Should I use a framework?

When to use a framework and when to write your own code

I am always asked at work why I don't just use a framework such as jQuery, prototype, YUI, MooTools etc rather than spend time writing my own code and its a fair point. I have spent time looking at the major frameworks and its all good code written by clever people and if you haven't got the time to spend then I would definitely recommend using a library. Then again if John Reisig had thought like that then millions of people would be using YUI instead of jQuery and Microsoft would be packaging another library with Visual Studio to handle selectors instead.

Libraries are good for many reasons they hide browser incompatibilities from the developer and its good for a team of developers to stick to a standard code base rather than all adding their own functions and bloating a site up with several versions of the same addEvent or toggleClass function.

The downside is that most libraries will contain lots of code that is never even used by the developer. If you're not even going to be using selectors to return DOM objects in your JavaScript and are just looking for a shorter version of document.getElementById then using $('#blah') is not the way to go. 

The other good thing about writing your own code is that you get to understand the language of your trade a whole lot better than if you just relied on a library. There is no better way in my opinion for learning anything that being thrown in at the deep end and having to sink or swim so to speak. Yes it takes much longer as you will have to read up about the early browser wars and compatibility issues, learn about objects and their properties and understand event models and script syntax but it will make you a much better programmer and when bugs appear due to a new version of Internet Explorer you won't have to wait for an update to your framework to be released.

As with all things its swings and roundabouts and just because I like to write my own code and know why things work the way they do does not mean I won't use a library. However having spent the time researching the language for my own code has given me invaluable knowledge and it helps being able to step through something like jQuery and actually understand what its doing and why rather than just knowing that it works.