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   # FIXME is this really needed?
 106   def members
 107     unless @members
 108         @members = Array.new
 109         self.relation_members.each do |member|
 110             @members += [[member.member_type,member.member_id,member.member_role]]
 111         end
 112     end
 113     @members
 114   end
 115
 116   def tags
 117     unless @tags
 118         @tags = Hash.new
 119         self.relation_tags.each do |tag|
 120             @tags[tag.k] = tag.v
 121         end
 122     end
 123     @tags
 124   end
 125
 126   def members=(m)
 127     @members = m
 128   end
 129
 130   def tags=(t)
 131     @tags = t
 132   end
 133
 134   def add_member(type,id,role)
 135     @members = Array.new unless @members
 136     @members += [[type,id,role]]
 137   end
 138
 139   def add_tag_keyval(k, v)
 140     @tags = Hash.new unless @tags
 141     @tags[k] = v
 142   end
 143
 144   def save_with_history!
 145     Relation.transaction do
 146       t = Time.now
 147       self.timestamp = t
 148       self.save!
 149
 150       tags = self.tags
 151
 152       RelationTag.delete_all(['id = ?', self.id])
 153
 154       tags.each do |k,v|
 155         tag = RelationTag.new
 156         tag.k = k
 157         tag.v = v
 158         tag.id = self.id
 159         tag.save!
 160       end
 161
 162       members = self.members
 163
 164       RelationMember.delete_all(['id = ?', self.id])
 165
 166       members.each do |n|
 167         mem = RelationMember.new
 168         mem.id = self.id
 169         mem.member_type = n[0];
 170         mem.member_id = n[1];
 171         mem.member_role = n[2];
 172         mem.save!
 173       end
 174
 175       old_relation = OldRelation.from_relation(self)
 176       old_relation.timestamp = t
 177       old_relation.save_with_dependencies!
 178     end
 179   end
 180
 181   def preconditions_ok?
 182     self.members.each do |m|
 183       if (m[0] == "node")
 184         n = Node.find(:first, :conditions => ["id = ?", m[1]])
 185         unless n and n.visible
 186           return false
 187         end
 188       elsif (m[0] == "way")
 189         w = Way.find(:first, :conditions => ["id = ?", m[1]])
 190         unless w and w.visible and w.preconditions_ok?
 191           return false
 192         end
 193       elsif (m[0] == "relation")
 194         e = Relation.find(:first, :conditions => ["id = ?", m[1]])
 195         unless e and e.visible and e.preconditions_ok?
 196           return false
 197         end
 198       else
 199         return false
 200       end
 201     end
 202     return true
 203   rescue
 204     return false
 205   end
 206
 207 end