refactor possible_members

* projects makes more sense when speaking of "possible_members"
* using named scopes results in one single query for the database

app/models/principal.rb

@@ -23,7 +23,9 @@ class Principal < ActiveRecord::Base
   named_scope :active, :conditions => "#{Principal.table_name}.type='Group' OR (#{Principal.table_name}.type='User' AND #{Principal.table_name}.status = 1)"
 
   named_scope :active_or_registered, :conditions => "#{Principal.table_name}.type='Group' OR (#{Principal.table_name}.type='User' AND (#{Principal.table_name}.status = 1 OR #{Principal.table_name}.status = 2))"
-  
+
+  named_scope :not_in_project, lambda { |project| {:conditions => "id NOT IN (select u.id from users as u, members as m, member_roles as r where m.id = r.member_id AND m.project_id = #{project.id} AND m.user_id = u.id)"}}
+
   named_scope :like, lambda {|q|
     s = "%#{q.to_s.strip.downcase}%"
     {:conditions => ["LOWER(login) LIKE :s OR LOWER(firstname) LIKE :s OR LOWER(lastname) LIKE :s OR LOWER(mail) LIKE :s", {:s => s}],
@@ -37,10 +39,6 @@ class Principal < ActiveRecord::Base
     to_s
   end
 
-  def self.possible_members(criteria, limit)
-    Principal.active_or_registered.like(criteria).find(:all, :limit => limit)
-  end
-
   def <=>(principal)
     if self.class.name == principal.class.name
       self.to_s.downcase <=> principal.to_s.downcase

app/models/project.rb

@@ -109,6 +109,10 @@ class Project < ActiveRecord::Base
     errors[:identifier].nil? && !(new_record? || identifier.blank?)
   end
 
+  def possible_members(criteria, limit)
+    Principal.active_or_registered.like(criteria).not_in_project(self).find(:all, :limit => limit)
+  end
+
   # returns latest created projects
   # non public projects will be returned only if user is a member of those
   def self.latest(user=nil, count=5)

app/views/projects/settings/_members.rhtml

@@ -1,7 +1,7 @@
 <%= error_messages_for 'member' %>
 <% roles = Role.find_all_givable
-	 available_principals = Principal.possible_members("", 100) - @project.principals %>
    members = @project.member_principals.find(:all, :include => [:roles, :principal, :member_roles])
+	 available_principals = @project.possible_members("", 100) %>
 
 <div class="splitcontentleft">
 <% if members.any? %>