Concatenate and minify JavaScript on the fly OR at build time - ASP.NET MVC

Question

As an extension to this question here Linking JavaScript Libraries in User Controls I was after some examples of how people are concatenating and minifying JavaScript on the

Answer 1

Use either YUI Compressor or Dojo compressor. They both use the Rhino JS parsing engine which tokenizes your code, and will therefore only work if the code is valid code. If there is an error, they'll let you know (which is a nice bonus IMO!) Packer on the other hand, will pack your code even if it contains errors.

I use YUI in all my projects via build scripts. Never do it on the fly, it takes too long to do the compression. Both YUI and Dojo are Java based (ala Rhino) and if you do it on the fly, you'll be spawning background processes to generate the output - not good for performance. Always do it at build time.