lots of relations changes for speed and version management

[rails.git] / lib / diff_reader.rb

diff --git a/lib/diff_reader.rb b/lib/diff_reader.rb
index 3b13e94626cc301f941a103a8df812a1b7fc831a..217e9309d7329d681141fd3a1115a04b693cc6a0 100644 (file)
--- a/lib/diff_reader.rb
+++ b/lib/diff_reader.rb
@@ -18,7 +18,7 @@ class DiffReader
   # in OsmChange format. All diffs must be limited to a single changeset
   # given in +changeset+.
   def initialize(data, changeset)
-    @reader = XML::Reader.new data
+    @reader = XML::Reader.string(data)
     @changeset = changeset
   end
 
@@ -26,11 +26,12 @@ class DiffReader
   # Reads the next element from the XML document. Checks the return value
   # and throws an exception if an error occurred.
   def read_or_die
-    # NOTE: XML::Reader#read returns 0 for EOF and -1 for error.
-    # we allow an EOF because we are expecting this to always happen
-    # at the end of a document.
-    if @reader.read < 0
-      raise APIBadUserInput.new("Unexpected end of XML document.")
+    # NOTE: XML::Reader#read returns false for EOF and raises an
+    # exception if an error occurs.
+    begin
+      @reader.read
+    rescue LibXML::XML::Error => ex
+      raise OSM::APIBadXMLError.new("changeset", xml, ex.message)
     end
   end
 
@@ -47,7 +48,7 @@ class DiffReader
       # read the first element
       read_or_die
 
-      begin
+      while @reader.node_type != 15 do # end element
         # because we read elements in DOM-style to reuse their DOM
         # parsing code, we don't always read an element on each pass
         # as the call to @reader.next in the innermost loop will take
@@ -57,7 +58,7 @@ class DiffReader
         else
           read_or_die
         end
-      end while @reader.node_type != 15 # end element
+      end 
     end
     read_or_die
   end
@@ -179,14 +180,23 @@ class DiffReader
         # delete action. this takes a payload in API 0.6, so we need to do
         # most of the same checks that are done for the modify.
         with_model do |model, xml|
-          new = model.from_xml_node(xml, false)
-          check(model, xml, new)
+          # delete doesn't have to contain a full payload, according to
+          # the wiki docs, so we just extract the things we need.
+          new_id = xml['id'].to_i
+          raise API::APIBadXMLError.new(model, xml, "ID attribute is required") if new_id.nil?
 
           # if the ID is a placeholder then map it to the real ID
           model_sym = model.to_s.downcase.to_sym
-          is_placeholder = ids[model_sym].include? new.id
-          id = is_placeholder ? ids[model_sym][new.id] : new.id
+          is_placeholder = ids[model_sym].include? new_id
+          id = is_placeholder ? ids[model_sym][new_id] : new_id
 
+          # build the "new" element by modifying the existing one
+          new = model.find(id)
+          new.changeset_id = xml['changeset'].to_i
+          new.version = xml['version'].to_i
+          check(model, xml, new)
+
+          # fetch the matching old element from the DB
           old = model.find(id)
 
           # can a delete have placeholders under any circumstances?
@@ -197,7 +207,7 @@ class DiffReader
           xml_result = XML::Node.new model.to_s.downcase
           # oh, the irony... the "new" element actually contains the "old" ID
           # a better name would have been client/server, but anyway...
-          xml_result["old_id"] = new.id.to_s
+          xml_result["old_id"] = new_id.to_s
           result.root << xml_result
         end