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NLB Handbook

NLB is a PHP application framework that follows the MVC pattern and is built from the ground up for performance. This is the NLB Handbook which will guide you in your quest to become a master of all things NLB.

Installation

Requirements

• Linux/FreeBSD (no Windows support at this time)
• PHP 5.3 or higher with PDO mysql driver working
• Apache2 with mod_rewrite enabled
• MySQL 5.0+
• YUI Compressor 2.4.7+ installed on your server download link

Installing NLB is not too difficult. Here are the steps to install:

• Download the NLB code and put it on your server somewhere.
• Create a new VirtualHost that points to the www folder.
• Copy the sites/default/config/example.config.inc.php file to sites/default/config/config.inc.php.
• Edit the new config.inc.php file to have the necessary settings for your application.
• Visit http://<yoursite.com>/install.php changing <yoursite.com> to your actual domain name.
• Follow the on-screen instructions to install NLB.
• Make sure the following directories exist (relative to the NLB root folder) and that they are writable by apache:
  • logs
  • www/combined-assets
  • smarty/templates_c
  • smarty/cache

Routes

In NLB, routes are used to create a mapping between a particular path and a controller that should handle that path. Access restrictions can also be added to a route preventing certain users from accessing certain areas of your application. NLB has a list of it's own routes in the config/nlb_routes.inc.php file. To define your own routes you must use the sites/default/config/routes.inc.php file. The routes in sites/default/config/routes.inc.php will override routes defined in config/nlb_routes.inc.php. This allows you to change NLB's default behavior if desired. Below is a simple routes.inc.php file defining a route that would be used for a simple blog post listing:

<?php
$routes = array(
    'blog' => array(
        'handler' => 'blog.php?action=list',
        'access' => array('anonymous user'),
    ),
);

Given that defined route, NLB will route requests to /blog to the blog.php controller and will set $_GET['action'] to 'list'. It's important to note that any query string parameters in your handler definition will be automatically merged with the $_GET array, overwriting any existing keys in the $_GET array. Also, in keeping with PHP's standards, the query string parameters in your handler definition will also be automatically merged with the $_REQUEST array for consistency. Controllers in the handlers directory can be organized into subdirectories if desired. This helps to keep the code for larger sites more manageable.

Dynamic Routes

When defining a route, it is possible to use a wildcard in your path definition. Using a wildcard allows you to map multiple similar paths to a single controller. The value of the wildcard can then be passed to the controller. Wildcards can be alphanumeric and may also contain underscores. There can be multiple wildcards in a path definition. Take a look at this route definition which would be used for viewing specific blog posts:

<?php
$routes = array(
    'blog/view-%post_id' => array(
        'handler' => 'blog.php?action=viewpost&id=%post_id',
        'access' => array('anonymous user'),
    ),
);

Using this defined route, NLB will route requests to paths like /blog/view-3 and /blog/view-7 to the blog.php controller and will set $_GET['action'] to 'viewpost' and $_GET['id'] to '3' or '7' respectively.

Templates

NLB uses the Smarty template system. Currently, a bundled version of Smarty 3.x is included with NLB for your convenience.

When rendering templates, NLB has been configured to first search for templates in the sites/default/themes/<your_theme>/ directory. If the template does not exist there, the smarty/nlb_templates directory is searched. With this configuration, you can override any default template that comes with NLB by providing your own version of the template. Just make sure the file has the exact same name as the NLB default template.

Multi-Site Configuration

NLB has a feature that allows you to run multiple websites from the same NLB core. The way this is done is by copying the sites/default directory to sites/<your_site> where <your_site> is the hostname for the site you are configuring as a multi-site. NLB will try to match the hostname in the request to the name of one of the directories in the sites directory. If a match is found, the config file for that directory will be used instead of the one in the sites/default/config directory. Also, the themes and request handlers in that directory will be used instead of the ones in sites/default. If no match is found, NLB defaults to using the sites/default directory. NLB will also try to do partial matches against the hostname to try and find a matching multi-site directory. Below are some examples of how NLB matches hostnames to directories in sites. Given the hostname www.example.com, NLB will look for the following directories in sites (in this order):

1. www.example.com
2. example.com
3. www.example
4. example
5. default

Given the hostname example.com, NLB will look for the following directories in sites (in this order):

1. example.com
2. example
3. com
4. default