gravtastic.rb

#

Gravtastic is a small module which quickly generates a Gravatar URL. Just include in your class!

 
             		           
                               
                            
                 #               
               
Gravatar uses an MD5 hash of the users email to locate their avatar.
             		                            
require 'digest/md5'
require 'gravtastic/version'

module Gravtastic
  
             		           
                               
                            
                 #               
               
When you include Gravtastic, Ruby automatically calls this method
with the class you called it in. It allows us extend the class with the
#gravtastic method.
             		                            
  def self.included(model)
    model.extend StageOne
  end
  
             		           
                               
                            
                 #               
               
Sets the model's default attributes. It is called when you use 
#gravtastic in your model.
             		                            
  def self.configure(model, *args, &blk)
    options = args.last.is_a?(Hash) ? args.pop : {}

    model.gravatar_defaults = {
      :rating => 'PG',
      :secure => false,
      :filetype => :png
    }.merge(options)
    
             		           
                               
                            
                 #               
               
The method where Gravtastic get the users' email from defaults to #email.
             		                            
    model.gravatar_source = args.first || :email
  end
             		           
                               
                            
                 #               
               
We include Gravtastic in multiple stages. This is mainly so that if you 
include Gravastic in a superclass (something like ActiveRecord::Base) 
then it only adds the relevant methods to the classes which actually use 
it.
             		                            
  module StageOne
    def gravtastic(*args, &blk)
      extend ClassMethods
      include InstanceMethods
      Gravtastic.configure(self, *args, &blk)
      self
    end
    
             		           
                               
                            
                 #               
               
All these aliases deal with pervious bad design decisions. Let that be a 
lesson, name things simply, try not to follow fads and try not to break 
backwards compatibility.
             		                            
    alias_method :gravtastic!,    :gravtastic
    alias_method :has_gravatar,   :gravtastic
    alias_method :is_gravtastic,  :gravtastic
    alias_method :is_gravtastic!, :gravtastic
  end

  module ClassMethods
    attr_accessor :gravatar_source, :gravatar_defaults
    
             		           
                               
                            
                 #               
               
Gravtastic abbreviates certain params so that it produces the smallest
possible URL. Every byte counts.
             		                            
    def gravatar_abbreviations
      { :size => 's',
        :default => 'd',
        :rating => 'r'
      }
    end
  end

  module InstanceMethods
    
             		           
                               
                            
                 #               
               
The raw MD5 hash of the users' email. Gravatar is particularly tricky as
it downcases all emails. This is really the guts of the module, 
everything else is just convenience.
             		                            
    def gravatar_id
      Digest::MD5.hexdigest(send(self.class.gravatar_source).to_s.downcase)
    end
    
             		           
                               
                            
                 #               
               
Constructs the full Gravatar url.
             		                            
    def gravatar_url(options={})
      options = self.class.gravatar_defaults.merge(options)
      gravatar_hostname(options.delete(:secure)) +
        gravatar_filename(options.delete(:filetype)) +
        url_params_from_hash(options)
    end

  private
    
             		           
                               
                            
                 #               
               
Creates a params hash like "?foo=bar" from a hash like {'foo' => 'bar'}.
The values are sorted so it produces deterministic output (and can 
therefore be tested easily).
             		                            
    def url_params_from_hash(hash)
      '?' + hash.map do |key, val|
        [self.class.gravatar_abbreviations[key.to_sym] || key.to_s, val.to_s ].join('=')
      end.sort.join('&')
    end
             		           
                               
                            
                 #               
               
Returns either Gravatar's secure hostname or not.
             		                            
    def gravatar_hostname(secure)
      'http' + (secure ? 's://secure.' : '://') + 'gravatar.com/avatar/'
    end
    
             		           
                               
                            
                 #               
               
Munges the ID and the filetype into one. Like "abc123.png"
             		                            
    def gravatar_filename(filetype)
      "#{gravatar_id}.#{filetype}"
    end
  end

end