restbus/lib/api/agencies.js

RESTful JSON API for the NextBus Inc. public XML feed.

var https = require('https');
var utils = require('../utils');
var NBXML_FEED = utils.c.NEXTBUS_XMLFEED;
var agencies = {};

function getJson($) {
  var agency = {
    id: $.tag,
    title: $.title,
    region: $.regionTitle
  };

  return agency;
}

function getLinks(hrefs, agency, req) {
  var params = req.params,
    s = {
      href: hrefs.self,
      type: utils.c.MTJSON,
      rel: 'self',
      rt: utils.c.AGY,
      title: "Transit agency '" + agency.id + "'."
    },
    r = {
      href: hrefs.route,
      type: utils.c.MTJSON,
      rel: 'describedby',
      rt: utils.c.RTE,
      title: "A collection of routes for transit agency '" + agency.id + "'."
    },
    v = {
      href: hrefs.vehicle,
      type: utils.c.MTJSON,
      rel: 'describedby',
      rt: utils.c.VEH,
      title: "A collection of vehicles for transit agency '" + agency.id + "'."
    },
    a = {
      href: hrefs.agency,
      type: utils.c.MTJSON,
      rel: 'bookmark',
      rt: utils.c.AGY,
      title: 'A collection of transit agencies. This is the API root!'
    },
    to = [],
    from = [];

  if (params.agency) {
    to = to.concat([r, v]);
    from.push(a);
  } else {
    to.push(s);
    from.push(a);
  }

  return { self: s, to: to, from: from };
}

agencies.list = function (req, res) {
  https
    .get(utils.getOptionsWithPath(NBXML_FEED + '?command=agencyList'), function (nbres) {
      utils.getJsFromXml(nbres, function (err, js) {
        var json = [],
          uri;

        if (!err) {
          uri = utils.getOpenPath(req);

          js.body.agency.forEach(function (agency) {
            var $ = agency.$,
              a = getJson($),
              hrefself = [uri, '/', a.id].join(''),
              vuri = [hrefself, '/', 'vehicles'].join(''),
              ruri = [hrefself, '/', 'routes'].join('');

            if (req.query.links !== 'false') {
              a._links = getLinks(
                { self: hrefself, route: ruri, vehicle: vuri, agency: uri },
                a,
                req
              );
            }

            json.push(a);
          });
          res.status(200).json(json);
        } else utils.streamOrParseError(err, js, res);
      });
    })
    .on('error', function (e) {
      utils.nbRequestError(e, res);
    });
};

agencies.get = function (req, res) {
  var agency_id = req.params.agency;

  https
    .get(utils.getOptionsWithPath(NBXML_FEED + '?command=agencyList'), function (nbres) {
      utils.getJsFromXml(nbres, function (err, js) {
        var json = false,
          uri,
          ruri,
          vuri,
          auri;

        if (!err) {
          uri = utils.getOpenPath(req);
          js.body.agency.every(function (agency) {
            var $ = agency.$;

            if ($.tag == agency_id) {
              json = getJson($);
              ruri = uri + '/routes';
              vuri = uri + '/vehicles';
              auri = uri.replace('/' + json.id, '');

              if (req.query.links !== 'false') {
                json._links = getLinks(
                  { self: uri, route: ruri, vehicle: vuri, agency: auri },
                  json,
                  req
                );
              }
            } else return true; // Keep looping.
          });
          if (json) res.status(200).json(json);
          else
            res
              .status(404)
              .json(utils.errors.get(404, 'Agency id not found: ' + agency_id));
        } else utils.streamOrParseError(err, js, res);
      });
    })
    .on('error', function (e) {
      utils.nbRequestError(e, res);
    });
};

module.exports = agencies;