Monday, 1 October 2012

MVC is Broken

If you look up the definition of MVC or Model View Controller, it will hail the definition as being able to change your front end without affecting other parts of the application and vice versa. This sounds great in theory, however this claim is nothing more than a blatant lie.

A failing of the architectural pattern comes from the whole codebase being tied to a specific stack. Take ASP.NET MVC. The domain logic will most likely be in C#. Therefore your models will be in C#. Your controllers will be in C#. Your views will be a mixture of C# and some form of a templating language.

If you want to change your stack to the "next big thing" you are forced to take a big bang approach. ASP.NET MVC won't be around forever. Being tied to a specific technology feels wrong. Therefore this coupling means your designers are forced to use the templating language that your framework supports. This should be a flexible option that should be easy to change, after all the MVC pattern states this as one of it's benefits.

Being tied to a specific technology leads onto our most recent project. One of our biggest and most important projects is a legacy Flash application. Back in the early 2000's it was a cutting edge application - consistent across all browsers, ajax style requests, responsive design, you name it.

That being said we all know Flash is on its way out, and there lies the problem. It took myself about two weeks to add a few text boxes to the app in my first year at Codeweavers, all because the UI code is so difficult to work with. The logic is mixed within the UI. Had the app been developed in a MVC style we would be in a position to replace the legacy UI with a modern alternative.

We make use of SOA or Service Oriented Architecture at Codeweavers, therefore it seemed a natural fit to apply this to our rewrite of our legacy application. I proposed a theory:

"for an application to be truly independent of the frontend and backend the code must be developed in different languages."

For example, I taught myself enough PHP to make a JSON request, perform some conditional logic and loop over a collection. With this I was able to recreate one of our applications that was powered by our backend C# services. I would not want to create an application in PHP, but using PHP as a templating language was a great fit. After all this is one of the intentions of the language. Limiting myself to just three simple PHP constructs I was forced to put all logic on the service in question.

This complete separation of concerns is made possible due to the fact it is simply not possible for code to leak between the layers due to the different languages used in the implementation. This means I could easily spin up numerous front end views while the backend remains unchanged. Likewise we could change the back end implementation from C# to another language. Providing the endpoints and request/responses match, the front end will still be functional. This full separation of concerns is what MVC style frameworks have failed to achieve.

In ten years from now it is hard to say what the web will look like. What I can guarantee is that the web will still be here. We'll still be making HTTP requests. We'll still be making back end services that powers much of the apps on the internet. One thing no one can really comment on is what the web will look like. One point we all could agree on is that HTML5 should be wide spread and no doubt "the next big thing" will be on the horizon. The great thing by taking the approach discussed previously is that Codeweavers will be in the position to change either the front end or back end of our codebase at any time. Precisely what the MVC pattern has failed to deliver.

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