+
+ ##
+ # 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 which haven't been redacted
+ # and stick them in a big array.
+ elements = [changeset.old_nodes.unredacted,
+ changeset.old_ways.unredacted,
+ changeset.old_relations.unredacted].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 changeset and user caches
+ changeset_cache = {}
+ user_display_name_cache = {}
+
+ # 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(changeset_cache, user_display_name_cache)
+ else
+ unless elt.visible
+ # if the element isn't visible then it must have been deleted
+ deleted = XML::Node.new "delete"
+ deleted << elt.to_xml_node(changeset_cache, user_display_name_cache)
+ else
+ # must be a modify
+ modified = XML::Node.new "modify"
+ modified << elt.to_xml_node(changeset_cache, user_display_name_cache)
+ 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
+ # find any bounding box
+ if params['bbox']
+ bbox = BoundingBox.from_bbox_params(params)
+ end
+
+ # create the conditions that the user asked for. some or all of
+ # these may be nil.
+ changesets = Changeset.all
+ changesets = conditions_bbox(changesets, bbox)
+ changesets = conditions_user(changesets, params['user'], params['display_name'])
+ changesets = conditions_time(changesets, params['time'])
+ changesets = conditions_open(changesets, params['open'])
+ changesets = conditions_closed(changesets, params['closed'])
+ changesets = conditions_ids(changesets, params['changesets'])
+
+ # create the results document
+ results = OSM::API.new.get_xml_doc
+
+ # add all matching changesets to the XML results document
+ changesets.order("created_at DESC").limit(100).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 :text => "", :status => :bad_request
+ end
+ end
+
+ ##
+ # list edits (open changesets) in reverse chronological order
+ def list
+ if request.format == :atom and params[:max_id]
+ redirect_to params.merge({ :max_id => nil }), :status => :moved_permanently
+ return
+ end
+
+ if params[:display_name]
+ user = User.find_by_display_name(params[:display_name])
+ if !user || !user.active?
+ render_unknown_user params[:display_name]
+ return
+ end
+ end
+
+ if (params[:friends] || params[:nearby]) && !@user && request.format == :html
+ require_user
+ return
+ end
+
+ if request.format == :html and !params[:list]
+ require_oauth
+ render :action => :history, :layout => map_layout
+ else
+ changesets = conditions_nonempty(Changeset.all)
+
+ if params[:display_name]
+ if user.data_public? or user == @user
+ changesets = changesets.where(:user_id => user.id)
+ else
+ changesets = changesets.where("false")
+ end
+ elsif params[:bbox]
+ changesets = conditions_bbox(changesets, BoundingBox.from_bbox_params(params))
+ elsif params[:friends] && @user
+ changesets = changesets.where(:user_id => @user.friend_users.public)
+ elsif params[:nearby] && @user
+ changesets = changesets.where(:user_id => @user.nearby)
+ end
+
+ if params[:max_id]
+ changesets = changesets.where("changesets.id <= ?", params[:max_id])
+ end
+
+ @edits = changesets.order("changesets.id DESC").limit(20).preload(:user, :changeset_tags)
+
+ render :action => :list, :layout => false
+ end
+ end
+
+ ##
+ # list edits as an atom feed
+ def feed
+ list
+ end
+
+private
+ #------------------------------------------------------------
+ # utility functions below.
+ #------------------------------------------------------------
+
+ ##
+ # if a bounding box was specified do some sanity checks.
+ # restrict changesets to those enclosed by a bounding box
+ # we need to return both the changesets and the bounding box
+ def conditions_bbox(changesets, bbox)
+ if bbox
+ bbox.check_boundaries
+ bbox = bbox.to_scaled
+ return changesets.where("min_lon < ? and max_lon > ? and min_lat < ? and max_lat > ?",
+ bbox.max_lon.to_i, bbox.min_lon.to_i,
+ bbox.max_lat.to_i, bbox.min_lat.to_i)
+ else
+ return changesets
+ end
+ end
+
+ ##
+ # restrict changesets to those by a particular user
+ def conditions_user(changesets, user, name)
+ unless user.nil? and name.nil?
+ # shouldn't provide both name and UID
+ raise OSM::APIBadUserInput.new("provide either the user ID or display name, but not both") if user and name
+
+ # use either the name or the UID to find the user which we're selecting on.
+ u = if name.nil?
+ # user input checking, we don't have any UIDs < 1
+ raise OSM::APIBadUserInput.new("invalid user ID") if user.to_i < 1
+ u = User.find(user.to_i)
+ else
+ u = User.find_by_display_name(name)
+ end
+
+ # make sure we found a user
+ raise OSM::APINotFoundError.new if u.nil?
+
+ # should be able to get changesets of public users only, or
+ # our own changesets regardless of public-ness.
+ unless u.data_public?
+ # get optional user auth stuff so that users can see their own
+ # changesets if they're non-public
+ setup_user_auth
+
+ raise OSM::APINotFoundError if @user.nil? or @user.id != u.id
+ end
+ return changesets.where(:user_id => u.id)
+ else
+ return changesets
+ end
+ end
+
+ ##
+ # restrict changes to those closed during a particular time period
+ def conditions_time(changesets, time)
+ unless time.nil?
+ # if there is a range, i.e: comma separated, then the first is
+ # low, second is high - same as with bounding boxes.
+ if time.count(',') == 1
+ # check that we actually have 2 elements in the array
+ times = time.split(/,/)
+ raise OSM::APIBadUserInput.new("bad time range") if times.size != 2
+
+ from, to = times.collect { |t| DateTime.parse(t) }
+ return changesets.where("closed_at >= ? and created_at <= ?", from, to)
+ else
+ # if there is no comma, assume its a lower limit on time
+ return changesets.where("closed_at >= ?", DateTime.parse(time))
+ end
+ else
+ return changesets
+ end
+ # stupid DateTime seems to throw both of these for bad parsing, so
+ # we have to catch both and ensure the correct code path is taken.
+ rescue ArgumentError => ex
+ raise OSM::APIBadUserInput.new(ex.message.to_s)
+ rescue RuntimeError => ex
+ raise OSM::APIBadUserInput.new(ex.message.to_s)
+ end
+
+ ##
+ # return changesets which are open (haven't been closed yet)
+ # we do this by seeing if the 'closed at' time is in the future. Also if we've
+ # hit the maximum number of changes then it counts as no longer open.
+ # if parameter 'open' is nill then open and closed changesets are returned
+ def conditions_open(changesets, open)
+ if open.nil?
+ return changesets
+ else
+ return changesets.where("closed_at >= ? and num_changes <= ?",
+ Time.now.getutc, Changeset::MAX_ELEMENTS)
+ end
+ end
+
+ ##
+ # query changesets which are closed
+ # ('closed at' time has passed or changes limit is hit)
+ def conditions_closed(changesets, closed)
+ if closed.nil?
+ return changesets
+ else
+ return changesets.where("closed_at < ? or num_changes > ?",
+ Time.now.getutc, Changeset::MAX_ELEMENTS)
+ end
+ end
+
+ ##
+ # query changesets by a list of ids
+ # (either specified as array or comma-separated string)
+ def conditions_ids(changesets, ids)
+ if ids.nil?
+ return changesets
+ elsif ids.empty?
+ raise OSM::APIBadUserInput.new("No changesets were given to search for")
+ else
+ ids = ids.split(',').collect { |n| n.to_i }
+ return changesets.where(:id => ids)
+ end
+ end
+
+ ##
+ # eliminate empty changesets (where the bbox has not been set)
+ # this should be applied to all changeset list displays
+ def conditions_nonempty(changesets)
+ return changesets.where("num_changes > 0")
+ end
+