an example of a method that fetches data using the Model classes, and displays the details:

    sub view {
    my ($self, $m, $id) = @_;
    my $book = Library::Model::Book->fetch($id);
    $m->comp("view/book/view.mhtml", book => $book);
}

  5. As you've seen in the previous steps, the webpage output is done through a view file. These live in view/, and are displayed by calling <$m-comp($view)>> from within the controller code. You can pass args through <$m-comp()>> and they'll be accessible via the Mason <%args> section in the view.

    Using the above example, your book view might look like this:

    <%args>
$book
</%args>

<h1><% $book->title %></h1>
<p>
Author: <% $book->author->name() %>
</p>

A fairly detailed sample application can be found in examples/library/, in the MiniMVC CPAN distribution.

For more examples, see MasonX::MiniMVC::Cookbook.

AUTHOR

Kirrily "Skud" Robert, <skud at cpan.org>

BUGS

The following are unimplemented or simply known not to work. It's early days yet. Comments welcome, though.

autohandlers below the top level

You get one top-level autohandler for your app. You can't have any below that.

404s

I've got it doing a <$m-clear_and_abort(404)>> if it can't find a controller for a URL, but it doesn't work for me under HTML::Mason::CGIHandler. Don't know whether or not it works under full-blown mod_perl Mason, though. Help wanted!

Other

Please report any bugs or feature requests to bug-masonx-minimvc at rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=MasonX-MiniMVC. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

SUPPORT

You can find documentation for this module with the perldoc command.

perldoc MasonX::MiniMVC

You can also look for information at:

ACKNOWLEDGEMENTS

Thanks to:

Paul Fenwick for the autohandler hack to support notes().

COPYRIGHT & LICENSE

Copyright 2007 Kirrily "Skud" Robert, all rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.