Use a polymorphic association to model relation members and add

[rails.git] / app / models / relation.rb

diff --git a/app/models/relation.rb b/app/models/relation.rb
index 93e9379b68694901152881b1ba0c5e1d541d0e66..cd2d67cdde0b969020d88530fdc82748f6f19451 100644 (file)
--- a/app/models/relation.rb
+++ b/app/models/relation.rb
@@ -1,14 +1,17 @@
 class Relation < ActiveRecord::Base
   require 'xml/libxml'
   
+  set_table_name 'current_relations'
+
   belongs_to :user
 
+  has_many :old_relations, :foreign_key => 'id', :order => 'version'
+
   has_many :relation_members, :foreign_key => 'id'
   has_many :relation_tags, :foreign_key => 'id'
 
-  has_many :old_relations, :foreign_key => 'id', :order => 'version'
-
-  set_table_name 'current_relations'
+  has_many :containing_relation_members, :as => :member
+  has_many :containing_relations, :through => :containing_relation_members
 
   def self.from_xml(xml, create=false)
     begin
@@ -108,8 +111,8 @@ class Relation < ActiveRecord::Base
   # relationships, i.e. deliver referenced objects like we do with ways... 
   # FIXME: rip out the fucking SQL
   def self.find_for_nodes_and_ways(node_ids, way_ids)
-    return [] if node_ids.empty? and node_ids.empty?
-    relations = Array.new
+    relations = []
+
     if node_ids.length > 0
       relations += Relation.find_by_sql("select e.* from current_relations e,current_relation_members em where " +
             "e.visible=1 and " +
@@ -120,6 +123,8 @@ class Relation < ActiveRecord::Base
             "e.visible=1 and " +
             "em.id = e.id and em.member_type='way' and em.member_id in (#{way_ids.join(',')})")
     end
+
+    relations # if you don't do this then it returns nil and not []
   end
 
 
@@ -200,22 +205,49 @@ class Relation < ActiveRecord::Base
   end
 
   def preconditions_ok?
+    # These are hastables that store an id in the index of all 
+    # the nodes/way/relations that have already been added.
+    # Once we know the id of the node/way/relation exists
+    # we check to see if it is already existing in the hashtable
+    # if it does, then we return false. Otherwise
+    # we add it to the relevant hash table, with the value true..
+    # Thus if you have nodes with the ids of 50 and 1 already in the
+    # relation, then the hash table nodes would contain:
+    # => {50=>true, 1=>true}
+    nodes = Hash.new
+    ways = Hash.new
+    relations = Hash.new
     self.members.each do |m|
       if (m[0] == "node")
         n = Node.find(:first, :conditions => ["id = ?", m[1]])
         unless n and n.visible 
           return false
         end
+        if nodes[m[1]]
+          return false
+        else
+          nodes[m[1]] = true
+        end
       elsif (m[0] == "way")
         w = Way.find(:first, :conditions => ["id = ?", m[1]])
         unless w and w.visible and w.preconditions_ok?
           return false
         end
+        if ways[m[1]]
+          return false
+        else
+          ways[m[1]] = true
+        end
       elsif (m[0] == "relation")
         e = Relation.find(:first, :conditions => ["id = ?", m[1]])
         unless e and e.visible and e.preconditions_ok?
           return false
         end
+        if relations[m[1]]
+          return false
+        else
+          relations[m[1]] = true
+        end
       else
         return false
       end