Pails

Pails is a seriously lightweight MVC framework written in PHP. The overarching vision is that less code is more powerful (and certainly gives rise to fewer bugs). Read more on my blog

Pails is licensed under the GPLv3. If the GPL doesn't work for you, let's talk about your use case. If you need verification that this is free software (for your boss, CTO, etc.), that can also be arranged.

Come talk about pails in #pails on Freenode.

Upgrading a pails app from 0.3.x

The organization of directories has changed a little bit, so that application logic goes in app and public files go in public. The quick solution is to run the following three commands in the root of your pails app:

mkdir app public
mv config controllers helpers initializers models views app/
mv css js images uploads robots.txt .htaccess public

Then you can update the pails composer package and your app will run mostly fine. Due to the change in paths, logic that expects to write to a web-accessible location should be verified/tested.

Quick start

1. Install pails from composer
2. Set up your directories
3. Configure your database
4. Install plugins/packages
5. Add your own layout
6. (Optional) Add your own functionality, using the MVC pattern

Note that there are a set of tools at https://github.com/bparks/pails-tools that will do step 2 (and set up some sample infrastructure) for you, so all you have to do is jump into the directory, run composer install and be up and running.

Install pails

Create a new directory for your project and run

composer require pails

Set up your directories

pails-tools will do this for you, but the typical pails app has the following structure:

my_app
|- app
|  |- config
|  |  |- application.php (database config)
|  |- initializers
|  |  |- _startup.php (initialize any packages)
|  |- controllers
|  |- models
|  |- views
|- public (this is your document root)
|- vendor
|- db (this contains migrations)
|- scripts (any scripts that need the app's environment for e.g. cron)
|- composer.json

Configure your database

MOST sites will need a database to work properly. This is configured in the $CONNECTION_STRINGS array in config/application.php. The format is the same as for php-activerecord:

dbtype://user:password@hostname/dbname

For instance:

mysql://myuser:password@localhost/myappdb

For most sites, this is the only file change that you absolutely have to make.

Install plugins

Pails uses composer. All packages will be autoloaded according to the autoload rules they specify in their composer.json files AUTOMATICALLY.

Add your own layout

Pails ships with a decent look and feel, but it's probably not what you want to stick with on your own web site. The default look and feel is defined in two files, app/views/_layout.php and public/css/custom.css, but only the first is required (the CSS file is simply included to provide some sane defaults). You can replace the _layout.php with your own markup, as long as you include the following line somewhere in the file (this causes pails to render the current page's content):

<?php $this->render(); ?>

Two technical notes:

• You can override views provided by plugins. Simply create a file in your site's views directory with the same name as the view you'd like to override. For instance to override the form displayed by the user/register.php page provided by the pails-auth plugin, I would create a file at app/views/user/register.php with the desired content.
• You can define "partial views" (commonly called "partials") that get included into other views. The markup is the same as for a view, but including them is accompilshed by placing the following code in the view into which you want to include the partial:

  <?php $this->render_partial('path/to/partial', $model) ?>

  The path is relative to the views directory. Omit the .php. The second argument is an optional model for the partial to use. If this argument is omitted, the current view's model is used.

Add your own functionality

pails is potentially infinitely extensible. The framework itself and all of the plugins follow the MVC pattern, which means that the following rules always hold true (they are the ONLY rules of pails, for the most part):

Models go in /models and tend to extend \ActiveRecord\Model. It's not required, but pails works really well with PHP-ActiveRecord, which you can get through composer:

composer require php-activerecord

Controllers go in /controllers with names like StuffController (case matters) and extend \Pails\Controller or \Pails\ResourceController.

Views go in /views, in subfolders named by controller (all lowercase). Thus, a view for the 'index' action of StuffController would be views/stuff/index.php.

Each public method in a Controller class is a valid action.

Plugins

Initially, pails had it its own plugin system, but composer has largely supplanted that. The trend of how to use a composer package with pails is:

1. Install the package from composer
2. If required, initialize the package in initializers/_startup.php or your own initializer (initializers are evaluated alphabetically; _startup MUST be first).
3. Use the use keyword in application logic to include functionality, just like in any other PHP app.

Technical details

Before and after actions

Just like Rails, pails has before and after actions. Right now, they need to be public methods, which are configured as before or after actions with a class-level variable called $before_actions or $after_actions, like so:

$before_actions = array('require_login', 'require_admin');

The referenced functions can't take any arguments.

You can also exclude them from beign applicable to certain actions by making this array associative, like so:

$before_actions = array(
    'require_login',
    'require_admin' => array('except' => array('index')),
    'require_full_moon' => array('only' => array('werewolf', 'howl'))
);

BE WARNED that in a future release, the way to do this properly will be to fiddle with these variables (or preferably to call a method by the same name, which doesn't exist yet) inside the class's __construct() function. This eleminates the problem caused by inheritance of subclasses clobbering before and after actions that are set by superclasses.

Questions?

Send email to bparks@brianparks.me.

Other notes

To generate documentation for the library, run the following command:

phpdoc -d lib -t doc