class Node < ActiveRecord::Base
+ require 'xml/libxml'
+
+ include GeoRecord
+ include ConsistencyValidations
+
set_table_name 'current_nodes'
- belongs_to :user
+ belongs_to :changeset
+
+ has_many :old_nodes, :foreign_key => :id
+
+ has_many :way_nodes
+ has_many :ways, :through => :way_nodes
+
+ has_many :node_tags, :foreign_key => :id
+
+ has_many :old_way_nodes
+ has_many :ways_via_history, :class_name=> "Way", :through => :old_way_nodes, :source => :way
+
+ has_many :containing_relation_members, :class_name => "RelationMember", :as => :member
+ has_many :containing_relations, :class_name => "Relation", :through => :containing_relation_members, :source => :relation, :extend => ObjectFinder
+
+ validates_presence_of :id, :on => :update
+ validates_presence_of :timestamp,:version, :changeset_id
+ validates_uniqueness_of :id
+ validates_inclusion_of :visible, :in => [ true, false ]
+ validates_numericality_of :latitude, :longitude, :changeset_id, :version, :integer_only => true
+ validates_numericality_of :id, :on => :update, :integer_only => true
+ validate :validate_position
+ validates_associated :changeset
+
+ # Sanity check the latitude and longitude and add an error if it's broken
+ def validate_position
+ errors.add_to_base("Node is not in the world") unless in_world?
+ end
+
+ #
+ # Search for nodes matching tags within bounding_box
+ #
+ # Also adheres to limitations such as within max_number_of_nodes
+ #
+ def self.search(bounding_box, tags = {})
+ min_lon, min_lat, max_lon, max_lat = *bounding_box
+ # @fixme a bit of a hack to search for only visible nodes
+ # couldn't think of another to add to tags condition
+ #conditions_hash = tags.merge({ 'visible' => 1 })
+
+ # using named placeholders http://www.robbyonrails.com/articles/2005/10/21/using-named-placeholders-in-ruby
+ #keys = []
+ #values = {}
+
+ #conditions_hash.each do |key,value|
+ # keys << "#{key} = :#{key}"
+ # values[key.to_sym] = value
+ #end
+ #conditions = keys.join(' AND ')
+
+ find_by_area(min_lat, min_lon, max_lat, max_lon,
+ :conditions => {:visible => true},
+ :limit => APP_CONFIG['max_number_of_nodes']+1)
+ end
+
+ # Read in xml as text and return it's Node object representation
+ def self.from_xml(xml, create=false)
+ begin
+ p = XML::Parser.new
+ p.string = xml
+ doc = p.parse
+
+ doc.find('//osm/node').each do |pt|
+ return Node.from_xml_node(pt, create)
+ end
+ rescue
+ return nil
+ end
+ end
+
+ def self.from_xml_node(pt, create=false)
+ node = Node.new
+
+ node.lat = pt['lat'].to_f
+ node.lon = pt['lon'].to_f
+ node.changeset_id = pt['changeset'].to_i
+
+ return nil unless node.in_world?
+
+ # version must be present unless creating
+ return nil unless create or not pt['version'].nil?
+ node.version = create ? 0 : pt['version'].to_i
+
+ unless create
+ if pt['id'] != '0'
+ node.id = pt['id'].to_i
+ end
+ end
+
+ # visible if it says it is, or as the default if the attribute
+ # is missing.
+ node.visible = pt['visible'].nil? or pt['visible'] == 'true'
+
+ if create
+ node.timestamp = Time.now
+ else
+ if pt['timestamp']
+ node.timestamp = Time.parse(pt['timestamp'])
+ end
+ end
+
+ tags = []
+
+ pt.find('tag').each do |tag|
+ node.add_tag_key_val(tag['k'],tag['v'])
+ end
+
+ return node
+ end
+
+ ##
+ # the bounding box around a node
+ def bbox
+ [ longitude, latitude, longitude, latitude ]
+ end
+
+ def save_with_history!
+ t = Time.now
+ Node.transaction do
+ self.version += 1
+ self.timestamp = t
+ self.save!
+
+ # Create a NodeTag
+ tags = self.tags
+ NodeTag.delete_all(['id = ?', self.id])
+ tags.each do |k,v|
+ tag = NodeTag.new
+ tag.k = k
+ tag.v = v
+ tag.id = self.id
+ tag.save!
+ end
+
+ # Create an OldNode
+ old_node = OldNode.from_node(self)
+ old_node.timestamp = t
+ old_node.save_with_dependencies!
+
+ # tell the changeset we updated one element only
+ changeset.add_changes! 1
+
+ # save the changeset in case of bounding box updates
+ changeset.save!
+ end
+ end
+
+ # Should probably be renamed delete_from to come in line with update
+ def delete_with_history!(new_node, user)
+ if self.visible
+ check_consistency(self, new_node, user)
+ if WayNode.find(:first, :joins => "INNER JOIN current_ways ON current_ways.id = current_way_nodes.id", :conditions => [ "current_ways.visible = ? AND current_way_nodes.node_id = ?", true, self.id ])
+ raise OSM::APIPreconditionFailedError.new
+ elsif RelationMember.find(:first, :joins => "INNER JOIN current_relations ON current_relations.id=current_relation_members.id", :conditions => [ "visible = ? AND member_type='node' and member_id=? ", true, self.id])
+ raise OSM::APIPreconditionFailedError.new
+ else
+ self.changeset_id = new_node.changeset_id
+ self.visible = false
+
+ # update the changeset with the deleted position
+ changeset.update_bbox!(bbox)
+
+ save_with_history!
+ end
+ else
+ raise OSM::APIAlreadyDeletedError.new
+ end
+ end
+
+ def update_from(new_node, user)
+ check_consistency(self, new_node, user)
+
+ # update changeset with *old* position first
+ changeset.update_bbox!(bbox);
+
+ # FIXME logic needs to be double checked
+ self.changeset_id = new_node.changeset_id
+ self.latitude = new_node.latitude
+ self.longitude = new_node.longitude
+ self.tags = new_node.tags
+ self.visible = true
+
+ # update changeset with *new* position
+ changeset.update_bbox!(bbox);
+
+ save_with_history!
+ end
+
+ def create_with_history(user)
+ check_create_consistency(self, user)
+ self.version = 0
+ self.visible = true
+
+ # update the changeset to include the new location
+ changeset.update_bbox!(bbox)
+
+ save_with_history!
+ end
+
+ def to_xml
+ doc = OSM::API.new.get_xml_doc
+ doc.root << to_xml_node()
+ return doc
+ end
+
+ def to_xml_node(user_display_name_cache = nil)
+ el1 = XML::Node.new 'node'
+ el1['id'] = self.id.to_s
+ el1['lat'] = self.lat.to_s
+ el1['lon'] = self.lon.to_s
+ el1['version'] = self.version.to_s
+ el1['changeset'] = self.changeset_id.to_s
+
+ user_display_name_cache = {} if user_display_name_cache.nil?
+
+ if user_display_name_cache and user_display_name_cache.key?(self.changeset.user_id)
+ # use the cache if available
+ elsif self.changeset.user.data_public?
+ user_display_name_cache[self.changeset.user_id] = self.changeset.user.display_name
+ else
+ user_display_name_cache[self.changeset.user_id] = nil
+ end
+
+ if not user_display_name_cache[self.changeset.user_id].nil?
+ el1['user'] = user_display_name_cache[self.changeset.user_id]
+ el1['uid'] = self.changeset.user_id.to_s
+ end
+
+ self.tags.each do |k,v|
+ el2 = XML::Node.new('tag')
+ el2['k'] = k.to_s
+ el2['v'] = v.to_s
+ el1 << el2
+ end
+
+ el1['visible'] = self.visible.to_s
+ el1['timestamp'] = self.timestamp.xmlschema
+ return el1
+ end
+
+ def tags_as_hash
+ return tags
+ end
+
+ def tags
+ unless @tags
+ @tags = {}
+ self.node_tags.each do |tag|
+ @tags[tag.k] = tag.v
+ end
+ end
+ @tags
+ end
+
+ def tags=(t)
+ @tags = t
+ end
+
+ def add_tag_key_val(k,v)
+ @tags = Hash.new unless @tags
+
+ # duplicate tags are now forbidden, so we can't allow values
+ # in the hash to be overwritten.
+ raise OSM::APIDuplicateTagsError.new if @tags.include? k
+
+ @tags[k] = v
+ end
+
+ ##
+ # are the preconditions OK? this is mainly here to keep the duck
+ # typing interface the same between nodes, ways and relations.
+ def preconditions_ok?
+ in_world?
+ end
+
+ ##
+ # dummy method to make the interfaces of node, way and relation
+ # more consistent.
+ def fix_placeholders!(id_map)
+ # nodes don't refer to anything, so there is nothing to do here
+ end
end