less-watcher.coffee

less-watcher is a script that can watch a directory and recompile your .less styles if they change.

It's very useful for development as you don't need to think about recompiling your Less files. Search is done in a recursive manner so sub-directories are handled as well.

Usage:
  less-watcher -p [prefix] -d [directory]

Options:
  -d  Specify which directory to scan.                                                                         [default: "."]
  -p  Which prefix should the compiled files have? Default is style.less will be compiled to .less.style.css.  [default: ".less."]
  -h  Prints help                                                                                              [boolean]

Installing less-watcher is easy with npm:

  sudo npm install less-watcher

Run this to watch for changes in the current working directory:

  less-watcher

Run this to watch for changes in a specified directory:

  less-watcher -d ~/Desktop/my_project

less-watcher requires:

 
             		           
                               
                            
                                
               
Specify the command line arguments for the script (using optimist)
             		                            
usage = "Watch a directory and recompile .less styles if they change.\nUsage: less-watcher -p [prefix] -d [directory]."
specs = require('optimist')
        .usage(usage)

        .default('d', '.')
        .describe('d', 'Specify which directory to scan.')

        .default('p', '.less.')
        .describe('p', 'Which prefix should the compiled files have? Default is style.less will be compiled to .less.style.css.')

        .boolean('h')
        .describe('h', 'Prints help')
             		           
                               
                            
                                
               
Handle the special -h case
             		                            
if specs.parse(process.argv).h
    specs.showHelp()
    process.exit()
else
    argv = specs.argv
             		           
                               
                            
                                
               
Use watcher-lib, a library that abstracts away most of the implementation details.
This library also makes it possible to implement any watchers (see coffee-watcher for an example).
             		                            
watcher_lib = require 'watcher_lib'
             		           
                               
                            
                                
               
Searches through a directory structure for *.less files using find.
For each .less file it runs compileIfNeeded to compile the file if it's modified.
             		                            
findLessFiles = (dir) ->
    watcher_lib.findFiles('*.less', dir, compileIfNeeded)
             		           
                               
                            
                                
               
Keeps a track of modified times for .less files in a in-memory object,
if a .less file is modified it recompiles it using compileLessScript.



When starting the script all files will be recompiled.
             		                            
WATCHED_FILES = {}
compileIfNeeded = (file) ->
    watcher_lib.compileIfNeeded(WATCHED_FILES, file, compileLessScript)
             		           
                               
                            
                                
               
Compiles a file using lessc. Compilation errors are printed out to stdout.
             		                            
compileLessScript = (file) ->
    fnGetOutputFile = (file) -> file.replace(/([^\/\\]+)\.less/, "#{argv.p}$1.css")
    watcher_lib.compileFile("lessc #{ file }", file, fnGetOutputFile)
             		           
                               
                            
                                
               
Starts a poller that polls each second in a directory that's
either by default the current working directory or a directory that's passed through process arguments.
             		                            
watcher_lib.startDirectoryPoll(argv.d, findLessFiles)