remove Rails dependency

update documentation with instructions for Sinatra
include alternate content_tag and image_tag to remove ActionView dependency

README.markdown

@@ -139,7 +139,28 @@ You can optionally define a global configuration in `config/jitterbug.yml`. The
 
 Jitterbug uses [Imagemagick](http://www.imagemagick.org/script/index.php) to build the header images. It needs to be installed on your development and production machines, as do any fonts that you're using. The default location for fonts is `/lib/fonts` in your project.
 
-We've only used Jitterbug in Rails projects thus far, so currently there are a few Rails dependencies: `RAILS_ROOT`, `content_tag` and `image_tag`. If anyone adapts Jitterbug for use in [Sinatra](http://github.com/sinatra/sinatra/), [Merb](http://github.com/merb/merb) or elsewhere, please send us your patches.
+## Using Jitterbug with Sinatra
+
+Jitterbug doesn't require Rails, provided you override the default root path and environment variables:
+
+    require 'sinatra'
+
+    require 'jitterbug'
+    Jitterbug::root = File.dirname(__FILE__)
+    Jitterbug::environment = Sinatra::Application::environment.to_s    
+
+    helpers do
+      include Jitterbug
+    end
+
+`Jitterbug::root` is the root path, which should include folders like `public/`, `lib/` and `config/`.  
+`Jitterbug::environment` is the a string representing the current environment (e.g.: `"development"` or `"production"`). 
+
+These default to `RAILS_ROOT` and `RAILS_ENV`, which require Rails.
+
+Jitterbug will provide its own `content_tag` and `image_tag` if ActionView isn't included.
+
+I've only tested this with Sinatra so far. Patches for Merb and other non-Rails systems would be very welcome.
 
 ## Compatibility and Font Types
 

lib/jitterbug.rb

@@ -1,6 +1,6 @@
-require 'jitterbug/config'
-require 'jitterbug/css'
-require 'jitterbug/fonts'
+require File.expand_path(File.join(File.dirname(__FILE__), 'jitterbug', 'config'))
+require File.expand_path(File.join(File.dirname(__FILE__), 'jitterbug', 'css'))
+require File.expand_path(File.join(File.dirname(__FILE__), 'jitterbug', 'fonts'))
 require 'md5'
 
 module Jitterbug
@@ -11,17 +11,19 @@ def self.included(base)
 
   def jitterbug(label = '<jitterbug>', options = {})
     options = Jitterbug::Config.settings.merge(options)
+    root = Jitterbug::root
     hash = MD5.new("#{label}#{options.sort {|a, b| a[0].to_s <=> b[0].to_s}.to_s}")
-    path = "#{RAILS_ROOT}/public/#{options[:img_path]}/#{hash}.#{options[:format]}".gsub('//', '/')
+    path = "#{root}/public/#{options[:img_path]}/#{hash}.#{options[:format]}".gsub('//', '/')
     unless File.exist?(path)
       caption = options[:width] ? "-size #{options[:width]}x caption:'#{label}'" : "label:'#{label}'"
-      `mkdir -p #{"#{RAILS_ROOT}/public/#{options[:img_path]}".gsub('//', '/')}`
+      `mkdir -p #{"#{root}/public/#{options[:img_path]}".gsub('//', '/')}`
       `convert -background #{options[:background]} -fill "#{options[:color]}" \
         -font #{Jitterbug::Fonts.find(options[:font_dir], options[:font])} \
         -pointsize #{options[:size]} -blur 0x.3 #{caption} #{path}`
     end
     img_src   = "/#{options[:img_path]}/#{hash}.#{options[:format]}".gsub('//', '/')
     img_class = (['jitterbug'] << options[:class]).compact.join(' ')
+
     if options[:tag]
       content_tag(options[:tag], label, :class => img_class, :style => Jitterbug::Css.tag(img_src, options))
     elsif options[:fat]
@@ -31,4 +33,29 @@ def jitterbug(label = '<jitterbug>', options = {})
     end
   end
 
+  # add content_tag and image_tag if ActionView isn't included
+  unless (respond_to?('content_tag'))
+    def content_tag(tag, label, options)
+      "<#{tag} class=\"#{options[:class]}\" style=\"#{options[:style]}\">#{label}</#{tag}>"
+    end
+  end
+  unless (respond_to?('image_tag'))
+    def image_tag(img_src, options)
+      "<img src=\"#{img_src}\" alt=\"#{options[:alt]}\" title=\"#{options[:alt]}\" class=\"#{options[:class]}\"></img>"
+    end
+  end
+
+  # accessor methods, with defaults for Rails
+  def self.root
+    @@root ||= RAILS_ROOT
+  end
+  def self.root=(value)
+    @@root = value
+  end
+  def self.environment
+    @@environment ||= RAILS_ENV
+  end
+  def self.environment=(value)
+    @@environment = value
+  end
 end

lib/jitterbug/config.rb

@@ -1,6 +1,6 @@
 module Jitterbug
   module Config
-    
+
     @@settings = { :background => 'transparent',
                    :color      => 'black',
                    :font       => '*',
@@ -9,16 +9,16 @@ module Config
                    :img_path   => '/content/jitterbug/',
                    :size       => 16 }
 
-    def self.read
-      config = "#{RAILS_ROOT}/config/jitterbug.yml"
+    def self.read      
+      config = "#{Jitterbug::root}/config/jitterbug.yml"
       if File.exist?(config)
-        YAML.load_file(config)[RAILS_ENV].each {|key, value| @@settings[key.to_sym] = value}
+        YAML.load_file(config)[Jitterbug::environment].each {|key, value| @@settings[key.to_sym] = value}
       end
     end
 
     def self.settings
       @@settings
     end
-    
+
   end
 end

lib/jitterbug/fonts.rb

@@ -2,7 +2,7 @@ module Jitterbug
   module Fonts
 
     def self.find(_path, _font)
-      path = "#{RAILS_ROOT}/#{_path}/*#{_font}*".gsub('//', '/')
+      path = "#{Jitterbug::root}/#{_path}/*#{_font}*".gsub('//', '/')
       font = Dir.glob(path)
       case font.size
         when 0: raise "*** Jitterbug Error: Font '#{_font}' could not be found in #{_path}"