Cannot read property 'decode' of undefined

[michaelgosling]

When attempting to use gtfs-rb, on this line: let feed = GtfsRealtimeBindings.FeedMessage.decode(body);, I get the error TypeError: Cannot read property 'decode' of undefined. This actually wasn't happening with the other repo, but I was getting null values for important information with that one.

[michaelgosling]

Here's the full code for inspection:

"use strict";
const express = require('express');
const GtfsRealtimeBindings = require('gtfs-rb');
const request = require('request');
const cors = require('cors');

const TRIP_UPDATES_URL = "http://gtfs.halifax.ca/realtime/TripUpdate/TripUpdates.pb";
const ALERTS_URL = "http://gtfs.halifax.ca/realtime/Alert/Alerts.pb";
const VEHICLE_POSITIONS_URL = "http://gtfs.halifax.ca/realtime/Vehicle/VehiclePositions.pb";

let tripUpdates = [];
let vehiclePositions = [];
let alerts = [];

/* Get Trip Updates */
function updateAndSendTripUpdates(origResponse) {
  let posReqSettings = {
    method: 'GET',
    url: TRIP_UPDATES_URL,
    encoding: null
  };
  request(posReqSettings, function (error, response, body) {
    if (!error && response.statusCode == 200) {
      let feed = GtfsRealtimeBindings.FeedMessage.decode(body);
      tripUpdates = [];
      feed.entity.forEach((entity) => tripUpdates.push(entity));
      origResponse.send(tripUpdates);
    }
  });
}

/* Start Server */
const app = express();
const port = 3000;
app.use(cors());

app.get('/', (request, response) => {
  response.send("");
});

app.get('/trip_updates', (request, response) => {
  updateAndSendTripUpdates(response);
});

app.listen(port, (err) => {
  if (err) return console.log('ERROR', err);
  console.log(`Server is listening on port ${port}`);
});

[ciolt]

You need to import gtfs-rb by referencing the transit_realtime property. It's a change from the old protobuf.js bindings generator, but this is done to separate namespaces.

Ex: This won't work

const gtfsRB = require('gtfs-rb')
gtfsRB.FeedMessage // won't work

This will:

const gtfsRB = require('gtfs-rb').transit_realtime
gtfsRB.FeedMessage // FeedMessage class, with encode/decode/etc.

What I do is something more like this keep my code from being cluttered with "gtfsRealtimeBindings.transit_realtime....etc" everywhere:

const gtfsRB = require('gtfs-rb').transit_realtime
// Deconstruct these classes from GTFS Realtime Bindings
const { FeedMessage, FeedHeader, FeedEntity, VehiclePosition } = gtfsRB

FeedMessage // valid FeedMessage class with all protobuf message methods

[michaelgosling]

Ohhh, that works perfectly. Thank you!