added comment for future generations

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

diff --git a/app/models/way.rb b/app/models/way.rb
index f608dccc88c71b774b0073ddc98bc2db93f034f2..8788bd671b1e2ffdd9b1c9bd82c8f371edabc45a 100644 (file)
--- a/app/models/way.rb
+++ b/app/models/way.rb
@@ -25,6 +25,7 @@ class Way < ActiveRecord::Base
   validates_numericality_of :id, :on => :update, :integer_only => true
   validates_associated :changeset
 
+  # Read in xml as text and return it's Way object representation
   def self.from_xml(xml, create=false)
     begin
       p = XML::Parser.string(xml)
@@ -41,27 +42,27 @@ class Way < ActiveRecord::Base
   def self.from_xml_node(pt, create=false)
     way = Way.new
 
-    if !create and pt['id'] != '0'
-      way.id = pt['id'].to_i
-    end
-    
+    raise OSM::APIBadXMLError.new("way", pt, "Version is required when updating") unless create or not pt['version'].nil?
     way.version = pt['version']
-    raise OSM::APIBadXMLError.new("node", pt, "Changeset is required") if pt['changeset'].nil?
+    raise OSM::APIBadXMLError.new("way", pt, "Changeset id is missing") if pt['changeset'].nil?
     way.changeset_id = pt['changeset']
 
-    # This next section isn't required for the create, update, or delete of ways
-    if create
-      way.timestamp = Time.now.getutc
-      way.visible = true
-    else
-      if pt['timestamp']
-        way.timestamp = Time.parse(pt['timestamp'])
-      end
-      # if visible isn't present then it defaults to true
-      way.visible = (pt['visible'] or true)
+    unless create
+      raise OSM::APIBadXMLError.new("way", pt, "ID is required when updating") if pt['id'].nil?
+      way.id = pt['id'].to_i
+      # .to_i will return 0 if there is no number that can be parsed. 
+      # We want to make sure that there is no id with zero anyway
+      raise OSM::APIBadUserInput.new("ID of way cannot be zero when updating.") if way.id == 0
     end
 
+    # We don't care about the timestamp nor the visibility as these are either
+    # set explicitly or implicit in the action. The visibility is set to true, 
+    # and manually set to false before the actual delete.
+    way.visible = true
+
     pt.find('tag').each do |tag|
+      raise OSM::APIBadXMLError.new("way", pt, "tag is missing key") if tag['k'].nil?
+      raise OSM::APIBadXMLError.new("way", pt, "tag is missing value") if tag['v'].nil?
       way.add_tag_keyval(tag['k'], tag['v'])
     end
 
@@ -191,11 +192,6 @@ class Way < ActiveRecord::Base
     # in the hash to be overwritten.
     raise OSM::APIDuplicateTagsError.new("way", self.id, k) if @tags.include? k
 
-    # check tag size here, as we don't create a WayTag object until
-    # just before we save...
-    raise OSM::APIBadUserInput.new("Way #{self.id} has a tag with too long a key, '#{k}'.") if k.length > 255
-    raise OSM::APIBadUserInput.new("Way #{self.id} has a tag with too long a value, '#{k}'='#{v}'.") if v.length > 255
-
     @tags[k] = v
   end
 
@@ -209,17 +205,20 @@ class Way < ActiveRecord::Base
   end
 
   def update_from(new_way, user)
-    check_consistency(self, new_way, user)
-    unless new_way.preconditions_ok?(self.nds)
-      raise OSM::APIPreconditionFailedError.new("Cannot update way #{self.id}: data is invalid.")
+    Way.transaction do
+      self.lock!
+      check_consistency(self, new_way, user)
+      unless new_way.preconditions_ok?(self.nds)
+        raise OSM::APIPreconditionFailedError.new("Cannot update way #{self.id}: data is invalid.")
+      end
+      
+      self.changeset_id = new_way.changeset_id
+      self.changeset = new_way.changeset
+      self.tags = new_way.tags
+      self.nds = new_way.nds
+      self.visible = true
+      save_with_history!
     end
-
-    self.changeset_id = new_way.changeset_id
-    self.changeset = new_way.changeset
-    self.tags = new_way.tags
-    self.nds = new_way.nds
-    self.visible = true
-    save_with_history!
   end
 
   def create_with_history(user)
@@ -263,6 +262,7 @@ class Way < ActiveRecord::Base
     # provide repeatable reads for the used-by checks. this means it
     # shouldn't be possible to get race conditions.
     Way.transaction do
+      self.lock!
       check_consistency(self, new_way, user)
       rel = RelationMember.find(:first, :joins => :relation,
                              :conditions => [ "visible = ? AND member_type='Way' and member_id=? ", true, self.id])