Implemented changeset tags updating via the update method.

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

diff --git a/app/models/changeset.rb b/app/models/changeset.rb
index 446ca351de81cd4d574722630cc4785284ffd30f..047569dca5cf15db682c9c1fbd8fe72a85b3a942 100644 (file)
--- a/app/models/changeset.rb
+++ b/app/models/changeset.rb
@@ -15,6 +15,9 @@ class Changeset < ActiveRecord::Base
   validates_presence_of :user_id, :created_at
   validates_inclusion_of :open, :in => [ true, false ]
   
+  # over-expansion factor to use when updating the bounding box
+  EXPAND = 0.1
+
   # Use a method like this, so that we can easily change how we
   # determine whether a changeset is open, without breaking code in at 
   # least 6 controllers
@@ -46,6 +49,35 @@ class Changeset < ActiveRecord::Base
     return cs
   end
 
+  ##
+  # returns the bounding box of the changeset. it is possible that some
+  # or all of the values will be nil, indicating that they are undefined.
+  def bbox
+    @bbox ||= [ min_lon, min_lat, max_lon, max_lat ]
+  end
+
+  ##
+  # expand the bounding box to include the given bounding box. also, 
+  # expand a little bit more in the direction of the expansion, so that
+  # further expansions may be unnecessary. this is an optimisation 
+  # suggested on the wiki page by kleptog.
+  def update_bbox!(array)
+    # ensure that bbox is cached and has no nils in it. if there are any
+    # nils, just use the bounding box update to write over them.
+    @bbox = bbox.zip(array).collect { |a, b| a.nil? ? b : a }
+
+    # FIXME - this looks nasty and violates DRY... is there any prettier 
+    # way to do this? 
+    @bbox[0] = array[0] + EXPAND * (@bbox[0] - @bbox[2]) if array[0] < @bbox[0]
+    @bbox[1] = array[1] + EXPAND * (@bbox[1] - @bbox[3]) if array[1] < @bbox[1]
+    @bbox[2] = array[2] + EXPAND * (@bbox[2] - @bbox[0]) if array[2] > @bbox[2]
+    @bbox[3] = array[3] + EXPAND * (@bbox[3] - @bbox[1]) if array[3] > @bbox[3]
+
+    # update active record. rails 2.1's dirty handling should take care of
+    # whether this object needs saving or not.
+    self.min_lon, self.min_lat, self.max_lon, self.max_lat = @bbox
+  end
+
   def tags_as_hash
     return tags
   end
@@ -72,13 +104,13 @@ class Changeset < ActiveRecord::Base
   def save_with_tags!
     t = Time.now
 
+    # do the changeset update and the changeset tags update in the
+    # same transaction to ensure consistency.
     Changeset.transaction do
       # fixme update modified_at time?
       # FIXME there is no modified_at time, should it be added
       self.save!
-    end
 
-    ChangesetTag.transaction do
       tags = self.tags
       ChangesetTag.delete_all(['id = ?', self.id])
 
@@ -113,6 +145,7 @@ class Changeset < ActiveRecord::Base
     end
 
     el1['user'] = user_display_name_cache[self.user_id] unless user_display_name_cache[self.user_id].nil?
+    el1['uid'] = self.user_id.to_s if self.user.data_public?
 
     self.tags.each do |k,v|
       el2 = XML::Node.new('tag')
@@ -124,10 +157,36 @@ class Changeset < ActiveRecord::Base
     el1['created_at'] = self.created_at.xmlschema
     el1['open'] = self.open.to_s
 
-    # FIXME FIXME FIXME: This does not include changes yet! There is 
-    # currently no changeset_id column in the tables as far as I can tell,
-    # so this is just a scaffold to build on, not a complete to_xml
+    el1['min_lon'] = (bbox[0].to_f / GeoRecord::SCALE).to_s unless bbox[0].nil?
+    el1['min_lat'] = (bbox[1].to_f / GeoRecord::SCALE).to_s unless bbox[1].nil?
+    el1['max_lon'] = (bbox[2].to_f / GeoRecord::SCALE).to_s unless bbox[2].nil?
+    el1['max_lat'] = (bbox[3].to_f / GeoRecord::SCALE).to_s unless bbox[3].nil?
+    
+    # NOTE: changesets don't include the XML of the changes within them,
+    # they are just structures for tagging. to get the osmChange of a
+    # changeset, see the download method of the controller.
 
     return el1
   end
+
+  ##
+  # update this instance from another instance given and the user who is
+  # doing the updating. note that this method is not for updating the
+  # bounding box, only the tags of the changeset.
+  def update_from(other, user)
+    # ensure that only the user who opened the changeset may modify it.
+    unless user.id == self.user_id 
+      raise OSM::APIUserChangesetMismatchError 
+    end
+    
+    # can't change a closed changeset
+    unless open
+      raise OSM::APIChangesetAlreadyClosedError
+    end
+
+    # copy the other's tags
+    self.tags = other.tags
+
+    save_with_tags!
+  end
 end