Merge pull request #138 from wendelinwemhoener/disallow-empty-flashcards

Disallow creating empty flashcards

Author: wendelinwemhoener

data/flashcards/flashcard.txt

@@ -3,3 +3,4 @@
 7 | Hello | Duke | 5 
 9 | id | checker | 5 
 10 | id increases | correctly | 5 
+11 |    f  | dfdf | 5 

src/main/java/seedu/duke/flashcard/command/CreateFlashcardCommand.java

@@ -23,6 +23,15 @@ public class CreateFlashcardCommand extends FlashcardCommand {
     public void execute(Scanner scanner, FlashcardList flashcardList) {
         System.out.print("    Enter the front page text: ");
         String frontPageText = scanner.nextLine();
+
+        while (frontPageText.strip().equals("")) {
+            System.out.println("        Invalid input! The front text must " +
+                    "contain at least one letter or digit!");
+
+            System.out.print("    Enter the front page text: ");
+            frontPageText = scanner.nextLine();
+        }
+
         System.out.print("    Enter the back page text: ");
         String backPageText = scanner.nextLine();