Drupal Architecture

Although Drupal performs all the operations of a 'content management system', it might more accurately be described as a 'content management framework' because unlike a typical commercial application, it is primarily directed towards customisation and configurability. Drupal breaks down the boundary between specialised and abstracted by providing a toolkit of pre-designed parts and features that can be employed in their default arrangements or can be significantly rejigged to suit shifting requirements. By breaking the application down to its components, Drupal allows powerful websites to be built with unmatched flexibility.

Drupal's content management system is structured in levels. At the heart of the system is the data pool, composed of nodes that are organised by managing and editing navigation menus. A node is a cluster of related data that contains structured information applying to specific segments of content within the website. Collating all data in a single 'pool' ensures all content shares the same foundations and can be combined and reordered, and searched and compared, which opens up powerful and inventive possibilities. Nodes are stored in tables in Drupal's database.

Modules operate on the information contained by the nodes to improves a website's functionality and increase its capabilities. Themes alter the overall look and feel of a website. The official Drupal installation comes with a range of modules and themes that are easily extensible by the download of user-created contributions to the development pool. The rapidly expanding repository of module contributions presents hundreds of distinct alternatives for customisation.

Drupal's next layer incorporates menus and blocks. Blocks supply a module's output, and can be configured to vary the manner in which they display this output, in response (if required) to certain pages and users.

User permissions allow different roles to be assigned varying levels of access to information and editing capacity. Drupal's settings can be configured to restrict permission to certain areas for certain users.

The site template provides the surface layer, which is composed predominantly of XHTML and CSS (Cascading Style Sheets). Incorporated in every template are executive functions that can be used to countermand standard module functions, allowing precise direction of how the modules create their markup when it comes to output.

Drupal's architecture means that the standardisation of its operations facilitates and encourages customisation of site functions and removes many of the obstacles that frequently block the effective adaptation of commercial software. Nonetheless, this enhanced flexibility does require an understanding of the various components Drupal comprises and the ways they all interconnect. A consequence of our extensive development history with Drupal is that we’ve built up a considerable “product knowledge”, so we know what modules best suit what application requirements and so forth.