I use the YUI Compressor to minify Javascript and CSS files. By default it will remove all comments from the files but there is a simple solution to retaining comments in files, which is often necessary for example when preserving copyright and license terms of use etc.
Default example
Take the following Javascript file example:
/* some copyright information here */
function foo(var1, var2, var3) {
/* comment blah blah blah */
if(var1 == var2) {
// do something
}
}
When minified using the default YUI Compressor settings, the resulting output will look like this:
function foo(c,b,a){if(c==b){}};
Note that all comments have been removed and the variable names have been replaced with shorter names.
How to preserve comments with the YUI Compressor
To preserve comments, simply add a ! after the opening /* and that comment block will remain in the compressed output. The ! will be stripped because it is unecessary and was not present in the original code.
Changing the above example to retain the first comment:
/*! some copyright information here */
function foo(var1, var2, var3) {
/* comment blah blah blah */
if(var1 == var2) {
// do something
}
}
When run through the YUI Compressor it will now look like this:
/* some copyright information here */
function foo(c,b,a){if(c==b){}};
Other tips and tricks
I’ll post some other tips and tricks when using the YUI Compressor in the coming weeks to change other formatting etc.
