Make sure the recorded first point for a trace really is the first
[rails.git] / app / models / relation.rb
1 class Relation < ActiveRecord::Base
2   require 'xml/libxml'
3   
4   belongs_to :user
5
6   has_many :relation_members, :foreign_key => 'id'
7   has_many :relation_tags, :foreign_key => 'id'
8
9   has_many :old_relations, :foreign_key => 'id', :order => 'version'
10
11   set_table_name 'current_relations'
12
13   def self.from_xml(xml, create=false)
14     begin
15       p = XML::Parser.new
16       p.string = xml
17       doc = p.parse
18
19       relation = Relation.new
20
21       doc.find('//osm/relation').each do |pt|
22         if !create and pt['id'] != '0'
23           relation.id = pt['id'].to_i
24         end
25
26         if create
27           relation.timestamp = Time.now
28           relation.visible = true
29         else
30           if pt['timestamp']
31             relation.timestamp = Time.parse(pt['timestamp'])
32           end
33         end
34
35         pt.find('tag').each do |tag|
36           relation.add_tag_keyval(tag['k'], tag['v'])
37         end
38
39         pt.find('member').each do |member|
40           relation.add_member(member['type'], member['ref'], member['role'])
41         end
42       end
43     rescue
44       relation = nil
45     end
46
47     return relation
48   end
49
50   def to_xml
51     doc = OSM::API.new.get_xml_doc
52     doc.root << to_xml_node()
53     return doc
54   end
55
56   def to_xml_node(user_display_name_cache = nil)
57     el1 = XML::Node.new 'relation'
58     el1['id'] = self.id.to_s
59     el1['visible'] = self.visible.to_s
60     el1['timestamp'] = self.timestamp.xmlschema
61
62     user_display_name_cache = {} if user_display_name_cache.nil?
63     
64     if user_display_name_cache and user_display_name_cache.key?(self.user_id)
65       # use the cache if available
66     elsif self.user.data_public?
67       user_display_name_cache[self.user_id] = self.user.display_name
68     else
69       user_display_name_cache[self.user_id] = nil
70     end
71
72     el1['user'] = user_display_name_cache[self.user_id] unless user_display_name_cache[self.user_id].nil?
73
74     self.relation_members.each do |member|
75       p=0
76       #if visible_members
77       #  # if there is a list of visible members then use that to weed out deleted segments
78       #  if visible_members[member.member_type][member.member_id]
79       #    p=1
80       #  end
81       #else
82         # otherwise, manually go to the db to check things
83         if member.member.visible?
84           p=1
85         end
86       #end
87       if p
88         e = XML::Node.new 'member'
89         e['type'] = member.member_type
90         e['ref'] = member.member_id.to_s 
91         e['role'] = member.member_role
92         el1 << e
93        end
94     end
95
96     self.relation_tags.each do |tag|
97       e = XML::Node.new 'tag'
98       e['k'] = tag.k
99       e['v'] = tag.v
100       el1 << e
101     end
102     return el1
103   end 
104
105     
106   # collect relationships. currently done in one big block at the end;
107   # may need to move this upwards if people want automatic completion of
108   # relationships, i.e. deliver referenced objects like we do with ways... 
109   # FIXME: rip out the fucking SQL
110   def self.find_for_nodes_and_ways(node_ids, way_ids)
111     relations = []
112
113     if node_ids.length > 0
114       relations += Relation.find_by_sql("select e.* from current_relations e,current_relation_members em where " +
115             "e.visible=1 and " +
116             "em.id = e.id and em.member_type='node' and em.member_id in (#{node_ids.join(',')})")
117     end
118     if way_ids.length > 0
119       relations += Relation.find_by_sql("select e.* from current_relations e,current_relation_members em where " +
120             "e.visible=1 and " +
121             "em.id = e.id and em.member_type='way' and em.member_id in (#{way_ids.join(',')})")
122     end
123
124     relations # if you don't do this then it returns nil and not []
125   end
126
127
128   # FIXME is this really needed?
129   def members
130     unless @members
131       @members = Array.new
132       self.relation_members.each do |member|
133         @members += [[member.member_type,member.member_id,member.member_role]]
134       end
135     end
136     @members
137   end
138
139   def tags
140     unless @tags
141       @tags = Hash.new
142       self.relation_tags.each do |tag|
143         @tags[tag.k] = tag.v
144       end
145     end
146     @tags
147   end
148
149   def members=(m)
150     @members = m
151   end
152
153   def tags=(t)
154     @tags = t
155   end
156
157   def add_member(type,id,role)
158     @members = Array.new unless @members
159     @members += [[type,id,role]]
160   end
161
162   def add_tag_keyval(k, v)
163     @tags = Hash.new unless @tags
164     @tags[k] = v
165   end
166
167   def save_with_history!
168     Relation.transaction do
169       t = Time.now
170       self.timestamp = t
171       self.save!
172
173       tags = self.tags
174
175       RelationTag.delete_all(['id = ?', self.id])
176
177       tags.each do |k,v|
178         tag = RelationTag.new
179         tag.k = k
180         tag.v = v
181         tag.id = self.id
182         tag.save!
183       end
184
185       members = self.members
186
187       RelationMember.delete_all(['id = ?', self.id])
188
189       members.each do |n|
190         mem = RelationMember.new
191         mem.id = self.id
192         mem.member_type = n[0];
193         mem.member_id = n[1];
194         mem.member_role = n[2];
195         mem.save!
196       end
197
198       old_relation = OldRelation.from_relation(self)
199       old_relation.timestamp = t
200       old_relation.save_with_dependencies!
201     end
202   end
203
204   def preconditions_ok?
205     self.members.each do |m|
206       if (m[0] == "node")
207         n = Node.find(:first, :conditions => ["id = ?", m[1]])
208         unless n and n.visible 
209           return false
210         end
211       elsif (m[0] == "way")
212         w = Way.find(:first, :conditions => ["id = ?", m[1]])
213         unless w and w.visible and w.preconditions_ok?
214           return false
215         end
216       elsif (m[0] == "relation")
217         e = Relation.find(:first, :conditions => ["id = ?", m[1]])
218         unless e and e.visible and e.preconditions_ok?
219           return false
220         end
221       else
222         return false
223       end
224     end
225     return true
226   rescue
227     return false
228   end
229
230 end