1 class Relation < ActiveRecord::Base
4 include ConsistencyValidations
8 self.table_name = "current_relations"
12 has_many :old_relations, -> { order(:version) }
14 has_many :relation_members, -> { order(:sequence_id) }
15 has_many :relation_tags
17 has_many :containing_relation_members, :class_name => "RelationMember", :as => :member
18 has_many :containing_relations, :class_name => "Relation", :through => :containing_relation_members, :source => :relation, :extend => ObjectFinder
20 validates_presence_of :id, :on => :update
21 validates_presence_of :timestamp,:version, :changeset_id
22 validates_uniqueness_of :id
23 validates_inclusion_of :visible, :in => [ true, false ]
24 validates_numericality_of :id, :on => :update, :integer_only => true
25 validates_numericality_of :changeset_id, :version, :integer_only => true
26 validates_associated :changeset
28 scope :visible, -> { where(:visible => true) }
29 scope :invisible, -> { where(:visible => false) }
30 scope :nodes, ->(*ids) { joins(:relation_members).where(:current_relation_members => { :member_type => "Node", :member_id => ids.flatten }) }
31 scope :ways, ->(*ids) { joins(:relation_members).where(:current_relation_members => { :member_type => "Way", :member_id => ids.flatten }) }
32 scope :relations, ->(*ids) { joins(:relation_members).where(:current_relation_members => { :member_type => "Relation", :member_id => ids.flatten }) }
34 TYPES = ["node", "way", "relation"]
36 def self.from_xml(xml, create=false)
38 p = XML::Parser.string(xml)
41 doc.find('//osm/relation').each do |pt|
42 return Relation.from_xml_node(pt, create)
44 raise OSM::APIBadXMLError.new("node", xml, "XML doesn't contain an osm/relation element.")
45 rescue LibXML::XML::Error, ArgumentError => ex
46 raise OSM::APIBadXMLError.new("relation", xml, ex.message)
50 def self.from_xml_node(pt, create=false)
51 relation = Relation.new
53 raise OSM::APIBadXMLError.new("relation", pt, "Version is required when updating") unless create or not pt['version'].nil?
54 relation.version = pt['version']
55 raise OSM::APIBadXMLError.new("relation", pt, "Changeset id is missing") if pt['changeset'].nil?
56 relation.changeset_id = pt['changeset']
59 raise OSM::APIBadXMLError.new("relation", pt, "ID is required when updating") if pt['id'].nil?
60 relation.id = pt['id'].to_i
61 # .to_i will return 0 if there is no number that can be parsed.
62 # We want to make sure that there is no id with zero anyway
63 raise OSM::APIBadUserInput.new("ID of relation cannot be zero when updating.") if relation.id == 0
66 # We don't care about the timestamp nor the visibility as these are either
67 # set explicitly or implicit in the action. The visibility is set to true,
68 # and manually set to false before the actual delete.
69 relation.visible = true
72 relation.tags = Hash.new
74 # Add in any tags from the XML
75 pt.find('tag').each do |tag|
76 raise OSM::APIBadXMLError.new("relation", pt, "tag is missing key") if tag['k'].nil?
77 raise OSM::APIBadXMLError.new("relation", pt, "tag is missing value") if tag['v'].nil?
78 relation.add_tag_keyval(tag['k'], tag['v'])
81 # need to initialise the relation members array explicitly, as if this
82 # isn't done for a new relation then @members attribute will be nil,
83 # and the members will be loaded from the database instead of being
85 relation.members = Array.new
87 pt.find('member').each do |member|
89 logger.debug "each member"
90 raise OSM::APIBadXMLError.new("relation", pt, "The #{member['type']} is not allowed only, #{TYPES.inspect} allowed") unless TYPES.include? member['type']
91 logger.debug "after raise"
92 #member_ref = member['ref']
94 member['role'] ||= "" # Allow the upload to not include this, in which case we default to an empty string.
95 logger.debug member['role']
96 relation.add_member(member['type'].classify, member['ref'], member['role'])
98 raise OSM::APIBadUserInput.new("Some bad xml in relation") if relation.nil?
104 doc = OSM::API.new.get_xml_doc
105 doc.root << to_xml_node()
109 def to_xml_node(visible_members = nil, changeset_cache = {}, user_display_name_cache = {})
110 el1 = XML::Node.new 'relation'
111 el1['id'] = self.id.to_s
112 add_metadata_to_xml_node(el1, self, changeset_cache, user_display_name_cache)
114 self.relation_members.each do |member|
117 # if there is a list of visible members then use that to weed out deleted segments
118 if visible_members[member.member_type][member.member_id]
122 # otherwise, manually go to the db to check things
123 if member.member.visible?
128 e = XML::Node.new 'member'
129 e['type'] = member.member_type.downcase
130 e['ref'] = member.member_id.to_s
131 e['role'] = member.member_role
136 self.relation_tags.each do |tag|
137 e = XML::Node.new 'tag'
145 # FIXME is this really needed?
147 @members ||= self.relation_members.map do |member|
148 [member.member_type, member.member_id, member.member_role]
155 self.relation_tags.each do |tag|
170 def add_member(type, id, role)
172 @members << [type, id.to_i, role]
175 def add_tag_keyval(k, v)
176 @tags = Hash.new unless @tags
178 # duplicate tags are now forbidden, so we can't allow values
179 # in the hash to be overwritten.
180 raise OSM::APIDuplicateTagsError.new("relation", self.id, k) if @tags.include? k
186 # updates the changeset bounding box to contain the bounding box of
187 # the element with given +type+ and +id+. this only works with nodes
188 # and ways at the moment, as they're the only elements to respond to
190 def update_changeset_element(type, id)
191 element = Kernel.const_get(type.capitalize).find(id)
192 changeset.update_bbox! element.bbox
195 def delete_with_history!(new_relation, user)
197 raise OSM::APIAlreadyDeletedError.new("relation", new_relation.id)
200 # need to start the transaction here, so that the database can
201 # provide repeatable reads for the used-by checks. this means it
202 # shouldn't be possible to get race conditions.
203 Relation.transaction do
205 check_consistency(self, new_relation, user)
206 # This will check to see if this relation is used by another relation
207 rel = RelationMember.joins(:relation).where("visible = ? AND member_type = 'Relation' and member_id = ? ", true, self.id).first
208 raise OSM::APIPreconditionFailedError.new("The relation #{new_relation.id} is used in relation #{rel.relation.id}.") unless rel.nil?
210 self.changeset_id = new_relation.changeset_id
218 def update_from(new_relation, user)
219 Relation.transaction do
221 check_consistency(self, new_relation, user)
222 unless new_relation.preconditions_ok?(self.members)
223 raise OSM::APIPreconditionFailedError.new("Cannot update relation #{self.id}: data or member data is invalid.")
225 self.changeset_id = new_relation.changeset_id
226 self.changeset = new_relation.changeset
227 self.tags = new_relation.tags
228 self.members = new_relation.members
234 def create_with_history(user)
235 check_create_consistency(self, user)
236 unless self.preconditions_ok?
237 raise OSM::APIPreconditionFailedError.new("Cannot create relation: data or member data is invalid.")
244 def preconditions_ok?(good_members = [])
245 # These are hastables that store an id in the index of all
246 # the nodes/way/relations that have already been added.
247 # If the member is valid and visible then we add it to the
248 # relevant hash table, with the value true as a cache.
249 # Thus if you have nodes with the ids of 50 and 1 already in the
250 # relation, then the hash table nodes would contain:
251 # => {50=>true, 1=>true}
252 elements = { :node => Hash.new, :way => Hash.new, :relation => Hash.new }
254 # pre-set all existing members to good
255 good_members.each { |m| elements[m[0].downcase.to_sym][m[1]] = true }
257 self.members.each do |m|
258 # find the hash for the element type or die
259 hash = elements[m[0].downcase.to_sym] or return false
260 # unless its in the cache already
261 unless hash.key? m[1]
262 # use reflection to look up the appropriate class
263 model = Kernel.const_get(m[0].capitalize)
264 # get the element with that ID
265 element = model.where(:id => m[1]).first
267 # and check that it is OK to use.
268 unless element and element.visible? and element.preconditions_ok?
269 raise OSM::APIPreconditionFailedError.new("Relation with id #{self.id} cannot be saved due to #{m[0]} with id #{m[1]}")
278 # Temporary method to match interface to nodes
284 # if any members are referenced by placeholder IDs (i.e: negative) then
285 # this calling this method will fix them using the map from placeholders
287 def fix_placeholders!(id_map, placeholder_id = nil)
288 self.members.map! do |type, id, role|
291 new_id = id_map[type.downcase.to_sym][old_id]
292 raise OSM::APIBadUserInput.new("Placeholder #{type} not found for reference #{old_id} in relation #{self.id.nil? ? placeholder_id : self.id}.") if new_id.nil?
302 def save_with_history!
303 Relation.transaction do
304 # have to be a little bit clever here - to detect if any tags
305 # changed then we have to monitor their before and after state.
313 tags = self.tags.clone
314 self.relation_tags.each do |old_tag|
316 # if we can match the tags we currently have to the list
317 # of old tags, then we never set the tags_changed flag. but
318 # if any are different then set the flag and do the DB
321 tags_changed |= (old_tag.v != tags[key])
323 # remove from the map, so that we can expect an empty map
324 # at the end if there are no new tags
328 # this means a tag was deleted
332 # if there are left-over tags then they are new and will have to
334 tags_changed |= (not tags.empty?)
335 RelationTag.delete_all(:relation_id => self.id)
336 self.tags.each do |k,v|
337 tag = RelationTag.new
338 tag.relation_id = self.id
344 # same pattern as before, but this time we're collecting the
345 # changed members in an array, as the bounding box updates for
346 # elements are per-element, not blanked on/off like for tags.
347 changed_members = Array.new
348 members = self.members.clone
349 self.relation_members.each do |old_member|
350 key = [old_member.member_type, old_member.member_id, old_member.member_role]
351 i = members.index key
353 changed_members << key
358 # any remaining members must be new additions
359 changed_members += members
361 # update the members. first delete all the old members, as the new
362 # members may be in a different order and i don't feel like implementing
363 # a longest common subsequence algorithm to optimise this.
364 members = self.members
365 RelationMember.delete_all(:relation_id => self.id)
366 members.each_with_index do |m,i|
367 mem = RelationMember.new
368 mem.relation_id = self.id
370 mem.member_type = m[0]
372 mem.member_role = m[2]
376 old_relation = OldRelation.from_relation(self)
377 old_relation.timestamp = t
378 old_relation.save_with_dependencies!
380 # update the bbox of the changeset and save it too.
381 # discussion on the mailing list gave the following definition for
382 # the bounding box update procedure of a relation:
384 # adding or removing nodes or ways from a relation causes them to be
385 # added to the changeset bounding box. adding a relation member or
386 # changing tag values causes all node and way members to be added to the
387 # bounding box. this is similar to how the map call does things and is
388 # reasonable on the assumption that adding or removing members doesn't
389 # materially change the rest of the relation.
391 changed_members.collect { |id,type| type == "relation" }.
392 inject(false) { |b,s| b or s }
394 update_members = if tags_changed or any_relations
395 # add all non-relation bounding boxes to the changeset
396 # FIXME: check for tag changes along with element deletions and
397 # make sure that the deleted element's bounding box is hit.
402 update_members.each do |type, id, role|
403 if type != "Relation"
404 update_changeset_element(type, id)
408 # tell the changeset we updated one element only
409 changeset.add_changes! 1
411 # save the (maybe updated) changeset bounding box