openstreetmap-website/app/models/way.rb
Simon Legner 413baecf6b Refactor generation of object metadata in API calls
Factor out duplicate from the object models into common code.
2013-12-04 00:09:52 +00:00

343 lines
10 KiB
Ruby

class Way < ActiveRecord::Base
require 'xml/libxml'
include ConsistencyValidations
include NotRedactable
include ObjectMetadata
self.table_name = "current_ways"
belongs_to :changeset
has_many :old_ways, -> { order(:version) }
has_many :way_nodes, -> { order(:sequence_id) }
has_many :nodes, -> { order("sequence_id") }, :through => :way_nodes
has_many :way_tags
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 :changeset_id,:version, :timestamp
validates_uniqueness_of :id
validates_inclusion_of :visible, :in => [ true, false ]
validates_numericality_of :changeset_id, :version, :integer_only => true
validates_numericality_of :id, :on => :update, :integer_only => true
validates_associated :changeset
scope :visible, -> { where(:visible => true) }
scope :invisible, -> { where(:visible => false) }
# Read in xml as text and return it's Way object representation
def self.from_xml(xml, create=false)
begin
p = XML::Parser.string(xml)
doc = p.parse
doc.find('//osm/way').each do |pt|
return Way.from_xml_node(pt, create)
end
raise OSM::APIBadXMLError.new("node", xml, "XML doesn't contain an osm/way element.")
rescue LibXML::XML::Error, ArgumentError => ex
raise OSM::APIBadXMLError.new("way", xml, ex.message)
end
end
def self.from_xml_node(pt, create=false)
way = Way.new
raise OSM::APIBadXMLError.new("way", pt, "Version is required when updating") unless create or not pt['version'].nil?
way.version = pt['version']
raise OSM::APIBadXMLError.new("way", pt, "Changeset id is missing") if pt['changeset'].nil?
way.changeset_id = pt['changeset']
unless create
raise OSM::APIBadXMLError.new("way", pt, "ID is required when updating") if pt['id'].nil?
way.id = pt['id'].to_i
# .to_i will return 0 if there is no number that can be parsed.
# We want to make sure that there is no id with zero anyway
raise OSM::APIBadUserInput.new("ID of way cannot be zero when updating.") if way.id == 0
end
# We don't care about the timestamp nor the visibility as these are either
# set explicitly or implicit in the action. The visibility is set to true,
# and manually set to false before the actual delete.
way.visible = true
# Start with no tags
way.tags = Hash.new
# Add in any tags from the XML
pt.find('tag').each do |tag|
raise OSM::APIBadXMLError.new("way", pt, "tag is missing key") if tag['k'].nil?
raise OSM::APIBadXMLError.new("way", pt, "tag is missing value") if tag['v'].nil?
way.add_tag_keyval(tag['k'], tag['v'])
end
pt.find('nd').each do |nd|
way.add_nd_num(nd['ref'])
end
return way
end
# Find a way given it's ID, and in a single SQL call also grab its nodes
#
# You can't pull in all the tags too unless we put a sequence_id on the way_tags table and have a multipart key
def self.find_eager(id)
way = Way.find(id, :include => {:way_nodes => :node})
#If waytag had a multipart key that was real, you could do this:
#way = Way.find(id, :include => [:way_tags, {:way_nodes => :node}])
end
# Find a way given it's ID, and in a single SQL call also grab its nodes and tags
def to_xml
doc = OSM::API.new.get_xml_doc
doc.root << to_xml_node()
return doc
end
def to_xml_node(visible_nodes = nil, changeset_cache = {}, user_display_name_cache = {})
el1 = XML::Node.new 'way'
el1['id'] = self.id.to_s
add_metadata_to_xml_node(el1, self, changeset_cache, user_display_name_cache)
# make sure nodes are output in sequence_id order
ordered_nodes = []
self.way_nodes.each do |nd|
if visible_nodes
# if there is a list of visible nodes then use that to weed out deleted nodes
if visible_nodes[nd.node_id]
ordered_nodes[nd.sequence_id] = nd.node_id.to_s
end
else
# otherwise, manually go to the db to check things
if nd.node and nd.node.visible?
ordered_nodes[nd.sequence_id] = nd.node_id.to_s
end
end
end
ordered_nodes.each do |nd_id|
if nd_id and nd_id != '0'
e = XML::Node.new 'nd'
e['ref'] = nd_id
el1 << e
end
end
self.way_tags.each do |tag|
e = XML::Node.new 'tag'
e['k'] = tag.k
e['v'] = tag.v
el1 << e
end
return el1
end
def nds
unless @nds
@nds = Array.new
self.way_nodes.each do |nd|
@nds += [nd.node_id]
end
end
@nds
end
def tags
unless @tags
@tags = {}
self.way_tags.each do |tag|
@tags[tag.k] = tag.v
end
end
@tags
end
def nds=(s)
@nds = s
end
def tags=(t)
@tags = t
end
def add_nd_num(n)
@nds = Array.new unless @nds
@nds << n.to_i
end
def add_tag_keyval(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("way", self.id, k) if @tags.include? k
@tags[k] = v
end
##
# the integer coords (i.e: unscaled) bounding box of the way, assuming
# straight line segments.
def bbox
lons = nodes.collect { |n| n.longitude }
lats = nodes.collect { |n| n.latitude }
BoundingBox.new(lons.min, lats.min, lons.max, lats.max)
end
def update_from(new_way, user)
Way.transaction do
self.lock!
check_consistency(self, new_way, user)
unless new_way.preconditions_ok?(self.nds)
raise OSM::APIPreconditionFailedError.new("Cannot update way #{self.id}: data is invalid.")
end
self.changeset_id = new_way.changeset_id
self.changeset = new_way.changeset
self.tags = new_way.tags
self.nds = new_way.nds
self.visible = true
save_with_history!
end
end
def create_with_history(user)
check_create_consistency(self, user)
unless self.preconditions_ok?
raise OSM::APIPreconditionFailedError.new("Cannot create way: data is invalid.")
end
self.version = 0
self.visible = true
save_with_history!
end
def preconditions_ok?(old_nodes = [])
return false if self.nds.empty?
if self.nds.length > MAX_NUMBER_OF_WAY_NODES
raise OSM::APITooManyWayNodesError.new(self.id, self.nds.length, MAX_NUMBER_OF_WAY_NODES)
end
# check only the new nodes, for efficiency - old nodes having been checked last time and can't
# be deleted when they're in-use.
new_nds = (self.nds - old_nodes).sort.uniq
unless new_nds.empty?
db_nds = Node.where(:id => new_nds, :visible => true)
if db_nds.length < new_nds.length
missing = new_nds - db_nds.collect { |n| n.id }
raise OSM::APIPreconditionFailedError.new("Way #{self.id} requires the nodes with id in (#{missing.join(',')}), which either do not exist, or are not visible.")
end
end
return true
end
def delete_with_history!(new_way, user)
unless self.visible
raise OSM::APIAlreadyDeletedError.new("way", new_way.id)
end
# need to start the transaction here, so that the database can
# provide repeatable reads for the used-by checks. this means it
# shouldn't be possible to get race conditions.
Way.transaction do
self.lock!
check_consistency(self, new_way, user)
rels = Relation.joins(:relation_members).where(:visible => true, :current_relation_members => { :member_type => "Way", :member_id => id }).order(:id)
raise OSM::APIPreconditionFailedError.new("Way #{self.id} is still used by relations #{rels.collect { |r| r.id }.join(",")}.") unless rels.empty?
self.changeset_id = new_way.changeset_id
self.changeset = new_way.changeset
self.tags = []
self.nds = []
self.visible = false
save_with_history!
end
end
# Temporary method to match interface to nodes
def tags_as_hash
return self.tags
end
##
# if any referenced nodes are placeholder IDs (i.e: are negative) then
# this calling this method will fix them using the map from placeholders
# to IDs +id_map+.
def fix_placeholders!(id_map, placeholder_id = nil)
self.nds.map! do |node_id|
if node_id < 0
new_id = id_map[:node][node_id]
raise OSM::APIBadUserInput.new("Placeholder node not found for reference #{node_id} in way #{self.id.nil? ? placeholder_id : self.id}") if new_id.nil?
new_id
else
node_id
end
end
end
private
def save_with_history!
t = Time.now.getutc
# update the bounding box, note that this has to be done both before
# and after the save, so that nodes from both versions are included in the
# bbox. we use a copy of the changeset so that it isn't reloaded
# later in the save.
cs = self.changeset
cs.update_bbox!(bbox) unless nodes.empty?
Way.transaction do
self.version += 1
self.timestamp = t
self.save!
tags = self.tags
WayTag.delete_all(:way_id => self.id)
tags.each do |k,v|
tag = WayTag.new
tag.way_id = self.id
tag.k = k
tag.v = v
tag.save!
end
nds = self.nds
WayNode.delete_all(:way_id => self.id)
sequence = 1
nds.each do |n|
nd = WayNode.new
nd.id = [self.id, sequence]
nd.node_id = n
nd.save!
sequence += 1
end
old_way = OldWay.from_way(self)
old_way.timestamp = t
old_way.save_with_dependencies!
# reload the way so that the nodes array points to the correct
# new set of nodes.
self.reload
# update and commit the bounding box, now that way nodes
# have been updated and we're in a transaction.
cs.update_bbox!(bbox) unless nodes.empty?
# tell the changeset we updated one element only
cs.add_changes! 1
cs.save!
end
end
end