Added measures to make sure the user logs into their schedule before fetching can commence

app/src/main/java/com/denizk0461/weserplaner/activity/FetcherActivity.kt

@@ -13,6 +13,7 @@ import com.denizk0461.weserplaner.data.showErrorSnackBar
 import com.denizk0461.weserplaner.data.showSnackBar
 import com.denizk0461.weserplaner.data.showToast
 import com.denizk0461.weserplaner.databinding.ActivityFetcherBinding
+import com.denizk0461.weserplaner.exception.NotLoggedInException
 import com.denizk0461.weserplaner.model.TextSheetContentId
 import com.denizk0461.weserplaner.sheet.TextSheet
 import com.denizk0461.weserplaner.viewmodel.FetcherViewModel
@@ -58,9 +59,7 @@ class FetcherActivity : FragmentActivity() {
         )
 
         // Enabling JavaScript. See comment above lint suppression for reason why this is done.
-        binding.webview.settings.apply {
-            javaScriptEnabled = true
-        }
+        binding.webview.settings.javaScriptEnabled = true
 
         binding.webview.webViewClient = object : WebViewClient() {
             // Disallow redirecting to prevent the app from launching Chrome after the user logs in
@@ -125,9 +124,7 @@ class FetcherActivity : FragmentActivity() {
 
         binding.fab.setOnClickListener {
 
-            if (binding.webview.url?.contains(
-                    scheduleUrl
-                ) == true) {
+            if (binding.webview.url?.contains(scheduleUrl) == true) {
                 /*
                  * Retrieve encoded HTML via JavaScript function. Encoding is done as otherwise not all
                  * symbols will be accurately fetched.
@@ -143,15 +140,27 @@ class FetcherActivity : FragmentActivity() {
                          * Notify the user that the fetch was successful, and tell the user how many
                          * items could not be fetched.
                          */
-                        showToast(this, when (elementsNotFetched) {
-                            0 -> getString(R.string.toast_fetch_finished_zero)
-                            1 -> getString(R.string.toast_fetch_finished_one)
-                            else -> getString(R.string.toast_fetch_finished_other, elementsNotFetched)
-                        })
+                        showToast(
+                            this, when (elementsNotFetched) {
+                                0 -> getString(R.string.toast_fetch_finished_zero)
+                                1 -> getString(R.string.toast_fetch_finished_one)
+                                else -> getString(
+                                    R.string.toast_fetch_finished_other,
+                                    elementsNotFetched
+                                )
+                            }
+                        )
 
                         // Close the activity
                         finish()
 
+                    } catch (e: NotLoggedInException) {
+                        // Let the user know that they need to log in
+                        theme.showErrorSnackBar(
+                            binding.coordinatorLayout,
+                            getString(R.string.fetch_error_login_snack),
+                            binding.bottomAppBar,
+                        )
                     } catch (e: IOException) {
                         // Let the user know that an error occurred
                         theme.showErrorSnackBar(

app/src/main/java/com/denizk0461/weserplaner/data/StudIPParser.kt

@@ -2,6 +2,7 @@ package com.denizk0461.weserplaner.data
 
 import android.app.Application
 import com.denizk0461.weserplaner.db.AppRepository
+import com.denizk0461.weserplaner.exception.NotLoggedInException
 import com.denizk0461.weserplaner.model.StudIPEvent
 import org.jsoup.Jsoup
 import org.jsoup.nodes.Document
@@ -20,10 +21,11 @@ class StudIPParser(application: Application) {
      * Parse a given HTML string. HTML must be of a Stud.IP timetable. May skip elements that don't
      * provide full information on an event (title, timeslot, lecturers, room).
      *
-     * @param html          website content of the Stud.IP timetable
-     * @throws IOException  when an error in fetching or the database transaction occurs
+     * @param html                  website content of the Stud.IP timetable
+     * @throws NotLoggedInException if the user has not logged in before starting the fetch
+     * @throws IOException          when an error in fetching or the database transaction occurs
      */
-    @Throws(IOException::class)
+    @Throws(NotLoggedInException::class, IOException::class)
     fun parse(html: String): Int {
         // Counts how many elements could not be successfully fetched
         var elementsNotFetched = 0
@@ -31,6 +33,11 @@ class StudIPParser(application: Application) {
         // Parse the HTML using Jsoup to traverse the document
         val doc = Jsoup.parse(html)
 
+        // Check if the user has logged in by checking the ID of the body tag
+        if (doc.body().id() != "calendar-schedule-index") {
+            throw NotLoggedInException()
+        }
+
         /*
          * Create the list that all events will be added to temporarily before saving them to
          * persistent storage.

app/src/main/java/com/denizk0461/weserplaner/exception/InvalidContentIdException.kt

@@ -1,5 +0,0 @@
-package com.denizk0461.weserplaner.exception
-
-import java.io.IOException
-
-class InvalidContentIdException : IOException()

app/src/main/java/com/denizk0461/weserplaner/exception/NotLoggedInException.kt

@@ -0,0 +1,8 @@
+package com.denizk0461.weserplaner.exception
+
+import java.io.IOException
+
+/**
+ * Exception used to let the user know that they need to log in in order to download their schedule.
+ */
+class NotLoggedInException : IOException()

app/src/main/java/com/denizk0461/weserplaner/exception/ParcelNotFoundException.kt

@@ -2,4 +2,7 @@ package com.denizk0461.weserplaner.exception
 
 import java.io.IOException
 
+/**
+ * This exception is fired whenever a parcel is not transmitted properly.
+ */
 class ParcelNotFoundException : IOException()

app/src/main/java/com/denizk0461/weserplaner/viewmodel/FetcherViewModel.kt

@@ -2,6 +2,7 @@ package com.denizk0461.weserplaner.viewmodel
 
 import android.app.Application
 import com.denizk0461.weserplaner.data.StudIPParser
+import com.denizk0461.weserplaner.exception.NotLoggedInException
 import java.io.IOException
 import kotlin.jvm.Throws
 
@@ -20,9 +21,11 @@ class FetcherViewModel(app: Application) : AppViewModel(app) {
     /**
      * Fetches and parses the user's Stud.IP schedule.
      *
-     * @param html  source code of the schedule website
+     * @param html                  source code of the schedule website
+     * @throws NotLoggedInException if the user has not logged in before starting the fetch
+     * @throws IOException          when an error in fetching or the database transaction occurs
      */
-    @Throws(IOException::class)
+    @Throws(NotLoggedInException::class, IOException::class)
     fun parse(html: String): Int =
         returnBlocking {
             parser.parse(html)

app/src/main/res/values-de/strings.xml

@@ -22,6 +22,7 @@
 
     <string name="fetch_error_snack">Ein Fehler ist aufgetreten!</string>
     <string name="fetch_error_webpage_snack">Du musst deinen Stundenplan öffnen!</string>
+    <string name="fetch_error_login_snack">Du musst dich zuerst einloggen!</string>
     <string name="canteen_fetch_error">Mensaplan konnte nicht heruntergeladen werden!</string>
 
     <string name="canteen_item_difference_text_one">Ein Angebot aufgrund deiner Präferenzen versteckt.</string>

app/src/main/res/values/strings.xml

@@ -23,6 +23,7 @@
 
     <string name="fetch_error_snack">Something went wrong!</string>
     <string name="fetch_error_webpage_snack">You must navigate to your schedule!</string>
+    <string name="fetch_error_login_snack">You must log in first!</string>
     <string name="canteen_fetch_error">Couldn\'t retrieve the canteen plan!</string>
 
     <string name="canteen_item_difference_text_one">One offer hidden due to your preferences.</string>