server/httphandler.js

   1 var url         = require('url'),
   2     fs          = require('fs'),
   3     node_static = require('node-static'),
   4     Negotiator  = require('negotiator'),
   5     _           = require('lodash'),
   6     config      = require('./configuration.js'),
   7     winston     = require('winston'),
   8     SettingsGenerator = require('./settingsgenerator.js'),
   9     Stats       = require('./stats.js');
  10
  11
  12
  13
  14 var HttpHandler = function (config) {
  15     var public_http = config.public_http || 'client/';
  16     this.file_server = new node_static.Server(public_http);
  17 };
  18
  19 module.exports.HttpHandler = HttpHandler;
  20
  21
  22
  23 HttpHandler.prototype.serve = function (request, response) {
  24     // The incoming requests base path (ie. /kiwiclient)
  25     var base_path, base_check,
  26         whitelisted_folders = ['/assets', '/src'],
  27         is_whitelisted_folder = false;
  28
  29     // Trim off any trailing slashes from the base_path
  30     base_path = global.config.http_base_path || '';
  31     if (base_path.substr(base_path.length - 1) === '/') {
  32         base_path = base_path.substr(0, base_path.length - 1);
  33     }
  34
  35     // Normalise the URL to compare against the base_path
  36     base_check = request.url;
  37     if (base_check.substr(base_check.length - 1) !== '/') {
  38         base_check += '/';
  39     }
  40
  41     // Normalise the URL we use by removing the base path
  42     if (base_check.indexOf(base_path + '/') === 0) {
  43         request.url = request.url.replace(base_path, '');
  44
  45     } else if (base_check !== '/') {
  46         // We don't handle requests outside of the base path and not /, so just 404
  47         response.writeHead(404);
  48         response.write('Not Found');
  49         response.end();
  50         return;
  51     }
  52
  53     // Map any whitelisted folders to the local directories
  54     whitelisted_folders.forEach(function(folder) {
  55         if (request.url.indexOf(folder) === 0) {
  56             is_whitelisted_folder = true;
  57         }
  58     });
  59
  60     // Any requests not for whitelisted assets returns the index page
  61     if (!is_whitelisted_folder) {
  62         request.url = '/index.html';
  63     }
  64
  65     if (request.url === '/index.html') {
  66         Stats.incr('http.homepage');
  67     }
  68
  69     // If the 'magic' translation is requested, figure out the best language to use from
  70     // the Accept-Language HTTP header. If nothing is suitible, fallback to our en-gb default translation
  71     if (request.url.substr(0, 16) === '/assets/locales/') {
  72         if (request.url === '/assets/locales/magic.json') {
  73             return serveMagicLocale.call(this, request, response);
  74         } else {
  75             response.setHeader('Content-Language', request.url.substr(16, request.url.indexOf('.') - 16));
  76         }
  77     } else if (request.url.substr(0, 21) === '/assets/settings.json') {
  78         return serveSettings.call(this, request, response);
  79     }
  80
  81     this.file_server.serve(request, response, function (err) {
  82         if (err) {
  83             response.writeHead(err.status, err.headers);
  84             response.end();
  85         }
  86     });
  87 };
  88
  89
  90 // Cached list of available translations
  91 var cached_available_locales = [];
  92
  93 // Get a list of the available translations we have
  94 fs.readdir('client/assets/locales', function (err, files) {
  95     if (err) {
  96         if (err.code === 'ENOENT') {
  97             winston.error('No locale files could be found at ' + err.path);
  98         } else {
  99             winston.error('Error reading locales.', err);
 100         }
 101     }
 102
 103     (files || []).forEach(function (file) {
 104         if (file.substr(-5) === '.json') {
 105             cached_available_locales.push(file.slice(0, -5));
 106         }
 107     });
 108 });
 109
 110
 111
 112 /**
 113  * Handle the /assets/locales/magic.json request
 114  * Find the closest translation we have for the language
 115  * set in the browser.
 116  **/
 117 var serveMagicLocale = function (request, response) {
 118     var default_locale_id = 'en-gb',
 119         found_locale, negotiator;
 120
 121     if (!request.headers['accept-language']) {
 122         // No accept-language specified in the request so send the default
 123         found_locale = default_locale_id;
 124
 125     } else {
 126         negotiator = new Negotiator(request);
 127         found_locale = negotiator.language(cached_available_locales);
 128
 129         // If a locale couldn't be negotiated, use the default
 130         found_locale = found_locale || default_locale_id;
 131     }
 132
 133     // Send a locale to the browser
 134     this.file_server.serveFile('/assets/locales/' + found_locale + '.json', 200, {
 135         Vary: 'Accept-Language',
 136         'Content-Language': found_locale
 137     }, request, response);
 138 };
 139
 140
 141
 142 /**
 143  * Handle the settings.json request
 144  */
 145 var serveSettings = function(request, response) {
 146     var referrer_url,
 147         debug = false,
 148         settings;
 149
 150     // Check the referrer for a debug option
 151     if (request.headers['referer']) {
 152         referrer_url = url.parse(request.headers['referer'], true);
 153         if (referrer_url.query && referrer_url.query.debug) {
 154             debug = true;
 155         }
 156     }
 157
 158     SettingsGenerator.get(debug, function(settings) {
 159         if (request.headers['if-none-match'] && request.headers['if-none-match'] === settings.hash) {
 160             response.writeHead(304, 'Not Modified');
 161             return response.end();
 162         }
 163
 164         response.writeHead(200, {
 165             'ETag': settings.hash,
 166             'Content-Type': 'application/json'
 167         });
 168         response.end(settings.settings);
 169     });
 170 };