master/lib/guard/watcher.rb
2011-10-09 15:54:24 -07:00

115 lines
3.8 KiB
Ruby

module Guard
# The watcher defines a RegExp that will be matched against file system modifications.
# When a watcher matches a change, an optional action block is executed to enable
# processing the file system change result.
#
class Watcher
attr_accessor :pattern, :action, :any_return
# Initialize a file watcher.
#
# @param [String, Regexp] pattern the pattern to be watched by the guard
# @param [Block] action the action to execute before passing the result to the Guard
# @param [Boolean] any_return allow the user to define return when using a block
#
def initialize(pattern, action = nil, any_return = false)
@pattern, @action, @any_return = pattern, action, any_return
@@warning_printed ||= false
# deprecation warning
if @pattern.is_a?(String) && @pattern =~ /(^(\^))|(>?(\\\.)|(\.\*))|(\(.*\))|(\[.*\])|(\$$)/
unless @@warning_printed
UI.info "*"*20 + "\nDEPRECATION WARNING!\n" + "*"*20
UI.info <<-MSG
You have a string in your Guardfile watch patterns that seem to represent a Regexp.
Guard matches String with == and Regexp with Regexp#match.
You should either use plain String (without Regexp special characters) or real Regexp.
MSG
@@warning_printed = true
end
UI.info "\"#{@pattern}\" has been converted to #{ Regexp.new(@pattern).inspect }\n"
@pattern = Regexp.new(@pattern)
end
end
# Finds the files that matches a Guard.
#
# @param [Guard::Guard] guard the guard which watchers are used
# @param [Array<String>] files the changed files
# @return [Array<Object>] the matched watcher response
def self.match_files(guard, files)
guard.watchers.inject([]) do |paths, watcher|
files.each do |file|
if matches = watcher.match_file?(file)
if watcher.action
result = watcher.call_action(matches)
if watcher.any_return
paths << result
elsif result.respond_to?(:empty?) && ! result.empty?
paths << Array(result)
end
else
paths << matches[0]
end
end
end
watcher.any_return ? paths : paths.flatten.map{|p| p.to_s}
end
end
# Test if a file would be matched by any of the Guards watchers.
#
# @param [Array<Guard::Guard>] guards the guards to use the watchers from
# @param [Array<String>] files the files to test
# @return [Boolean] Whether a file matches
#
def self.match_files?(guards, files)
guards.any? do |guard|
guard.watchers.any? do |watcher|
files.any? { |file| watcher.match_file?(file) }
end
end
end
# Test the watchers pattern against a file.
#
# @param [String] file the file to test
# @return [Boolean] whether the given file is matched
#
def match_file?(file)
if @pattern.is_a?(Regexp)
file.match(@pattern)
else
file == @pattern ? [file] : nil
end
end
# Test if any of the files is the Guardfile.
#
# @param [Array<String>] the files to test
# @return [Boolean] whether one of these files is the Guardfile
#
def self.match_guardfile?(files)
files.any? { |file| "#{ Dir.pwd }/#{ file }" == Dsl.guardfile_path }
end
# Executes a watcher action.
#
# @param [String, MatchData] the matched path or the match from the Regex
# @return [String] the final paths
#
def call_action(matches)
begin
@action.arity > 0 ? @action.call(matches) : @action.call
rescue Exception => e
UI.error "Problem with watch action!\n#{ e.message }\n\n#{ e.backtrace.join("\n") }"
end
end
end
end