getting coffeescript and handlebars to work with plugins

test plan:
  * checkout patchset 1 from https://gerrit.instructure.com/7469
  * symlink the canvalytics repo into vendor/plugins/
  * symlink public/plugins/canvalytics to vendor/plugins/canvalytics/public/
  * run guard, regenerate all files
  * make sure the route /analytics/course/<id>/user/<id> renders handlebars

unit tests not provided for this scaffolding stuff

Change-Id: Ibf626555cbb79a5a97d67286ef4a7d8f28f53de8
Reviewed-on: https://gerrit.instructure.com/7470
Reviewed-by: Ryan Florence <ryanf@instructure.com>
Tested-by: Hudson <hudson@instructure.com>

Gemfile

@@ -84,7 +84,6 @@ group :development do
   gem 'sexp_processor', '3.0.5'
   gem 'ya2yaml', '0.30'
   gem 'guard'
-  gem 'guard-coffeescript'
 end
 
 group :redis do

Guardfile

@@ -1,3 +1,7 @@
 guard 'coffeescript', :input => 'app/coffeescripts',  :output => 'public/javascripts/compiled'
 guard 'coffeescript', :input => 'spec/coffeescripts', :output => 'spec/javascripts'
 guard 'jst',          :input => 'app/views/jst',      :output => 'public/javascripts/jst'
+
+Dir[File.join(File.dirname(__FILE__),'vendor/plugins/*/Guardfile')].each do |g|
+  eval(File.read(g))
+end

guard/coffeescript.rb

@@ -0,0 +1,200 @@
+#
+# Copyright (c) 2010 - 2011 Michael Kessler
+#   with modifications by Instructure Inc, 2011
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+#
+
+require 'guard'
+require 'guard/guard'
+require 'guard/watcher'
+require 'coffee_script'
+
+module Guard
+
+  class CoffeeScript < Guard
+
+    module Formatter
+      class << self
+        def info(message, options = { }); ::Guard::UI.info(message, options); end
+        def error(message, options = { }); ::Guard::UI.error(color(message, ';31'), options); end
+        def success(message, options = { }); ::Guard::UI.info(color(message, ';32'), options); end
+        def notify(message, options = { }); ::Guard::Notifier.notify(message, options); end
+        private
+        def color(text, color_code); ::Guard::UI.send(:color_enabled?) ? "\e[0#{ color_code }m#{ text }\e[0m" : text; end
+      end
+    end
+
+    module Runner
+      class << self
+
+        def run(files, watchers, options = { })
+          notify_start(files, options)
+          changed_files, errors = compile_files(files, watchers, options)
+          notify_result(changed_files, errors, options)
+
+          [changed_files, errors.empty?]
+
+        rescue ExecJS::RuntimeError => e
+          Formatter.error("ExecJS engine error: " + e.message)
+        end
+
+        private
+
+        def notify_start(files, options)
+          message = options[:message] || (options[:noop] ? 'Verify ' : 'Compile ') + files.join(', ')
+          Formatter.info(message, :reset => true)
+        end
+
+        def compile_files(files, watchers, options)
+          errors        = []
+          changed_files = []
+          directories   = detect_nested_directories(watchers, files, options)
+
+          directories.each do |directory, scripts|
+            scripts.each do |file|
+              begin
+                content = compile(file, options)
+                changed_files << write_javascript_file(content, file, directory, options)
+              rescue Exception => e
+                error_message = file + ': ' + e.message.to_s
+                errors << error_message
+                Formatter.error(error_message)
+              end
+            end
+          end
+
+          [changed_files.compact, errors]
+        end
+
+        def compile(file, options)
+          file_options = options_for_file(file, options)
+          ::CoffeeScript.compile(File.read(file), file_options)
+        end
+
+        def options_for_file(file, options)
+          return options unless options[:bare].respond_to? :include?
+
+          file_options        = options.clone
+          filename            = file[/([^\/]*)\.coffee/]
+          file_options[:bare] = file_options[:bare].include?(filename)
+
+          file_options
+        end
+
+        def write_javascript_file(content, file, directory, options)
+          FileUtils.mkdir_p(File.expand_path(directory)) if !File.directory?(directory) && !options[:noop]
+          filename = File.join(directory, File.basename(file.gsub(/(js\.coffee|coffee)$/, 'js')))
+          File.open(File.expand_path(filename), 'w') { |f| f.write(content) } if !options[:noop]
+
+          filename
+        end
+
+        def detect_nested_directories(watchers, files, options)
+          return { options[:output] => files } if options[:shallow]
+
+          directories = { }
+
+          watchers.product(files).each do |watcher, file|
+            if matches = file.match(watcher.pattern)
+              target = matches[1] ? File.join(options[:output], File.dirname(matches[1])).gsub(/\/\.$/, '') : options[:output]
+              if directories[target]
+                directories[target] << file
+              else
+                directories[target] = [file]
+              end
+            end
+          end
+
+          directories
+        end
+
+        def notify_result(changed_files, errors, options = { })
+          if !errors.empty?
+            Formatter.notify(errors.join("\n"), :title => 'CoffeeScript results', :image => :failed, :priority => 2)
+          elsif !options[:hide_success]
+            message = "Successfully #{ options[:noop] ? 'verified' : 'generated' } #{ changed_files.join(', ') }"
+            Formatter.success(message)
+            Formatter.notify(message, :title => 'CoffeeScript results')
+          end
+        end
+
+      end
+    end
+
+    DEFAULT_OPTIONS = {
+        :bare         => false,
+        :shallow      => false,
+        :hide_success => false,
+        :noop         => false,
+        :all_on_start => false
+    }
+
+    def initialize(watchers = [], options = {})
+      watchers = [] if !watchers
+      defaults = DEFAULT_OPTIONS.clone
+
+      if options[:input]
+        defaults.merge!({ :output => options[:input] })
+        watchers << ::Guard::Watcher.new(%r{^#{ options.delete(:input) }/(.+\.coffee)$})
+      end
+
+      super(watchers, defaults.merge(options))
+    end
+
+    def start
+      run_all if options[:all_on_start]
+    end
+
+    def run_all
+      run_on_change(Watcher.match_files(self, Dir.glob(File.join('**/*/**', '*.coffee'))))
+    end
+
+    def run_on_change(paths)
+      changed_files, success = Runner.run(clean(paths), watchers, options)
+      notify changed_files
+
+      throw :task_has_failed unless success
+    end
+
+    def run_on_deletion(paths)
+      clean(paths).each do |file|
+        javascript = file.gsub(/(js\.coffee|coffee)$/, 'js')
+        File.remove(javascript) if File.exists?(javascript)
+      end
+    end
+
+    private
+
+    def notify(changed_files)
+      ::Guard.guards.each do |guard|
+        paths = Watcher.match_files(guard, changed_files)
+        guard.run_on_change paths unless paths.empty?
+      end
+    end
+
+    def clean(paths)
+      paths.uniq!
+      paths.compact!
+      paths.select { |p| p =~ /.coffee$/ && File.exists?(p) }
+    end
+
+  end
+end

lib/handlebars/handlebars.rb

@@ -31,12 +31,12 @@ class Handlebars
       path     = "#{compiled_path}/#{id}.js"
       dir      = File.dirname(path)
       source   = File.read(file)
-      js       = compile_template(source, id)
+      js       = compile_template(source, id, compiled_path =~ /vendor\/plugins\/([^\/]*)\// ? $1 : nil)
       FileUtils.mkdir_p(dir) unless File.exists?(dir)
       File.open(path, 'w') { |file| file.write(js) }
     end
 
-    def compile_template(source, id)
+    def compile_template(source, id, plugin=nil)
       require 'execjs'
       # if the first letter of the template name is "_", register it as a partial
       # ex: _foobar.handlebars or subfolder/_something.handlebars
@@ -52,7 +52,7 @@ class Handlebars
 !(function(){
   var template = Handlebars.template, templates = Handlebars.templates = Handlebars.templates || {};
   templates['#{id}'] = template(#{template});#{partial_registration}
-  define('jst/#{id}', ['compiled/handlebars_helpers'], function (Handlebars) {
+  define('#{plugin ? plugin + "/" : ""}jst/#{id}', ['compiled/handlebars_helpers'], function (Handlebars) {
     return templates['#{id}'];
   });
 })();