+ # 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
+
+ if params[:display_name]
+ user = User.find_by_display_name(params[:display_name], :conditions => { :visible => true })
+
+ if user
+ if user.data_public? or user == @user
+ conditions = cond_merge conditions, ['user_id = ?', user.id]
+ else
+ conditions = cond_merge conditions, ['false']
+ end
+ elsif request.format == :html
+ @title = t 'user.no_such_user.title'
+ @not_found_user = params[:display_name]
+ render :template => 'user/no_such_user', :status => :not_found
+ end
+ end
+
+ if params[:bbox]
+ bbox = params[:bbox]
+ elsif params[:minlon] and params[:minlat] and params[:maxlon] and params[:maxlat]
+ bbox = params[:minlon] + ',' + params[:minlat] + ',' + params[:maxlon] + ',' + params[:maxlat]
+ end
+
+ if bbox
+ conditions = cond_merge conditions, conditions_bbox(bbox)
+ bbox = BoundingBox.from_s(bbox)
+ bbox_link = render_to_string :partial => "bbox", :object => bbox
+ end
+
+ if user
+ user_link = render_to_string :partial => "user", :object => user
+ end
+
+ if user and bbox
+ @title = t 'changeset.list.title_user_bbox', :user => user.display_name, :bbox => bbox.to_s
+ @heading = t 'changeset.list.heading_user_bbox', :user => user.display_name, :bbox => bbox.to_s
+ @description = t 'changeset.list.description_user_bbox', :user => user_link, :bbox => bbox_link
+ elsif user
+ @title = t 'changeset.list.title_user', :user => user.display_name
+ @heading = t 'changeset.list.heading_user', :user => user.display_name
+ @description = t 'changeset.list.description_user', :user => user_link
+ elsif bbox
+ @title = t 'changeset.list.title_bbox', :bbox => bbox.to_s
+ @heading = t 'changeset.list.heading_bbox', :bbox => bbox.to_s
+ @description = t 'changeset.list.description_bbox', :bbox => bbox_link
+ else
+ @title = t 'changeset.list.title'
+ @heading = t 'changeset.list.heading'
+ @description = t 'changeset.list.description'
+ end
+
+ @edit_pages, @edits = paginate(:changesets,
+ :include => [:user, :changeset_tags],
+ :conditions => conditions,
+ :order => "changesets.created_at DESC",
+ :per_page => 20)
+ end
+
+private
+ #------------------------------------------------------------
+ # utility functions below.
+ #------------------------------------------------------------
+
+ ##
+ # merge two conditions
+ def cond_merge(a, b)
+ if a and b
+ a_str = a.shift
+ b_str = b.shift
+ return [ a_str + " AND " + b_str ] + a + b
+ elsif a
+ return a
+ else b
+ return b
+ end
+ end
+
+ ##
+ # if a bounding box was specified then parse it and do some sanity
+ # checks. this is mostly the same as the map call, but without the
+ # area restriction.
+ def conditions_bbox(bbox)
+ unless bbox.nil?
+ raise OSM::APIBadUserInput.new("Bounding box should be min_lon,min_lat,max_lon,max_lat") unless bbox.count(',') == 3
+ bbox = sanitise_boundaries(bbox.split(/,/))
+ raise OSM::APIBadUserInput.new("Minimum longitude should be less than maximum.") unless bbox[0] <= bbox[2]
+ raise OSM::APIBadUserInput.new("Minimum latitude should be less than maximum.") unless bbox[1] <= bbox[3]
+ return ['min_lon < ? and max_lon > ? and min_lat < ? and max_lat > ?',
+ bbox[2] * GeoRecord::SCALE, bbox[0] * GeoRecord::SCALE, bbox[3]* GeoRecord::SCALE, bbox[1] * GeoRecord::SCALE]
+ else
+ return nil
+ end