allow passing FB event number as parameter

lib/crawler.js

@@ -1,13 +1,29 @@
 const request = require('request')
+const { checkURLFormat, checkNumberURLParameter } = require('./utils')
 
 const useMobileURL = (originalURL) => {
-  const url = new URL(originalURL)
+  const urlWithProtocol = originalURL.includes('http') ?
+    originalURL :
+    `https://${originalURL}`
+  const url = new URL(urlWithProtocol)
 
   return `${url.protocol}//mobile.facebook.com${url.port}${url.pathname}${url.hash}`
 }
 
+const createURL = (originalURL) => {
+  if (checkURLFormat(originalURL)) {
+    return originalURL
+  }
+
+  if (checkNumberURLParameter(originalURL)) {
+    return `https://facebook.com/events/${originalURL}`
+  }
+
+  return ''
+}
+
 const crawl = async (originalURL) => {
-  const url = useMobileURL(originalURL)
+  const url = useMobileURL(createURL(originalURL))
   return new Promise((resolve, reject) => {
     console.info(`Started request for URL: ${url}`)
     request({

lib/index.js

@@ -7,7 +7,7 @@ const rateLimit = require('express-rate-limit')
 const crawl = require('./crawler')
 const parseHTML = require('./parser')
 const generateICS = require('./ics')
-const { genericErrorHandler, checkFBURL } = require('./middlewares')
+const { genericErrorHandler, checkURLParameter } = require('./middlewares')
 
 const port = process.env.PORT
 const app = express()
@@ -36,9 +36,9 @@ app.get('*', (req, res) => {
   res.status(400).render('404')
 })
 
-app.use('/download', checkFBURL)
+app.use('/download', checkURLParameter)
 app.use('/download', rateLimit())
-app.post('/download', async (req, res) => {
+app.post('/download', async (req, res, next) => {
   const { url } = req.body
 
   try {
@@ -52,7 +52,8 @@ app.post('/download', async (req, res) => {
         .send(200, new Buffer(ics, 'utf8'))
     }
   } catch (err) {
-    return next(err)
+    next(err)
+    return
   }
 })
 

lib/middlewares.js

@@ -1,4 +1,5 @@
-const FBURLError = () => new Error('Not a valid Facebook URL!')
+const { checkValidURL } = require('./utils')
+const MissingURLParameter = () => new Error('Please provide valid URL or event number.')
 
 const sendJSON = (req) => {
   return req.accepts().includes('application/json')
@@ -19,27 +20,17 @@ const genericErrorHandler = (err, req, res, next) => {
     .render('error', { error: err.toString() })
 }
 
-const checkFBURL = (req, res, next) => {
+const checkURLParameter = (req, res, next) => {
   const { url } = req.body
 
-  if (!url) {
-    return next(FBURLError())
+  if (!url || !checkValidURL(url)) {
+    return next(MissingURLParameter())
   }
 
-  try {
-    const FBURL = new URL(url)
-    if (!(/facebook/.test(FBURL.hostname))) {
-      return next(FBURLError())
-    }
-  } catch (err) {
-    return next(err)
-  }
-
-
   return next()
 }
 
 module.exports = {
   genericErrorHandler,
-  checkFBURL,
+  checkURLParameter,
 }

lib/parser.js

@@ -1,5 +1,6 @@
 const dayjs = require('dayjs')
 const cheerio = require('cheerio')
+const { createParserError } = require('./utils')
 
 // NOTE: Specific formatting for `ics` library
 const parseDates = (startDate, endDate) => {
@@ -79,15 +80,16 @@ const parseHTML = (html) => {
       return data
     }, null)
 
-    const eventData = rawData ?
-      JSON.parse(rawData.slice(12, -5)) :
-      {}
+    if (!rawData) {
+      throw createParserError()
+    }
+
+    const eventData = JSON.parse(rawData.slice(12, -5))
     const data = parseEventData(eventData)
 
     return data
   } catch (err) {
     throw err
-    return
   }
 }
 

lib/public/scripts.js

@@ -270,6 +270,10 @@
       return
     }
 
+    if (!form.reportValidity()) {
+      return
+    }
+
     event.preventDefault()
 
     const formData = new URLSearchParams()

lib/public/service-worker.js

@@ -1,4 +1,4 @@
-// Worker v2
+// Worker v3
 
 self.addEventListener('install', (event) => {
   event.waitUntil(
@@ -6,8 +6,8 @@ self.addEventListener('install', (event) => {
       return cache.addAll([
         '/',
         '/favicon.ico',
-        '/scripts.js?2',
-        '/style.css?2',
+        '/scripts.js?3',
+        '/style.css?3',
       ])
     })
   )

lib/utils.js

@@ -0,0 +1,26 @@
+const checkValidURL = (url) => {
+  return checkURLFormat(url) ||
+    checkNumberURLParameter(url)
+}
+
+const checkURLFormat = (url) => {
+  return /^(http:\/\/www\.|https:\/\/www\.|http:\/\/|https:\/\/)?[a-z0-9]+([\-\.]{1}[a-z0-9]+)*\.[a-z]{2,5}(:[0-9]{1,5})?(\/.*)?$/.test(url)
+}
+
+const checkNumberURLParameter = (url) => {
+  return /^\d+$/.test(url)
+}
+
+const createParserError = () => {
+  const err = new Error('Unable to parse event data.')
+  err.statusCode = 422
+
+  return err
+}
+
+module.exports = {
+  checkValidURL,
+  checkURLFormat,
+  checkNumberURLParameter,
+  createParserError,
+}

lib/views/index.ejs

@@ -5,7 +5,7 @@
     <meta name="viewport" content="width=device-width, initial-scale=1">
     <link rel="manifest" href="/manifest.json">
     <link rel="apple-touch-icon" sizes="180x180" href="/icon-180.png">
-    <link rel="stylesheet" type="text/css" href="/style.css?2">
+    <link rel="stylesheet" type="text/css" href="/style.css?3">
     <title>Facebook Event to iCal Converter</title>
   </head>
 
@@ -24,7 +24,14 @@
       </p>
 
       <form action='/download' method='POST' id="form">
-        <input id="url" type='text' name='url' placeholder='Paste / type FB event URL here...' />
+        <input
+          required
+          pattern="^(http:\/\/www\.|https:\/\/www\.|http:\/\/|https:\/\/)?[a-z0-9]+([\-\.]{1}[a-z0-9]+)*\.[a-z]{2,5}(:[0-9]{1,5})?(\/.*)?|\d+$"
+          id="url"
+          name="url"
+          placeholder="Paste / type FB event URL or event number..."
+          title="Please insert Facebook Event URL / Number"
+        />
         <input id="submit" type='submit' value='Submit' />
       </form>
 
@@ -71,6 +78,6 @@
       <a href="#" title="Source code coming soon">Source</a>
     </footer>
 
-    <script src="/scripts.js?2"></script>
+    <script src="/scripts.js?3"></script>
   </body>
 </html>