- # Helper methods for checking consistency
- include ConsistencyValidations
-
- # Create a changeset from XML.
- def create
- assert_method :put
-
- cs = Changeset.from_xml(request.raw_post, true)
-
- # Assume that Changeset.from_xml has thrown an exception if there is an error parsing the xml
- cs.user = current_user
- cs.save_with_tags!
-
- # Subscribe user to changeset comments
- cs.subscribers << current_user
-
- render :plain => cs.id.to_s
- end
-
- ##
- # Return XML giving the basic info about the changeset. Does not
- # return anything about the nodes, ways and relations in the changeset.
- def read
- changeset = Changeset.find(params[:id])
-
- render :xml => changeset.to_xml(params[:include_discussion].presence).to_s
- end
-
- ##
- # marks a changeset as closed. this may be called multiple times
- # on the same changeset, so is idempotent.
- def close
- assert_method :put
-
- changeset = Changeset.find(params[:id])
- check_changeset_consistency(changeset, current_user)
-
- # to close the changeset, we'll just set its closed_at time to
- # now. this might not be enough if there are concurrency issues,
- # but we'll have to wait and see.
- changeset.set_closed_time_now
-
- changeset.save!
- head :ok
- 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 expand_bbox
- # only allow POST requests, because although this method is
- # idempotent, there is no "document" to PUT really...
- assert_method :post
-
- cs = Changeset.find(params[:id])
- check_changeset_consistency(cs, current_user)
-
- # keep an array of lons and lats
- lon = []
- lat = []
-
- # 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, :options => XML::Parser::Options::NOERROR).parse
- doc.find("//osm/node").each do |n|
- lon << n["lon"].to_f * GeoRecord::SCALE
- lat << n["lat"].to_f * GeoRecord::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 = lon.min
- cs.min_lat = lat.min
- cs.max_lon = lon.max
- cs.max_lat = lat.max
-
- # save the larger bounding box and return the changeset, which
- # will include the bigger bounding box.
- cs.save!
- render :xml => cs.to_xml.to_s
- 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/wiki/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
- assert_method :post
-
- changeset = Changeset.find(params[:id])
- check_changeset_consistency(changeset, current_user)
-
- diff_reader = DiffReader.new(request.raw_post, changeset)
- Changeset.transaction do
- result = diff_reader.commit
- render :xml => result.to_s
- end
- 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 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)
- elsif elt.visible
- # must be a modify
- modified = XML::Node.new "modify"
- modified << elt.to_xml_node(changeset_cache, user_display_name_cache)
- else
- # 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)
- end
- end
-
- render :xml => result.to_s
- end
-
- ##
- # query changesets by bounding box, time, user or open/closed status.
- def query
- # find any bounding box
- bbox = BoundingBox.from_bbox_params(params) if params["bbox"]
-
- # 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"])
-
- # sort and limit the changesets
- changesets = changesets.order("created_at DESC").limit(100)
-
- # preload users, tags and comments
- changesets = changesets.preload(:user, :changeset_tags, :comments)
-
- # 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 :xml => results.to_s
- 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