CodeIgniter is a Model-View-Controller (MVC)-based application development framework. Essentially this means that each element of an application will be split in to three distinct sections – the model, which deals with data structures; the view, which presents everything to the user; and the controller, which serves to tie the models and views together along with processing other required resources such as user input.
The defining concept behind an MVC architecture is to seperate different aspects of the application whist providing a framework to link them together. For example, since these sections will be the focus of the application’s front-end, our design team can be working away on the view components independently of the rest of the project. This enables the development team to construct the back-end (e.g. model sections) without worrying about conflicting with design changes or, conversely, without preventing the design team from working by forcing them to navigate database issues.
This approach leads to more streamlined coding both front and back. It is easy to define flexible model functions that can be recycled by numerous views. Likewise, views can be created with just presentation in mind and dynamic content can be introduced cleanly and simply by a controller. This structure has the added bonus that models and views are only loaded as they are required which helps keep page load times and resource usage to a minimum.
CodeIgniter provides a well-trimmed solution in other areas too. The first bullet-point in CodeIgniter’s official feature list, entitled “CodeIgniter is right for you if…,” states “You want a framework with a small footprint.” And it certainly delivers. The latest version available for download at the time of writing clocks in at just 3.9 MB uncompressed, positively tiny considering the features we are promised as that list continues. The default installation is also minimal: as simple as copying the files to the web server root. The software doesn’t come bogged down with loads of unnecessary code – in fact, no models are provided whatsoever – just a simple welcome controller and view ensure there exists a default index page. These are easily removed and we’re ready to create our brand new application.