[#130] Change file extension requirement from .txt to .xml (#132)

* change file ext requirement from txt to xml

* test script change

.gitignore

@@ -1,6 +1,6 @@
 # Default storage file for addressbook : don't need to cleanup when running from IDE
 
-addressbook.txt
+addressbook.xml
 
 # Compiled classfiles
 bin/

doc/UserGuide.md

@@ -123,13 +123,13 @@ Address book data are saved in the hard disk automatically after any command tha
 There is no need to save manually.
 
 #### Changing the save location
-Address book data are saved in a file called `addressbook.txt` in the project root folder.
+Address book data are saved in a file called `addressbook.xml` in the project root folder.
 You can change the location by specifying the file path as a program argument.
 
 Example: 
-* `java seedu.addressbook.Main mydata.txt`
+* `java seedu.addressbook.Main mydata.xml`
 
-> The file name must end in `.txt` for it to be acceptable to the program.
+> The file name must end in `.xml` for it to be acceptable to the program.
 >
 > When running the program inside Eclipse, you can set command line parameters 
   before running the program.

src/seedu/addressbook/storage/StorageFile.java

@@ -26,7 +26,7 @@
 public class StorageFile {
 
     /** Default file path used if the user doesn't provide the file name. */
-    public static final String DEFAULT_STORAGE_FILEPATH = "addressbook.txt";
+    public static final String DEFAULT_STORAGE_FILEPATH = "addressbook.xml";
 
     /* Note: Note the use of nested classes below.
      * More info https://docs.oracle.com/javase/tutorial/java/javaOO/nested.html
@@ -74,16 +74,16 @@ public StorageFile(String filePath) throws InvalidStorageFilePathException {
 
         path = Paths.get(filePath);
         if (!isValidPath(path)) {
-            throw new InvalidStorageFilePathException("Storage file should end with '.txt'");
+            throw new InvalidStorageFilePathException("Storage file should end with '.xml'");
         }
     }
 
     /**
      * Returns true if the given path is acceptable as a storage file.
-     * The file path is considered acceptable if it ends with '.txt'
+     * The file path is considered acceptable if it ends with '.xml'
      */
     private static boolean isValidPath(Path filePath) {
-        return filePath.toString().endsWith(".txt");
+        return filePath.toString().endsWith(".xml");
     }
 
     /**

test/expected.txt

@@ -3,7 +3,7 @@
 || Welcome to your Address Book!
 || AddessBook Level 2 - Version 1.0
 || Launch command format: java seedu.addressbook.Main [STORAGE_FILE_PATH]
-|| Using storage file : addressbook.txt
+|| Using storage file : addressbook.xml
 || ===================================================
 || Enter command: || [Command entered:  sfdfd]
 || add: Adds a person to the address book. Contact details can be marked private by prepending 'p' to the prefix.

test/java/seedu/addressbook/storage/StorageFileTest.java

@@ -44,14 +44,14 @@ public void constructor_noTxtExtension_exceptionThrown() throws Exception {
     @Test
     public void load_invalidFormat_exceptionThrown() throws Exception {
         // The file contains valid xml data, but does not match the AddressBook class
-        StorageFile storage = getStorage("InvalidData.txt");
+        StorageFile storage = getStorage("InvalidData.xml");
         thrown.expect(StorageOperationException.class);
         storage.load();
     }
 
     @Test
     public void load_validFormat() throws Exception {
-        AddressBook actualAB = getStorage("ValidData.txt").load();
+        AddressBook actualAB = getStorage("ValidData.xml").load();
         AddressBook expectedAB = getTestAddressBook();
 
         // ensure loaded AddressBook is properly constructed with test data
@@ -72,7 +72,7 @@ public void save_validAddressBook() throws Exception {
         StorageFile storage = getTempStorage();
         storage.save(ab);
 
-        assertStorageFilesEqual(storage, getStorage("ValidData.txt"));
+        assertStorageFilesEqual(storage, getStorage("ValidData.xml"));
     }
 
     // getPath() method in StorageFile class is trivial so it is not tested
@@ -89,7 +89,7 @@ private StorageFile getStorage(String fileName) throws Exception {
     }
 
     private StorageFile getTempStorage() throws Exception {
-        return new StorageFile(testFolder.getRoot().getPath() + "/" + "temp.txt");
+        return new StorageFile(testFolder.getRoot().getPath() + "/" + "temp.xml");
     }
 
     private AddressBook getTestAddressBook() throws Exception {