X-Git-Url: https://git.openstreetmap.org/rails.git/blobdiff_plain/8c5638d6968be3286414f04b8dee2261ada84e76..c760891d634eff7b95b98d2bd88fc0d5535220bb:/app/controllers/changeset_controller.rb

diff --git a/app/controllers/changeset_controller.rb b/app/controllers/changeset_controller.rb
index 1041c7469..9152df816 100644
--- a/app/controllers/changeset_controller.rb
+++ b/app/controllers/changeset_controller.rb
@@ -2,10 +2,12 @@
 
 class ChangesetController < ApplicationController
   require 'xml/libxml'
+  require 'diff_reader'
 
-  before_filter :authorize, :only => [:create, :update, :delete]
-  before_filter :check_write_availability, :only => [:create, :update, :delete]
-  before_filter :check_read_availability, :except => [:create, :update, :delete]
+  before_filter :authorize, :only => [:create, :update, :delete, :upload, :include]
+  before_filter :check_write_availability, :only => [:create, :update, :delete, :upload, :include]
+  before_filter :check_read_availability, :except => [:create, :update, :delete, :upload, :download]
+  after_filter :compress_output
 
   # Create a changeset from XML.
   def create
@@ -23,4 +25,203 @@ class ChangesetController < ApplicationController
       render :nothing => true, :status => :method_not_allowed
     end
   end
+
+  def read
+    begin
+      changeset = Changeset.find(params[:id])
+      render :text => changeset.to_xml.to_s, :content_type => "text/xml"
+    rescue ActiveRecord::RecordNotFound
+      render :nothing => true, :status => :not_found
+    end
+  end
+  
+  def close 
+    begin
+      unless request.put?
+        render :nothing => true, :status => :method_not_allowed
+        return
+      end
+
+      changeset = Changeset.find(params[:id])
+
+      unless @user.id == changeset.user_id 
+        raise OSM::APIUserChangesetMismatchError 
+      end
+
+      changeset.open = false
+      changeset.save!
+      render :nothing => true
+    rescue ActiveRecord::RecordNotFound
+      render :nothing => true, :status => :not_found
+    end
+  end
+
+  ##
+  # insert a (set of) points into a changeset bounding box. this can only
+  # increase the size of the bounding box. this is a hint that clients can
+  # set either before uploading a large number of changes, or changes that
+  # the client (but not the server) knows will affect areas further away.
+  def include
+    # only allow POST requests, because although this method is
+    # idempotent, there is no "document" to PUT really...
+    if request.post?
+      cs = Changeset.find(params[:id])
+
+      # check user credentials - only the user who opened a changeset
+      # may alter it.
+      unless @user.id == changeset.user_id 
+        raise OSM::APIUserChangesetMismatchError 
+      end
+
+      # keep an array of lons and lats
+      lon = Array.new
+      lat = Array.new
+
+      # the request is in pseudo-osm format... this is kind-of an
+      # abuse, maybe should change to some other format?
+      doc = XML::Parser.string(request.raw_post).parse
+      doc.find("//osm/node").each do |n|
+        lon << n['lon'].to_f * SCALE
+        lat << n['lat'].to_f * SCALE
+      end
+
+      # add the existing bounding box to the lon-lat array
+      lon << cs.min_lon unless cs.min_lon.nil?
+      lat << cs.min_lat unless cs.min_lat.nil?
+      lon << cs.max_lon unless cs.max_lon.nil?
+      lat << cs.max_lat unless cs.max_lat.nil?
+
+      # collapse the arrays to minimum and maximum
+      cs.min_lon, cs.min_lat, cs.max_lon, cs.max_lat = 
+        lon.min, lat.min, lon.max, lat.max
+
+      # save the larger bounding box and return the changeset, which
+      # will include the bigger bounding box.
+      cs.save!
+      render :text => cs.to_xml.to_s, :content_type => "text/xml"
+
+    else
+      render :nothing => true, :status => :method_not_allowed
+    end
+
+  rescue ActiveRecord::RecordNotFound
+    render :nothing => true, :status => :not_found
+  rescue OSM::APIError => ex
+    render ex.render_opts
+  end
+
+  ##
+  # Upload a diff in a single transaction.
+  #
+  # This means that each change within the diff must succeed, i.e: that
+  # each version number mentioned is still current. Otherwise the entire
+  # transaction *must* be rolled back.
+  #
+  # Furthermore, each element in the diff can only reference the current
+  # changeset.
+  #
+  # Returns: a diffResult document, as described in 
+  # http://wiki.openstreetmap.org/index.php/OSM_Protocol_Version_0.6
+  def upload
+    # only allow POST requests, as the upload method is most definitely
+    # not idempotent, as several uploads with placeholder IDs will have
+    # different side-effects.
+    # see http://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html#sec9.1.2
+    unless request.post?
+      render :nothing => true, :status => :method_not_allowed
+      return
+    end
+
+    # access control - only the user who created a changeset may
+    # upload to it.
+    unless @user.id == changeset.user_id 
+      raise OSM::APIUserChangesetMismatchError 
+    end
+
+    changeset = Changeset.find(params[:id])
+    
+    diff_reader = DiffReader.new(request.raw_post, changeset)
+    Changeset.transaction do
+      result = diff_reader.commit
+      render :text => result.to_s, :content_type => "text/xml"
+    end
+    
+  rescue ActiveRecord::RecordNotFound
+    render :nothing => true, :status => :not_found
+  rescue OSM::APIError => ex
+    render ex.render_opts
+  end
+
+  ##
+  # download the changeset as an osmChange document.
+  #
+  # to make it easier to revert diffs it would be better if the osmChange
+  # format were reversible, i.e: contained both old and new versions of 
+  # modified elements. but it doesn't at the moment...
+  #
+  # this method cannot order the database changes fully (i.e: timestamp and
+  # version number may be too coarse) so the resulting diff may not apply
+  # to a different database. however since changesets are not atomic this 
+  # behaviour cannot be guaranteed anyway and is the result of a design
+  # choice.
+  def download
+    changeset = Changeset.find(params[:id])
+    
+    # get all the elements in the changeset and stick them in a big array.
+    elements = [changeset.old_nodes, 
+                changeset.old_ways, 
+                changeset.old_relations].flatten
+    
+    # sort the elements by timestamp and version number, as this is the 
+    # almost sensible ordering available. this would be much nicer if 
+    # global (SVN-style) versioning were used - then that would be 
+    # unambiguous.
+    elements.sort! do |a, b| 
+      if (a.timestamp == b.timestamp)
+        a.version <=> b.version
+      else
+        a.timestamp <=> b.timestamp 
+      end
+    end
+    
+    # create an osmChange document for the output
+    result = OSM::API.new.get_xml_doc
+    result.root.name = "osmChange"
+
+    # generate an output element for each operation. note: we avoid looking
+    # at the history because it is simpler - but it would be more correct to 
+    # check these assertions.
+    elements.each do |elt|
+      result.root <<
+        if (elt.version == 1) 
+          # first version, so it must be newly-created.
+          created = XML::Node.new "create"
+          created << elt.to_xml_node
+        else
+          # get the previous version from the element history
+          prev_elt = elt.class.find(:first, :conditions => 
+                                    ['id = ? and version = ?',
+                                     elt.id, elt.version])
+          unless elt.visible
+            # if the element isn't visible then it must have been deleted, so
+            # output the *previous* XML
+            deleted = XML::Node.new "delete"
+            deleted << prev_elt.to_xml_node
+          else
+            # must be a modify, for which we don't need the previous version
+            # yet...
+            modified = XML::Node.new "modify"
+            modified << elt.to_xml_node
+          end
+        end
+    end
+
+    render :text => result.to_s, :content_type => "text/xml"
+            
+  rescue ActiveRecord::RecordNotFound
+    render :nothing => true, :status => :not_found
+  rescue OSM::APIError => ex
+    render ex.render_opts
+  end
+
 end