I've been doing Drupal development on-and off for nearly three years now and it's always been frustrating. I'm a pretty vocal and animated kind of person too, so my co-workers soon came to know me as the anti-Drupal guy, which can be pretty rough when your employer has chosen to standardise on the platform. Now that I'm finally out of the Drupal world, I wanted to write a little about the platform, specifically speaking to its weaknesses and failures.
My hope here is two fold: (a) that this post serve as a means of communicating to the thousands of frustrated developers out there that they're not alone in their pain, and (b) that perhaps some of this post will help development shops choose Drupal where appropriate and other technologies when it is not.
For the Drupal fan(girl|boy)s, I ask only that you try to read this with an open and constructive mind. While I may rant and curse about Drupal in my Twitter feed, I've tried very hard to make this an unemotional, hopefully useful post about something I've spent a lot of time thinking about and working with.
Drupal Ideology
It seems to be a mantra within the community: "You don't even need to write code". The Drupal ideology is user-centric, choosing ease-of-use over performance at every turn. There's nothing wrong with this of course, so long as your goal is to let unskilled people make websites. However if your priority is a performant application capable of handling a lot of traffic, you're going to have a number of problems.
Some examples of prioritising user-focus over performance:
- Silent failures are the bane of any developer's existence. It's important to know when a variable isn't defined, or that writing a record to the database failed, or that a file didn't upload properly. Drupal suppresses such messages by default, and as a result nearly every contrib module in the community is so riddled with errors and warnings that development with these messages enabled is near impossible.
- Views, the de-facto standard way to store and retrieve data from your database, writes queries to the database, so that in order to perform a query against the database, you must first fetch the query from the database. Similar inefficiencies can be found in other "standard" modules like CCK and Panels.
- Drupal relies almost entirely on caching in order to function at all. Without caching, a method usually reserved for high to extreme traffic situations, Drupal can't handle even a small number of concurrent visitors. Indeed, some projects I've seen have taken more than 10minutes to load a single page, even in development where there was only one connection in use.
Drupal Magic
It's a term celebrated by many in the community. The idea being that Drupal does a mountain of work for you, so you don't have to worry about it. The only problem is that when you're trying to build a finely-tuned application, most of this magic either gets in the way, or even works against you. You get 80% of the way there with Drupal and its contrib modules, and then spend three months fighting the whole application, undoing the damage it's done, just to get what you need out of your website.
The hook-dependent system requires and fosters this anti-pattern. Re-using code often means unpredictable, site-wide changes. A property is written in module X, overwritten in module Y, and altogether removed in module Z, and there's no way to be certain that these functions will execute in a predictable order.
This problem is notably worse when it comes to new developers on a project, since they will undoubtedly not be privy to the magic that is running under the hood, and will have a difficult time discovering it on their own. To those who will answer this with "the project simply needs better documentation", I respectfully suggest that a good code base is easy to understand, and doesn't require a manual that is usually out of date.
To work with Drupal Magic is to attempt to produce useful code against an unordered, uncontrolled, grep-to-find-what-is-going-on-dependent architecture.
Drupal Community
For all the victories in community engagement Drupal has achieved (a massive, diverse and engaged membership), it's the glaring failures that make the whole project a miserable situation for developers. I've already mentioned the standardising on inefficient modules, but I haven't talked about the mountains of really horribly written code yet. Drupal Core, for what it does, is pretty efficient, but too many contrib modules are written by inexperienced developers, or are simply incapable of scaling to enterprise-level capacity. The result of this is that non-developers (managers, sometimes even clients) will point to the functionality of module X and insist: "don't redesign the wheel, just use that", and you spend the next three weeks trying to work around the poor design of said module, eventually being forced to write garbage that talks to garbage.
Often the perceived strength of the community is Drupal's greatest weakness. Drupal is promoted based on its theoretically infinite feature set, but the reality is that in order to use every one of those contrib modules in your site, the memory footprint will be massive, the stability suspect, and the performance abysmal. And gods help you if you try this on a site with millions of users or a similar number of content nodes.
Drupal Establishment
None of this is a problem however if Drupal is used where its features and shortcomings are both understood and accepted as the nature of the platform. Drupal is a great tool in some situations and a horrible burden in others. Sadly, this has not yet sunk in with many of the decision-makers in the web development community. Drupal is being used and promoted as a solution hammer, with every potential development project, a Drupal-shaped nail.
This has a number of negative outcomes, the most dangerous of which is a lack of skill diversity in developers. Companies that insist on Drupal-centric development are in fact promoting ignorance of alternatives that might do a better job and that hurts everyone. Unless developers at these companies take it upon themselves to spend time outside of their 8-12 hour work day to write code for a different platform or language, this Drupal dependency will force their non-Drupal skills to atrophy, limiting their ability to produce good code in the future.
Conclusion
I'm finally at the end of my admittedly unenthusiastic involvement in the Drupal community. Whether the Drupal shops out there read this isn't really up to me, but I hope that this manages to help some people re-evaluate their devotion to the platform. Comments are welcome, so long as they're constructive (I moderate everything), but I'm not going to get into a shouting match on the Internet. If you think I'm wrong, we can talk about it in 5 years.