How to Extract data from XML using Nokogiri Ruby library? - ruby-on-rails

Question

Here is a sample of a XML data that is being fetched, from a seperate GTFS server (Transit Data):
<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<soap:Body>
<GetNextTripsForStopResponse xmlns="http://octranspo.com">
<GetNextTripsForStopResult>
<StopNo>3023</StopNo>
<StopLabel>HURDMAN</StopLabel>
<Error/>
<Route>
<RouteDirection>
<RouteNo>45</RouteNo>
<RouteLabel>Hospital</RouteLabel>
<Direction></Direction>
<Error>12</Error>
<RequestProcessingTime>20221212125854</RequestProcessingTime>
<Trips>
<Trip>
<Longitude/>
<Latitude/>
<GPSSpeed/>
<TripDestination>Hospital</TripDestination>
<TripStartTime>13:03</TripStartTime>
<AdjustedScheduleTime>4</AdjustedScheduleTime>
<AdjustmentAge>-1</AdjustmentAge>
<LastTripOfSchedule>false</LastTripOfSchedule>
<BusType/>
</Trip>
<Trip>
<Longitude/>
<Latitude/>
<GPSSpeed/>
<TripDestination>Hospital</TripDestination>
<TripStartTime>13:18</TripStartTime>
<AdjustedScheduleTime>19</AdjustedScheduleTime>
<AdjustmentAge>-1</AdjustmentAge>
<LastTripOfSchedule>false</LastTripOfSchedule>
<BusType/>
</Trip>
<Trip>
<Longitude/>
<Latitude/>
<GPSSpeed/>
<TripDestination>Hospital</TripDestination>
<TripStartTime>13:33</TripStartTime>
<AdjustedScheduleTime>34</AdjustedScheduleTime>
<AdjustmentAge>-1</AdjustmentAge>
<LastTripOfSchedule>false</LastTripOfSchedule>
<BusType/>
</Trip>
</Trips>
</RouteDirection>
</Route>
</GetNextTripsForStopResult>
</GetNextTripsForStopResponse>
</soap:Body>
</soap:Envelope>
I am trying to extract the data inside 'Trips' and use my maping to return the data. here is the mappinngs I am using:
#mappings = {
:next_for_route => {
'TripDestination' => { :key => :destination, :conv => lambda { |s| s } },
'TripStartTime' => { :key => :departure_from_origin, :conv => lambda { |s| hour_and_minutes_to_elapsed(s) } },
'AdjustedScheduleTime'=> { :key => :expected, :conv => lambda { |s| secs_elapsed_today + 60 * s.to_i } },
'AdjustmentAge' => { :key => :age, :conv => lambda { |s| '-1' == s ? nil : (s.to_f * 60).to_i } },
'BusType' => { :key => :bus_type, :conv => lambda { |s| s } },
'Latitude' => { :key => :latitude, :conv => lambda { |s| s.to_f } },
'Longitude' => { :key => :longitude, :conv => lambda { |s| s.to_f } },
'GPSSpeed' => { :key => :approximate_speed, :conv => lambda { |s| s.to_f } },
},
:route_summary => {
'RouteNo' => { :key => :route_no, :conv => lambda { |s| s.to_i } },
'DirectionID' => { :key => :direction_id, :conv => lambda { |s| s.to_i } },
'Direction' => { :key => :direction, :conv => lambda { |s| s } },
'RouteHeading' => { :key => :heading, :conv => lambda { |s| s } },
}
}
I tried the following but I still can't get the data. I am not sure why it isn't working I checked if my xpath works in online format checker and it worked.
def request(op, root, payload)
payload['appID'] = #app_id
payload['apiKey'] = #api_key
payload['format'] = 'xml'
resp = #conn.get("/v2.0/#{op}") do |req|
req.params = payload
end
doc = Nokogiri::XML(resp.body)
doc.namespace_inheritance = true
yield(doc.at_xpath("//#{root}"))
end
def apply_mapping(key, node, vals)
#mappings[key].each do |k, v|
n = node.css(k.to_s)
vals[v[:key].to_sym] = v[:conv].call(n.first.content) if n
end
vals
end
def next_for_route(stop_no, route_no)
# BUG: docs have <StopInfoData> as root node; running system yields <GetNextTripsForStopResult>
request('GetNextTripsForStop', 'GetNextTripsForStopAllRoutes', { 'stopNo' => stop_no, 'routeNo' => route_no }) do |root_node|
arr = root_node.at('/Trips/Trip') do |pn|
apply_mapping(:next_for_route, pn, { :stop_no => stop_no, :route_no => route_no })
end
yield(arr)
end
end