Wednesday, January 6, 2010

About Drupal Framework

Why Drupal? What's a Framework?

A brief history of web applications

I think about web technologies as a series of layers. At the bottom, you've got the computer hardware that hosts your site. At the top, you've got what you see in your web browser--a bunch of text, pictures, videos, and ways of interacting with that content. In the middle are all the bits and pieces that get put together to create what you see in your browser.

In the early days of the web, there were pretty much 3 layers between the hardware and your web pages: the operating system on the server, a program called a web server that sent the pages to your browser, and a collection of HTML files and images that contained the content.

Early on, web servers started handing off particular requests to other programs, which could generate HTML on the fly and do other actions. The earliest mechanism for this was called CGI (Common Gateway Interface), and it allowed programmers to process data sent by forms, store and retrieve data from databases. At this point we quickly got to the point where we had stacks of software that work together to make more dynamic web sites. One of the most popular stacks is called LAMP, for the Linux operating system, Apache Web server, MySQL database, and PHP (or Perl or Python) language. A programmer can write programs in PHP to interact with a database and give you pages that are not just static files stored on the server, but generated on the fly. These pieces were all in place and in fairly widespread use by 2000 or so. Programs written in PHP on the web have come to be called "Web Applications."

What's a web application?

Quite simply, a web application is just a program that runs on a web server that you access through a web browser. We've built web applications to manage client data for a legal association, manage photos, manage who on a team is going to come to each game, track time spent on tasks and projects, sell products through the web in both a wholesale/manufacturing environment and for retail, and many others. We've deployed web applications for managing the financial records for a business, manage contacts with clients, report on electricitly usage in a house, all kinds of things. Database applications can solve all kinds of business needs, in all kinds of ways. Web applications are simply database applications you can access with an Internet connection and your web browser.

Most web applications are built to solve one kind of problem, and solve it well. Often if you start with an application made for one purpose, it's very difficult to repurpose it for another. Content management systems are not usually interchangeable with contact management systems. If you deploy a system designed for making it easy to publish blog posts, you're not likely going to find it useful for selling products--you'll need a different system. A system built to manage games and sports teams is not likely going to work well for tracking recipes.

What's a Content Management System?

You'll hear them called a "CMS" for short. Content management systems are web applications that are built to manage content on a web site. Their job is to make it so that you can easily edit or add new content to your web site without needing special tools. There are hundreds of different CMSs out there, each with different strengths and weaknesses. We've worked extensively with Joomla, Word Press, MediaWiki, and several others, but Drupal is our core CMS these days--because it's flexible enough to do more than just manage content.

What's a Framework?

Let's peel back a layer and look at what's under the hood. A Content Management System is a particular kind of web application. A framework is a set of tools and a pre-defined architecture for building a web application. So you could quite easily build a content management system on top of a framework.

Have you heard of Ruby on Rails? Rails is a framework, written in the Ruby programming language. Other popular frameworks include Django, CakePHP, Symfony, and dozens of others.

Most frameworks provide a built-in architecture to rapidly develop a full-blown web application. They often tend to use a "Model-View-Controller" organization -- a common way of dividing up programming tasks into units that can be managed more effectively. The "Model" represents the various objects your application manipulates -- pages, customers, projects, addresses, whatever. The "View" is usually the layer that graphic designers work with, to provide a look-and-feel for the application. The "Controller" ties all the bits together, determines who can access what and how it all works. In grammar terms, elements of the model are nouns, the view is mostly adjectives, and controllers are the verbs.

Powerful stuff. Frameworks are great. Except there's one big problem with using a framework, when there's already a good application for you to use: you still have to build an application!

If you're building a web site to manage content, and you're starting with a framework like Rails, it's like building a car from a kit instead of buying one off the lot: you have to do a lot more work before you can start driving.

If you need an application to do something you can't do in an existing application, a framework may well be the way to go. But before doing that, first see if there's an application that does the job for you already. If there is, your first step becomes putting your data into the application, not building the application.

Drupal as a Framework

Drupal is a fine content management system all on its own. But its true strength is that it's flexible enough to do many things beyond just managing content, while remaining modular enough to keep it simple.

Drupal provides quite a lot of base functionality that developers can leverage to rapidly develop all kinds of applications. The key things include:

  • A complete user authentication system, with plug-ins for OpenID, LDAP, and many other systems
  • A robust role-based authorization model
  • Any number of "Content Types" may be defined, using default handlers overridden where necessary, for storing content objects and relationships
  • A flexible taxonomy system that can be used to categorize and tag content
  • The "Forms API" to make it simple to create, validate, and process forms and uploaded files
  • Multiple theme engines with a clear override system for theming individual elements and pages
  • A sophisticated URL-parsing system to hook functionality to particular paths
  • An extensive hook system allowing you to completely change the behavior of the application at a fundamental level
  • Built-in caching, Javascript and CSS optimization, and cache-busting features for a nice mix of performance and development flexibility, and
  • Thousands of additional modules to make all sorts of changes to the system, including workflow rules, e-commerce, access control, automatic image processing and much more.

That's just a taste of what you can do with Drupal. There's a very definite learning curve before you'll know how to do all of this--which is why it's worth hiring a company like us to get you started. But there's a similar learning curve involved in using any framework effectively, too. The difference is, with Drupal you can start with a working site and easily add features as you go.

Why wouldn't you use Drupal?

There are a lot more specific applications that do particular things, and do them well. Want to manage your customer relationships? SugarCRM is a good place to start. Manage your business finances? LedgerSMB. Have a standalone desktop application you can use offline? Not Drupal. We've recently used LimeSurvey for a couple projects that used very sophisticated question formats, and it still met the need better than the Quiz module in Drupal.

If your needs are limited, and your site is meant to have a single function, you might be able to start more quickly and with less cost with a more specific solution. But if you need to build something custom, we're not seeing very many applications that can't be done well in Drupal. There are people in the Drupal community building clones of popular sites like Facebook, Twitter, Flickr, Basecamp, YouTube, and others, just to see how well Drupal can do the job. All can be done pretty quickly by a knowledgeble Drupal person, without much custom code.

The other place we've been working without Drupal is on web applications that have a huge amount of Javascript. Drupal is fine as a back end for a lot of different systems, though in some cases a simple framework storing resources managed from the browser may be a better way of supporting heavy Javascript-based applications. We're doing this for some charting/dashboard systems and a management application that puts a lot of functionality into a single browser window.

How do you choose?

Pick the best tool for the job, accounting for your priorities.

If there's already an application that does exactly what you need, use it.

If you need a custom web application, and need to manage users, objects, authentication/authorization, workflow, and other common features, consider using Drupal as a framework.


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