Reorganization of ties

app/models/activity.rb

@@ -1,4 +1,20 @@
+# Activities follow the {Activity Streams}[http://activitystrea.ms/] standard.
+#
+# == Activities and Ties
+# Every activity is attached to a Tie, which defines the sender, the receiver and
+# the relation in which the activity is transferred
+#
+# == Wall
+# The Activity.wall(ties) scope provides all the activities attached to a set of ties
+#
 class Activity < ActiveRecord::Base
+  scope :wall, lambda { |ties|
+    select("DISTINCT activities.*").
+      roots.
+      where(:tie_id => ties).
+      order("created_at desc")
+  }
+
   has_ancestry
 
   belongs_to :activity_verb
@@ -44,12 +60,4 @@ def liked_by?(user)
     liked_by(user).present?
   end
 
-  class << self
-    def wall(ties_query)
-      select( "DISTINCT activities.*").
-        roots.
-        where("activities.tie_id IN (#{ ties_query })").
-        order("created_at desc")
-    end
-  end
 end

app/models/actor.rb

@@ -2,14 +2,24 @@
 class Actor < ActiveRecord::Base
   include SocialStream::Models::Supertype
 
-  has_many :ties,
+  has_many :sent_ties,
+           :class_name => "Tie",
            :foreign_key => 'sender_id',
-           :include => [ :receiver, :relation ],
+           :dependent => :destroy
+
+  has_many :received_ties,
+           :class_name => "Tie",
+           :foreign_key => 'receiver_id',
            :dependent => :destroy
 
   # The subject instance for this actor
   def subject
     subtype_instance ||
       activity_object.try(:object)
   end
+
+  # All the ties sent or received by this actor
+  def ties
+    Tie.sent_or_received_by(self)
+  end
 end

app/models/tie.rb

@@ -14,6 +14,14 @@
 # == Inverse ties
 # Relations can have its inverse. When a tie is establised, an inverse tie is establised
 # as well.
+#
+# == Scopes
+# There are several scopes defined:
+# * sent_by(actor), ties whose sender is actor
+# * received_by(actor), ties whose receiver is actor
+# * sent_or_received_by(actor), the union of the former
+# * inverse(tie), the inverse of tie
+#
 class Tie < ActiveRecord::Base
   # Avoids loops at create_inverse after save callback
   attr_accessor :_without_inverse
@@ -42,6 +50,12 @@ class Tie < ActiveRecord::Base
     where(:receiver_id => Actor_id(a))
   }
 
+  scope :sent_or_received_by, lambda { |a|
+    where(arel_table[:sender_id].eq(Actor_id(a)).
+          or(arel_table[:receiver_id].eq(Actor_id(a))))
+
+  }
+
   scope :inverse, lambda { |t|
     sent_by(t.receiver).
       received_by(t.sender).
@@ -187,18 +201,5 @@ def Actor_id(a)
         a.actor.id
       end
     end
-
-    def tie_ids_query(actor)
-      c = arel_table
-      d = c.alias
-
-      c.join(d).
-        on(d[:sender_id].eq(actor.id).
-        and(c[:receiver_id].eq(d[:receiver_id])).
-        and((c[:relation_id].eq(d[:relation_id]).or(c[:relation_id].eq(0))))).
-        project(c[:id]).
-        to_sql
-      "SELECT ties.id FROM ties INNER JOIN ties ties_2 ON ((ties_2.sender_id = #{ actor.id } AND ties_2.receiver_id = ties.receiver_id) AND (ties_2.relation_id = ties.relation_id OR ties.relation_id = #{ Relation.mode('User', 'User').find_by_name('Public').id }))"
-    end
   end
 end

lib/social_stream/models/actor.rb

@@ -15,7 +15,7 @@ module Actor
                  :email, :email=,
                  :permalink, :permalink=,
                  :disabled, :disabled=,
-                 :ties,
+                 :ties, :sent_ties, :received_ties,
                  :to => :actor!
       end