1 class Relation < ActiveRecord::Base
4 include ConsistencyValidations
7 self.table_name = "current_relations"
11 has_many :old_relations, :order => 'version'
13 has_many :relation_members, :order => 'sequence_id'
14 has_many :relation_tags
16 has_many :containing_relation_members, :class_name => "RelationMember", :as => :member
17 has_many :containing_relations, :class_name => "Relation", :through => :containing_relation_members, :source => :relation, :extend => ObjectFinder
19 validates_presence_of :id, :on => :update
20 validates_presence_of :timestamp,:version, :changeset_id
21 validates_uniqueness_of :id
22 validates_inclusion_of :visible, :in => [ true, false ]
23 validates_numericality_of :id, :on => :update, :integer_only => true
24 validates_numericality_of :changeset_id, :version, :integer_only => true
25 validates_associated :changeset
27 scope :visible, where(:visible => true)
28 scope :invisible, where(:visible => false)
29 scope :nodes, lambda { |*ids| joins(:relation_members).where(:current_relation_members => { :member_type => "Node", :member_id => ids }) }
30 scope :ways, lambda { |*ids| joins(:relation_members).where(:current_relation_members => { :member_type => "Way", :member_id => ids }) }
31 scope :relations, lambda { |*ids| joins(:relation_members).where(:current_relation_members => { :member_type => "Relation", :member_id => ids }) }
33 TYPES = ["node", "way", "relation"]
35 def self.from_xml(xml, create=false)
37 p = XML::Parser.string(xml)
40 doc.find('//osm/relation').each do |pt|
41 return Relation.from_xml_node(pt, create)
43 raise OSM::APIBadXMLError.new("node", xml, "XML doesn't contain an osm/relation element.")
44 rescue LibXML::XML::Error, ArgumentError => ex
45 raise OSM::APIBadXMLError.new("relation", xml, ex.message)
49 def self.from_xml_node(pt, create=false)
50 relation = Relation.new
52 raise OSM::APIBadXMLError.new("relation", pt, "Version is required when updating") unless create or not pt['version'].nil?
53 relation.version = pt['version']
54 raise OSM::APIBadXMLError.new("relation", pt, "Changeset id is missing") if pt['changeset'].nil?
55 relation.changeset_id = pt['changeset']
58 raise OSM::APIBadXMLError.new("relation", pt, "ID is required when updating") if pt['id'].nil?
59 relation.id = pt['id'].to_i
60 # .to_i will return 0 if there is no number that can be parsed.
61 # We want to make sure that there is no id with zero anyway
62 raise OSM::APIBadUserInput.new("ID of relation cannot be zero when updating.") if relation.id == 0
65 # We don't care about the timestamp nor the visibility as these are either
66 # set explicitly or implicit in the action. The visibility is set to true,
67 # and manually set to false before the actual delete.
68 relation.visible = true
71 relation.tags = Hash.new
73 # Add in any tags from the XML
74 pt.find('tag').each do |tag|
75 raise OSM::APIBadXMLError.new("relation", pt, "tag is missing key") if tag['k'].nil?
76 raise OSM::APIBadXMLError.new("relation", pt, "tag is missing value") if tag['v'].nil?
77 relation.add_tag_keyval(tag['k'], tag['v'])
80 # need to initialise the relation members array explicitly, as if this
81 # isn't done for a new relation then @members attribute will be nil,
82 # and the members will be loaded from the database instead of being
84 relation.members = Array.new
86 pt.find('member').each do |member|
88 logger.debug "each member"
89 raise OSM::APIBadXMLError.new("relation", pt, "The #{member['type']} is not allowed only, #{TYPES.inspect} allowed") unless TYPES.include? member['type']
90 logger.debug "after raise"
91 #member_ref = member['ref']
93 member['role'] ||= "" # Allow the upload to not include this, in which case we default to an empty string.
94 logger.debug member['role']
95 relation.add_member(member['type'].classify, member['ref'], member['role'])
97 raise OSM::APIBadUserInput.new("Some bad xml in relation") if relation.nil?
103 doc = OSM::API.new.get_xml_doc
104 doc.root << to_xml_node()
108 def to_xml_node(visible_members = nil, changeset_cache = {}, user_display_name_cache = {})
109 el1 = XML::Node.new 'relation'
110 el1['id'] = self.id.to_s
111 el1['visible'] = self.visible.to_s
112 el1['timestamp'] = self.timestamp.xmlschema
113 el1['version'] = self.version.to_s
114 el1['changeset'] = self.changeset_id.to_s
116 if changeset_cache.key?(self.changeset_id)
117 # use the cache if available
119 changeset_cache[self.changeset_id] = self.changeset.user_id
122 user_id = changeset_cache[self.changeset_id]
124 if user_display_name_cache.key?(user_id)
125 # use the cache if available
126 elsif self.changeset.user.data_public?
127 user_display_name_cache[user_id] = self.changeset.user.display_name
129 user_display_name_cache[user_id] = nil
132 if not user_display_name_cache[user_id].nil?
133 el1['user'] = user_display_name_cache[user_id]
134 el1['uid'] = user_id.to_s
137 self.relation_members.each do |member|
138 e = XML::Node.new 'member'
139 e['type'] = member.member_type.downcase
140 e['ref'] = member.member_id.to_s
141 e['role'] = member.member_role
145 self.relation_tags.each do |tag|
146 e = XML::Node.new 'tag'
154 # FIXME is this really needed?
156 @members ||= self.relation_members.map do |member|
157 [member.member_type, member.member_id, member.member_role]
164 self.relation_tags.each do |tag|
179 def add_member(type, id, role)
181 @members << [type, id.to_i, role]
184 def add_tag_keyval(k, v)
185 @tags = Hash.new unless @tags
187 # duplicate tags are now forbidden, so we can't allow values
188 # in the hash to be overwritten.
189 raise OSM::APIDuplicateTagsError.new("relation", self.id, k) if @tags.include? k
195 # updates the changeset bounding box to contain the bounding box of
196 # the element with given +type+ and +id+. this only works with nodes
197 # and ways at the moment, as they're the only elements to respond to
199 def update_changeset_element(type, id)
200 element = Kernel.const_get(type.capitalize).find(id)
201 changeset.update_bbox! element.bbox
204 def delete_with_history!(new_relation, user)
206 raise OSM::APIAlreadyDeletedError.new("relation", new_relation.id)
209 # need to start the transaction here, so that the database can
210 # provide repeatable reads for the used-by checks. this means it
211 # shouldn't be possible to get race conditions.
212 Relation.transaction do
214 check_consistency(self, new_relation, user)
215 # This will check to see if this relation is used by another relation
216 rel = RelationMember.joins(:relation).where("visible = ? AND member_type = 'Relation' and member_id = ? ", true, self.id).first
217 raise OSM::APIPreconditionFailedError.new("The relation #{new_relation.id} is used in relation #{rel.relation.id}.") unless rel.nil?
219 self.changeset_id = new_relation.changeset_id
227 def update_from(new_relation, user)
228 Relation.transaction do
230 check_consistency(self, new_relation, user)
231 unless new_relation.preconditions_ok?(self.members)
232 raise OSM::APIPreconditionFailedError.new("Cannot update relation #{self.id}: data or member data is invalid.")
234 self.changeset_id = new_relation.changeset_id
235 self.changeset = new_relation.changeset
236 self.tags = new_relation.tags
237 self.members = new_relation.members
243 def create_with_history(user)
244 check_create_consistency(self, user)
245 unless self.preconditions_ok?
246 raise OSM::APIPreconditionFailedError.new("Cannot create relation: data or member data is invalid.")
253 def preconditions_ok?(good_members = [])
254 # These are hastables that store an id in the index of all
255 # the nodes/way/relations that have already been added.
256 # If the member is valid and visible then we add it to the
257 # relevant hash table, with the value true as a cache.
258 # Thus if you have nodes with the ids of 50 and 1 already in the
259 # relation, then the hash table nodes would contain:
260 # => {50=>true, 1=>true}
261 elements = { :node => Hash.new, :way => Hash.new, :relation => Hash.new }
263 # pre-set all existing members to good
264 good_members.each { |m| elements[m[0].downcase.to_sym][m[1]] = true }
266 self.members.each do |m|
267 # find the hash for the element type or die
268 hash = elements[m[0].downcase.to_sym] or return false
269 # unless its in the cache already
270 unless hash.key? m[1]
271 # use reflection to look up the appropriate class
272 model = Kernel.const_get(m[0].capitalize)
273 # get the element with that ID
274 element = model.where(:id => m[1]).first
276 # and check that it is OK to use.
277 unless element and element.visible? and element.preconditions_ok?
278 raise OSM::APIPreconditionFailedError.new("Relation with id #{self.id} cannot be saved due to #{m[0]} with id #{m[1]}")
287 # Temporary method to match interface to nodes
293 # if any members are referenced by placeholder IDs (i.e: negative) then
294 # this calling this method will fix them using the map from placeholders
296 def fix_placeholders!(id_map, placeholder_id = nil)
297 self.members.map! do |type, id, role|
300 new_id = id_map[type.downcase.to_sym][old_id]
301 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?
311 def save_with_history!
312 Relation.transaction do
313 # have to be a little bit clever here - to detect if any tags
314 # changed then we have to monitor their before and after state.
322 tags = self.tags.clone
323 self.relation_tags.each do |old_tag|
325 # if we can match the tags we currently have to the list
326 # of old tags, then we never set the tags_changed flag. but
327 # if any are different then set the flag and do the DB
330 tags_changed |= (old_tag.v != tags[key])
332 # remove from the map, so that we can expect an empty map
333 # at the end if there are no new tags
337 # this means a tag was deleted
341 # if there are left-over tags then they are new and will have to
343 tags_changed |= (not tags.empty?)
344 RelationTag.delete_all(:relation_id => self.id)
345 self.tags.each do |k,v|
346 tag = RelationTag.new
347 tag.relation_id = self.id
353 # same pattern as before, but this time we're collecting the
354 # changed members in an array, as the bounding box updates for
355 # elements are per-element, not blanked on/off like for tags.
356 changed_members = Array.new
357 members = self.members.clone
358 self.relation_members.each do |old_member|
359 key = [old_member.member_type, old_member.member_id, old_member.member_role]
360 i = members.index key
362 changed_members << key
367 # any remaining members must be new additions
368 changed_members += members
370 # update the members. first delete all the old members, as the new
371 # members may be in a different order and i don't feel like implementing
372 # a longest common subsequence algorithm to optimise this.
373 members = self.members
374 RelationMember.delete_all(:relation_id => self.id)
375 members.each_with_index do |m,i|
376 mem = RelationMember.new
377 mem.relation_id = self.id
379 mem.member_type = m[0]
381 mem.member_role = m[2]
385 old_relation = OldRelation.from_relation(self)
386 old_relation.timestamp = t
387 old_relation.save_with_dependencies!
389 # update the bbox of the changeset and save it too.
390 # discussion on the mailing list gave the following definition for
391 # the bounding box update procedure of a relation:
393 # adding or removing nodes or ways from a relation causes them to be
394 # added to the changeset bounding box. adding a relation member or
395 # changing tag values causes all node and way members to be added to the
396 # bounding box. this is similar to how the map call does things and is
397 # reasonable on the assumption that adding or removing members doesn't
398 # materially change the rest of the relation.
400 changed_members.collect { |id,type| type == "relation" }.
401 inject(false) { |b,s| b or s }
403 update_members = if tags_changed or any_relations
404 # add all non-relation bounding boxes to the changeset
405 # FIXME: check for tag changes along with element deletions and
406 # make sure that the deleted element's bounding box is hit.
411 update_members.each do |type, id, role|
412 if type != "Relation"
413 update_changeset_element(type, id)
417 # tell the changeset we updated one element only
418 changeset.add_changes! 1
420 # save the (maybe updated) changeset bounding box