Javascript classes generated from the GTFS-realtime protocol buffer specification.
npm install gtfs-realtime-bindings
Provides JavaScript classes and their associated types generated from the
GTFS-realtime Protocol
Buffer specification. These classes will allow you to parse a binary Protocol
Buffer GTFS-realtime data feed into JavaScript objects.
These bindings are designed to be used in the Node.js
environment, but with some effort, they can probably be used in other
JavaScript environments as well.
We use the ProtoBuf.js library for
JavaScript Protocol Buffer support.
To use the gtfs-realtime-bindings classes in your own project, you need to
first install our Node.js npm package:
``
npm install gtfs-realtime-bindings
The following Node.js code snippet demonstrates downloading a GTFS-realtime
data feed from a particular URL, parsing it as a FeedMessage (the root type of
the GTFS-realtime schema), and iterating over the results.
In order to make this example work, you must first install node-fetch with NPM.
_Note: this exemple is using ES modules (import/export syntax) and is not compatiblerequire
with CommonJS ( syntax). You can use CommonJS by converting import to require
and installing . Learn more about ES modules here._
`javascript
import GtfsRealtimeBindings from "gtfs-realtime-bindings";
import fetch from "node-fetch";
(async () => {
try {
const response = await fetch("
headers: {
"x-api-key": "
// replace with your GTFS-realtime source's auth token
// e.g. x-api-key is the header value used for NY's MTA GTFS APIs
},
});
if (!res.ok) {
const error = new Error(${res.url}: ${res.status} ${res.statusText});``
error.response = res;
throw error;
process.exit(1);
}
const buffer = await response.arrayBuffer();
const feed = GtfsRealtimeBindings.transit_realtime.FeedMessage.decode(
new Uint8Array(buffer)
);
feed.entity.forEach((entity) => {
if (entity.tripUpdate) {
console.log(entity.tripUpdate);
}
});
}
catch (error) {
console.log(error);
process.exit(1);
}
})();
For more details on the naming conventions for the JavaScript classes generated
from the
gtfs-realtime.proto,
check out the ProtoBuf.js project
which we use to handle our Protocol Buffer serialization.