iP: Week 3

Level 7. Save

Save the tasks in the hard disk automatically whenever the task list changes. Load the data from the hard disk when Duke starts up. You may hard-code the file name and location e.g., [project_root]/data/duke.txt

The format of the file is up to you. Example:

T | 1 | read book
D | 0 | return book | June 6th
E | 0 | project meeting | Aug 6th 2-4pm
T | 1 | join sports club

If you use file paths in your code,

• remember to use relative paths rather than absolute paths such as C:\data. If not, your app can cause unpredictable results when used in another computer.
• remember to specify file paths in an OS-independent way. If not, your app might not work when used on a different OS.

Your code must i.e., if the file is missing, your code must creat ithandle the case where the data file doesn't exist at the start. Reason: when someone else takes your Duke and runs it for the first time, the required file might not exist in their computer. Similarly, if you expect the data file to be in as specific folder (e.g., ./data/), you must also handle the folder-does-not-exist-yet case.

Level 8. Dates and Times

Teach Duke how to understand dates and times. For example, if the command is deadline return book /by 2/12/2019 1800, Duke should understand 2/12/2019 1800 as 2nd of December 2019, 6pm, instead of treating it as just a String.

• Minimal: Store deadline dates as a java.time.LocalDate in your task objects. Accept dates in a format such as yyyy-mm-dd format (e.g., 2019-10-15) and print in a different format such as MMM dd yyyy e.g., (Oct 15 2019).
• Stretch goal: Use dates and times in more meaningful ways. e.g., add a command to print deadlines/events occurring on a specific date.

import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.time.temporal.ChronoUnit;

public class Main {
    public static void main(String[] args) {
        //create dates from strings
        LocalDate d1 = LocalDate.parse("2019-12-01");
        LocalDate d2 = LocalDate.parse("2019-12-02");
        LocalDate d3 = LocalDate.parse("2019-12-02");
        
        //compare dates
        System.out.println(d1.isBefore(d2)); // -> true
        System.out.println(d1.isAfter(d2)); // -> false
        System.out.println(d2.equals(d3)); // -> true
        
        //work with dates
        System.out.println(d1.getDayOfWeek()); // -> SUNDAY
        System.out.println(d1.getMonth()); // -> DECEMBER
        System.out.println(d1.plus(1, ChronoUnit.YEARS));  // -> 2020-12-01
        
        // get today's date and print it in a specific format
        LocalDate d4 = LocalDate.now();
        System.out.println(d4); // -> 2019-10-15
        System.out.println(d4.format(DateTimeFormatter.ofPattern("MMM d yyyy"))); // -> Oct 15 2019
    }
}

Refactor the code to extract out closely related code as classes.

• Minimal: Extract the following classes:
  • Ui: deals with interactions with the user
  • Storage: deals with loading tasks from the file and saving tasks in the file
  • Parser: deals with making sense of the user command
  • TaskList: contains the task list e.g., it has operations to add/delete tasks in the list

public class Duke {

    private Storage storage;
    private TaskList tasks;
    private Ui ui;

    public Duke(String filePath) {
        ui = new Ui();
        storage = new Storage(filePath);
        try {
            tasks = new TaskList(storage.load());
        } catch (DukeException e) {
            ui.showLoadingError();
            tasks = new TaskList();
        }
    }

    public void run() {
        //...
    }

    public static void main(String[] args) {
        new Duke("data/tasks.txt").run();
    }
}

• Stretch Goal: Consider extracting more classes. e.g., *Command classes (i.e., AddCommand, DeleteCommand, ExitCommand etc.) that inherits from an abstract Command class, so that you can write the main logic of the App as follows:

  public void run() {
      ui.showWelcome();
      boolean isExit = false;
      while (!isExit) {
          try {
              String fullCommand = ui.readCommand();
              ui.showLine(); // show the divider line ("_______")
              Command c = Parser.parse(fullCommand);
              c.execute(tasks, ui, storage);
              isExit = c.isExit();
          } catch (DukeException e) {
              ui.showError(e.getMessage());
          } finally {
              ui.showLine();
          }
      }
  }
  

  You can get some inspiration from how the code of the addressbook-level2 is organized.

Organize the classes into suitable java packages.

• Minimal: put all classes in one package e.g., duke
• Stretch goal: divide into multiple packages as the number of classes increase e.g., duke.task, duke.command

Add JUnit tests to test the behavior of the code.

Requirements:

• Minimum: More than two test methods, preferably targeting more than one class (if you have multiple classes)
• Stretch goal: test methods to target all public methods of all classes

Refer to the JUnit tutorial @se-edu/guides to find how to use JUnit.

Package the app as an executable JAR file so that it can be distributed easily.

You can assume the user will run the jar file in the following way only:

• Copy the jar file into an empty folder
• Open a command window in that folder
• Run the command java -jar {filename}.jar e.g., java -jar Duke.jar (i.e., run the command in the same folder as the jar file)

Refer to the tutorial Working with JAR files @SE-EDU/guides to find how to create JAR files.

Do not commit the JAR file created. Instead, you can make the JAR file available in the following manner.

• Go to your fork on GitHub and create a new release.
• In the page where you fill the details of the release,
  • give an appropriate version number e.g., v0.1
  • attach the JAR file where it says Attach binaries by dropping them ....

Add JavaDoc comments to the code.

• Minimal: Add header comments to at least half of the non-private classes/methods.
• Stretch goal: Add header comments to all non-private classes/methods, and non-trivial private methods.

Tweak the code to comply with a given coding standard. From this point onward, ensure any new code added are compliant with the given coding standard.

Level 9. Find

Give users a way to find a task by searching for a keyword.

Example:

find book
    ____________________________________________________________
     Here are the matching tasks in your list:
     1.[T][✓] read book
     2.[D][✓] return book (by: June 6th)
    ____________________________________________________________