A small demo of how to create a "next bus" service based on scraping a specific bus service page, and displaying in a LaMetric compatible format.

index.js

// follow modules loaded via `npm i --save request cheerio`
const request = require('request');
const cheerio = require('cheerio');
const http = require('http');

http.createServer((req, res) => {
  getDueTimes().then(data => {
    res.writeHead(200, { 'content-type': 'application/json' });
    res.end(JSON.stringify(data));
  }).catch(error => {
    console.error(error);
    res.writeHead(500, { 'content-type': 'application/json' });
    res.end(JSON.stringify({ error }));
  });
}).listen(3000);


function getDueTimes() {
  // we're returning a promise so we can later reuse in
  // a web server
  return new Promise((resolve, reject) => {
    // make a GET request to get a page of the next due buses
    request({
      url: 'http://m.buses.co.uk/brightonbuses/operatorpages/mobilesite/stop.aspx?stopid=6979&device=&s=50&d=&stopcode=&source=siri'
    }, (error, res, body) => {
      // if there was something wrong with the request, print it
      // out and exit the function
      if (error) {
        return reject(error);
      }

      // …otherwise, load the HTML into Cheerio, which give
      // us jQuery-like access
      const $ = cheerio.load(body);

      // now query the DOM for the times (bespoke to your markup)
      // and return just the text for each of those nodes, note
      // that to get a _real_ array back, I have to use `.get()`
      // at the end.
      const times = $('.colDepartureTime').map((i, el) => {
        return $(el).text();
      }).get();

      // resolve the promise: specifically, return the times
      const icon = "i996"; // our bus icon
      const data = { frames: times.map(text => ({ text, icon })) };
      resolve(data);
    });
  });
}

package.json

{
  "name": "bus",
  "private": true,
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "start": "node index.js",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "cheerio": "^0.22.0",
    "request": "^2.79.0"
  }
}