Implemented AddMilestoneCommandParser

src/main/java/seedu/address/logic/commands/AddMilestoneCommand.java

@@ -7,6 +7,7 @@
 
 import seedu.address.logic.CommandHistory;
 import seedu.address.logic.commands.exceptions.CommandException;
+import seedu.address.logic.parser.AddMilestoneCommandParser;
 import seedu.address.logic.parser.exceptions.ParseException;
 import seedu.address.model.Model;
 import seedu.address.model.task.Milestone;
@@ -50,7 +51,7 @@ public CommandResult execute(Model model, CommandHistory history) throws Command
 
     @Override
     public Command parse(String arguments) throws ParseException {
-        return null;
+        return new AddMilestoneCommandParser().parse(arguments);
     }
 
     @Override

src/main/java/seedu/address/logic/parser/AddMilestoneCommandParser.java

@@ -0,0 +1,46 @@
+package seedu.address.logic.parser;
+
+import seedu.address.logic.commands.AddMilestoneCommand;
+import seedu.address.logic.parser.exceptions.ParseException;
+import seedu.address.model.task.Milestone;
+
+import java.util.stream.Stream;
+
+import static seedu.address.commons.core.Messages.MESSAGE_INVALID_COMMAND_FORMAT;
+import static seedu.address.logic.parser.CliSyntax.PREFIX_TITLE;
+import static seedu.address.logic.parser.CliSyntax.PREFIX_MILESTONE;
+import static seedu.address.logic.parser.CliSyntax.PREFIX_RANK;
+
+//@@author JeremyInElysium
+/**
+ * Parses input arguments and creates a new AddMilestoneCommand object
+ */
+public class AddMilestoneCommandParser implements Parser<AddMilestoneCommand> {
+
+    /**
+     * Returns true if none of the prefixes contain empty {@code Optional} values in the given
+     * {@code ArgumentMultiMap}.
+     */
+    private static boolean arePrefixesPresent(ArgumentMultimap argumentMultimap, Prefix... prefixes) {
+        return Stream.of(prefixes).allMatch(prefix -> argumentMultimap.getValue(prefix).isPresent());
+    }
+
+    @Override
+    public AddMilestoneCommand parse(String userInput) throws ParseException {
+        ArgumentMultimap argMultimap =
+                ArgumentTokenizer.tokenize(userInput, PREFIX_TITLE, PREFIX_MILESTONE, PREFIX_RANK);
+
+        if(!arePrefixesPresent(argMultimap, PREFIX_TITLE, PREFIX_MILESTONE, PREFIX_RANK)
+            || !argMultimap.getPreamble().isEmpty()) {
+            throw new ParseException(String.format(MESSAGE_INVALID_COMMAND_FORMAT, AddMilestoneCommand.MESSAGE_USAGE));
+        }
+
+        String title = ParserUtil.parseTitle(argMultimap.getValue(PREFIX_TITLE).get());
+        String milestoneDescription = ParserUtil.parseMilestoneDescription(argMultimap.getValue(PREFIX_MILESTONE).get());
+        String rank = ParserUtil.parseRank(argMultimap.getValue(PREFIX_RANK).get());
+
+        Milestone milestone = new Milestone(title, milestoneDescription, rank);
+
+        return new AddMilestoneCommand(milestone);
+    }
+}

src/main/java/seedu/address/logic/parser/ParserUtil.java

@@ -120,4 +120,23 @@ public static String parseYear(String year) throws ParseException {
         return trimmedYear;
     }
 
+    //@@author JeremyInElysium
+    /**
+     * Leading and trailing whitespaces will be trimmed from {@code String milestoneDescription}
+     */
+    public static String parseMilestoneDescription(String milestoneDescription) throws ParseException {
+        requireNonNull(milestoneDescription);
+        String trimmedMilestoneDescription = milestoneDescription.trim();
+        return trimmedMilestoneDescription;
+    }
+
+    /**
+     * Leading and trailing whitespaces will be trimmed from {@code String rank}
+     */
+    public static String parseRank(String rank) throws ParseException {
+        requireNonNull(rank);
+        String trimmedRank = rank.trim();
+        return trimmedRank;
+    }
+
 }

src/main/java/seedu/address/model/task/Milestone.java

@@ -7,16 +7,16 @@
 public class Milestone extends Task {
     //private final String title;
     //private final String milestone_description;
-    private final Integer rank;
+    private final String rank;
 
-    public Milestone(String title, String milestoneDescription, Integer rank) {
+    public Milestone(String title, String milestoneDescription, String rank) {
         super(title, milestoneDescription, new PriorityLevel("high"));
         //this.title = title;
         //this.milestoneDescription = milestoneDescription;
         this.rank = rank;
     }
 
-    public Integer getRank() {
+    public String getRank() {
         return rank;
     }