whatis.rb

#  http://gist.github.com/16885

#  $ ./script/console 
#  Loading development environment (Rails 2.1.0)
#  >>
#  >> User.whatis :create!
#  File: /opt/local/lib/ruby/gems/1.8/gems/activerecord-2.1.0/lib/active_record/validations.rb:876
#  872:             end  
#  873:         
#  874:             # Creates an object just like Base.create but calls save! instead of save  
#  875:             # so an exception is raised if the record is invalid.  
#  876: >>>>        def create!(attributes = nil, &block)    <<<<<<<
#  877:               if attributes.is_a?(Array)  
#  878:                 attributes.collect { |attr| create!(attr, &block) }  
#  879:               else  
#  880:                 object = new(attributes)  
#  881:                 yield(object) if block_given?  
#  882:                 object.save!  
#  883:                 object  
#  884:               end  
#  885:             end  
#  886:         
#  => #<Method: Class(ActiveRecord::Validations::ClassMethods)#create!>
#  >> _.tmate
#  => #<Method: Class(ActiveRecord::Validations::ClassMethods)#create!>
#  >> 
#
#
#  Examples:
#  ActionView::Base.new.method(:link_to).whatis
#  ActionView::Base.new.method(:link_to).tmate       # opens TextMate or E TextEditor 
#  ActionView::Base.new.whatis :link_to              # instance method of AV::Base
#  ActionView::Base.whatis :link_sanitizer           # class method of AV::Base
#  ActionView::Base.whatis :link_to                  # instance method of AV::Base
#  ActionView::Base.whatis :calendar_date_select     # instance method of AV::Base
#  whatis ActionView::Base, :link_to                 # instance method of AV::Base
#  tmate :it                                         # opens source code of methodphitmane
#  
#  

module Whatis
  def self.open_textmate(file, line=1)
    return unless File.exist?(file)
    if /mswin32/ =~ RUBY_PLATFORM
      `start txmt://open?url=file://#{file}^&line=#{line}`
    else
      `open 'txmt://open?url=file://#{file}&line=#{line}'`
    end
    return
  end
  
  def self.print_file(file, line=1, lines_count = 15)
    return unless File.exist? file
    lines = File.read(file).split("\n")
    start_line = [line - lines_count/3, 0].max
    selected = (0..lines_count-1).map{|i| 
      line_no = i+start_line+1
      title = "#{line_no}: "
      title << (line_no==line ? '>' : ' ')*(9-title.length)
      "%s  %s  %s" % [ title, lines[line_no-1].to_s.rstrip ,  ("  <<<<<<<" if line_no==line) ]
    }
    puts "File: #{file}:#{line}"
    puts selected * "\n"
  end
  
  def self.get_method(caller, arg1, arg2)
    obj, meth = arg2 ? [arg1, arg2] : [caller, arg1]   
    return meth if meth.is_a? Method
    if obj.is_a?(Module) && (obj.method(meth) rescue nil).nil? && (get_instance(obj).method(meth) rescue nil)
      obj = get_instance(obj)
    end
    return obj.method(meth)
  end
  
  def self.get_instance(klass)
    klass = Class.new.send(:include, klass) if !klass.respond_to?(:allocate)
    return klass.allocate
  end
end

class Method
  SHOW_TRACE = false
  def trace_func event, file, line, id, binding, classname
    puts "%8s %s:%-2d %s %8s" % [event, file, line, id, classname] if SHOW_TRACE
    return unless event == 'call'
    set_trace_func nil 
    
    @file, @line = file, line
    raise :found
  end
  
  def location
    if @file.nil?
      args =[*(1..(arity<-1 ? -arity-1 : arity ))]
      
      set_trace_func method(:trace_func).to_proc
      #begin; call *args; rescue Exception=>e; y e.to_s; y e.backtrace; end
      call *args rescue nil
      set_trace_func nil 
      @file = File.expand_path(@file) if @file && File.exist?(File.expand_path(@file))
    end
    return [@file, @line] if File.exist?(@file.to_s)
  end
  
  def whatis;  Whatis.print_file(*location) if location; self end
  def tmate;  Whatis.open_textmate(*location) if location; self  end
  
  alias :tm :tmate
  alias :wh :whatis
end

class Object
  def whatis(arg1, arg2=nil)
    m = Whatis.get_method(self, arg1, arg2)
    m.whatis ;  m
  end
  
  def tmate(arg1, arg2=nil)
    m = Whatis.get_method(self, arg1, arg2)
    m.tmate ;  m
  end
  
  alias :tm :tmate
  alias :wh :whatis
end