+ 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"
+ end
+
+ ##
+ # query changesets by bounding box, time, user or open/closed status.
+ def query
+ # create the conditions that the user asked for. some or all of
+ # these may be nil.
+ conditions = conditions_bbox(params['bbox'])
+ conditions = cond_merge conditions, conditions_user(params['user'])
+ conditions = cond_merge conditions, conditions_time(params['time'])
+ conditions = cond_merge conditions, conditions_open(params['open'])
+ conditions = cond_merge conditions, conditions_closed(params['closed'])
+
+ # create the results document
+ results = OSM::API.new.get_xml_doc
+
+ # add all matching changesets to the XML results document
+ Changeset.find(:all,
+ :conditions => conditions,
+ :limit => 100,
+ :order => 'created_at desc').each do |cs|
+ results.root << cs.to_xml_node
+ end
+
+ render :text => results.to_s, :content_type => "text/xml"
+ end
+
+ ##
+ # updates a changeset's tags. none of the changeset's attributes are
+ # user-modifiable, so they will be ignored.
+ #
+ # changesets are not (yet?) versioned, so we don't have to deal with
+ # history tables here. changesets are locked to a single user, however.
+ #
+ # after succesful update, returns the XML of the changeset.
+ def update
+ # request *must* be a PUT.
+ assert_method :put
+
+ changeset = Changeset.find(params[:id])
+ new_changeset = Changeset.from_xml(request.raw_post)
+
+ unless new_changeset.nil?
+ check_changeset_consistency(changeset, @user)
+ changeset.update_from(new_changeset, @user)
+ render :text => changeset.to_xml, :mime_type => "text/xml"
+ else
+
+ render :nothing => true, :status => :bad_request
+ end
+ end
+
+
+
+ ##
+ # list edits (open changesets) in reverse chronological order
+ def list
+ conditions = conditions_nonempty
+
+
+ # @changesets = Changeset.find(:all, :order => "closed_at DESC", :conditions => ['closed_at < ?', DateTime.now], :limit=> 20)
+
+
+ #@edit_pages, @edits = paginate(:changesets,
+ # :include => [:user, :changeset_tags],
+ # :conditions => conditions,
+ # :order => "changesets.created_at DESC",
+ # :per_page => 20)
+ #
+
+ @edits = Changeset.find(:all,
+ :order => "changesets.created_at DESC",
+ :conditions => conditions,
+ :limit => 20)
+
+ end
+
+ ##
+ # list edits (changesets) belonging to a user
+ def list_user
+ user = User.find_by_display_name(params[:display_name], :conditions => {:visible => true})
+
+ if user
+ @display_name = user.display_name
+ if not user.data_public? and @user != user
+ @edits = nil
+ render
+ else
+ conditions = cond_merge conditions, ['user_id = ?', user.id]
+ conditions = cond_merge conditions, conditions_nonempty
+ @edit_pages, @edits = paginate(:changesets,
+ :include => [:user, :changeset_tags],
+ :conditions => conditions,
+ :order => "changesets.created_at DESC",
+ :per_page => 20)
+ end
+ else
+ @not_found_user = params[:display_name]
+ render :template => 'user/no_such_user', :status => :not_found
+ end
+ end
+
+ ##
+ # list edits (changesets) belonging to a user
+ def rss
+ user = User.find_by_display_name(params[:display_name], :conditions => {:visible => true})
+
+ if user
+ @display_name = user.display_name
+ if not user.data_public? and @user != user
+ @edits = nil
+ render
+ else
+ conditions = cond_merge conditions, ['user_id = ?', user.id]
+ conditions = cond_merge conditions, conditions_nonempty
+ @edit_pages, @edits = paginate(:changesets,
+ :include => [:user, :changeset_tags],
+ :conditions => conditions,
+ :order => "changesets.created_at DESC",
+ :per_page => 20)
+ end
+ else
+ @not_found_user = params[:display_name]
+ render :template => 'user/no_such_user', :status => :not_found
+ end
+ end
+
+ ##
+ # list changesets in a bbox
+ def list_bbox
+ # support 'bbox' param or alternatively 'minlon', 'minlat' etc
+ if params['bbox']
+ bbox = params['bbox']
+ elsif params['minlon'] and params['minlat'] and params['maxlon'] and params['maxlat']
+ bbox = h(params['minlon']) + ',' + h(params['minlat']) + ',' + h(params['maxlon']) + ',' + h(params['maxlat'])
+ else
+ #TODO: fix bugs in location determination for history tab (and other tabs) then uncomment this redirect
+ #redirect_to :action => 'list'
+
+ # For now just render immediately, and skip the db
+ render
+ return
+ end
+
+ conditions = conditions_bbox(bbox);
+ conditions = cond_merge conditions, conditions_nonempty