Acknowledgements

Setting up, getting started

Refer to the guide Setting up and getting started.

Design

:bulb: Tip: The .puml files used to create diagrams in this document can be found in the diagrams folder. Refer to the PlantUML Tutorial at se-edu/guides to learn how to create and edit diagrams.

Architecture

The Architecture Diagram given above explains the high-level design of the App.

Given below is a quick overview of main components and how they interact with each other.

Main components of the architecture

Main has two classes called Main and MainApp. It is responsible for,

  • At app launch: Initializes the components in the correct sequence, and connects them up with each other.
  • At shut down: Shuts down the components and invokes cleanup methods where necessary.

Commons represents a collection of classes used by multiple other components.

The rest of the App consists of four components.

  • UI: The UI of the App.
  • Logic: The command executor.
  • Model: Holds the data of the App in memory.
  • Storage: Reads data from, and writes data to, the hard disk.

How the architecture components interact with each other

The Sequence Diagram below shows how the components interact with each other for the scenario where the user issues the command rm CS2103.

Each of the four main components (also shown in the diagram above),

  • defines its API in an interface with the same name as the Component.
  • implements its functionality using a concrete {Component Name}Manager class (which follows the corresponding API interface mentioned in the previous point.

For example, the Logic component defines its API in the Logic.java interface and implements its functionality using the LogicManager.java class which follows the Logic interface. Other components interact with a given component through its interface rather than the concrete class (reason: to prevent outside component’s being coupled to the implementation of a component), as illustrated in the (partial) class diagram below.

The sections below give more details of each component.

UI component

The API of this component is specified in Ui.java

Structure of the UI Component

The UI consists of a MainWindow that is made up of parts e.g.CommandBox, ResultDisplay, ModuleListPanel, SavedModuleListPanel, StatusBarFooter etc. All these, including the MainWindow, inherit from the abstract UiPart class which captures the commonalities between classes that represent parts of the visible GUI.

Modules are represented by ModuleCard and SavedModuleCard respectively. These parts encapsulate Pills to capture information such as the semester that the mod is available in and the Module Credits of that mod.

The UI component uses the JavaFx UI framework. The layout of these UI parts are defined in matching .fxml files that are in the src/main/resources/view folder. For example, the layout of the MainWindow is specified in MainWindow.fxml

The UI component,

  • executes user commands using the Logic component.
  • listens for changes to Model data so that the UI can be updated with the modified data.
  • keeps a reference to the Logic component, because the UI relies on the Logic to execute commands.
  • depends on some classes in the Model component, as it displays ModuleCard object residing in the Model.

Logic component

API : Logic.java

Here’s a (partial) class diagram of the Logic component:

How the Logic component works:

  1. When Logic is called upon to execute a command, it uses the CliModsParser class to parse the user command.
  2. This results in a Command object (more precisely, an object of one of its subclasses e.g., ListCommand) which is executed by the LogicManager.
  3. The command can communicate with the Model when it is executed (e.g. list all modules offered by the CS Faculty).
  4. The result of the command execution is encapsulated as a CommandResult object which is returned from Logic.

The Sequence Diagram below illustrates the interactions within the Logic component for the execute("rm cs2103") API call.

Interactions Inside the Logic Component for the `rm CS2103` Command

:information_source: Note: The lifeline for DeleteCommandParser should end at the destroy marker (X) but due to a limitation of PlantUML, the lifeline reaches the end of diagram.

Here are the other classes in Logic (omitted from the class diagram above) that are used for parsing a user command:

How the parsing works:

  • When called upon to parse a user command, the CliModsParser class creates an XYZCommandParser (XYZ is a placeholder for the specific command name e.g., AddCommandParser) which uses the other classes shown above to parse the user command and create a XYZCommand object (e.g., AddCommand) which the CliModsParser returns back as a Command object.
  • All XYZCommandParser classes (e.g., AddCommandParser, DeleteCommandParser, …) inherit from the Parser interface so that they can be treated similarly where possible e.g, during testing.

Model component

API : Model.java

The Model component,

  • stores the module list data i.e., all Person objects (which are contained in a UniquePersonList object).
  • stores the currently ‘selected’ Person objects (e.g., results of a search query) as a separate filtered list which is exposed to outsiders as an unmodifiable ObservableList<Person> that can be ‘observed’ e.g. the UI can be bound to this list so that the UI automatically updates when the data in the list change.
  • stores a UserPref object that represents the user’s preferences. This is exposed to the outside as a ReadOnlyUserPref objects.
  • does not depend on any of the other three components (as the Model represents data entities of the domain, they should make sense on their own without depending on other components)

Storage component

API : Storage.java

The Storage component,

  • can save both module list data and user preference data in json format, and read them back into corresponding objects.
  • inherits from both CliModsStorage and UserPrefStorage, which means it can be treated as either one (if only the functionality of only one is needed).
  • depends on some classes in the Model component (because the Storage component’s job is to save/retrieve objects that belong to the Model)

Common classes

Classes used by multiple components are in the nus.climods.commons package.

Implementation

This section describes some noteworthy details on how certain features are implemented.

Add Module with Semester Feature

Implementation

The add command allows the user to add for a particular UserModule together with SemesterData. It is facilitated by AddCommand. It extends the Command class.

Users can add their UserModule with the Command:

  • add <MODULE_CODE> <SEMESTER_CODE>
  • e.g. add CS1101S s1

Parsing of commands

PositionalParameter manages parsing and error handling for parameters expected to be at a certain index in the list of arguments. New parameter classes can extend from PositionalParameter to support repeated parameters across commands, e.g module code.

ModuleCodeParameter checks if the user’s input fits the module code format. An exception is thrown if the module code supplied had an incorrect format.

SemesterParameter will check for valid semester code input. An exception will be thrown if semester code is invalid.

Design Considerations:

  • Create a SemesterParameter class
  • Modify AddCommand class

Command History - <Up>/<Down> command

The command history feature allows user to traverse and scroll through the command history that is recorded when he/she uses CliMods. The goal is to mirror the behavior of a terminal/shell interface where user can easily access his/her previous command by using the up and down arrow keys.

Implementation

The command history is facilitated by CommandSession. The aim of CommandSession is to act as a lightweight wrapper around the command execution process, handling the reading and writing to and from the command history.

Within CommandSession, we make use of an index pointer (commandHistoryPos) to keep track of which position the user is currently at in the command history. The use of the index pointer allows us to create a generator-like method to update and retrieve the user position in the command history.

  • CommandSession::getPreviousCommand()
    • Retrieves the previous command in the command history, and updates the internal index pointer to the next position (upward) in the command history.
  • CommandSession::getNextCommand()
    • Retrieves the next command in the command history, and updates the internal index pointer to the next position (downwards) in the command history.

Note that both of these operations are not pure, since the internal index pointer is updated after an invocation of either operations.

Design considerations

Depending on the shell, the behavior of how command history is being stored is different. For example, all commands are recorded in bash, while in zsh, no consecutive duplicate commands will be recorded.

CLiMods chose to emulate the zsh behavior instead as it reduces clutter in the command history. We also hope that this would improve user experience as it aims to also speed up the traversal of the command history.

UserGuide - help command

The help command displays our User Guide in a new window, using javafx WebViewer. It acts as a browser, so we prevent the user from connecting to other websites that is not within our control.

It is added this way because the user guide website is automatically built from our markdown file. This makes it easier to maintain changes in the user guide or developer guide. We do not control other websites, and we want the user to only view the user guide and other information on our website.

We also considered just displaying the link with a Copy URL button. However, the user has to copy the link into their web browser, making the user experience not smooth.

Documentation, logging, testing, configuration, dev-ops

Appendix: Requirements

Product scope

Product scope

  • Provides updated information and data based on curriculum and module schedule based on NUSMods.

Target user profile:

  • has a plan to map, plan and organize a timetable that has over 1000 potential modules to fill up with.
  • prefer desktop apps over other types
  • can type fast
  • prefers typing to mouse interactions
  • is reasonably comfortable using CLI apps

Value proposition: manage contacts faster than a typical mouse/GUI driven app

User stories

Link to Most Updated User Stories: Click here

Priorities: High (must have) - * * *, Medium (nice to have) - * *, Low (unlikely to have) - *

Priority As a …​ I want to …​ So that I can…​
* * * student see usage instructions refer to instructions when I forget the commands
* * * student add modules to my timetable edit and organize my timetable
* * * NUS student who is not too proficient in CLI easily adapt and learn the functions and commands the application has use the application efficiently
* * * student delete a module remove modules that I no longer need
* * * student search a module by name locate details of the module without having to go through the entire list
* * * student view pre-requisites for a class, and what class is a pre-requisite plan my studies appropriately
* * * student search for and add classes from NUSMods to my schedule have the most up to date information on my schedule
* * * student interested in CLI apps have most/all key features to be accessible by just the keyboard harness the full potential of CLI apps
* * * forgetful student easily access my weekly/daily schedule (time, venue and details of lesson) attend my lessons punctually
* * * student that work in areas with poor internet connection access the features in CLIMods still use CLIMods
* * * student (non freshman) track and add modules I have taken keep track of my progress in University
* * * student know what modules are offered in NUS find modules to do to fulfill my graduation requirement
* * potential user exploring CLIMods have a tutorial or detailed documentation on features of app easily adapt and use the app proficiently

Use cases

(For all use cases below, the System is the CLIMods and the Actor is the user, unless specified otherwise)

Use case: Find a module

MSS

  1. User requests to find a module
  2. CLIMods requests for details of the module to find
  3. User enters the requested details

  4. CLIMods finds and display details of the module

    Use case ends.

Extensions

  • 3a. The given module request is invalid.

    • 3a1. CLIMods shows an error message where module does not exist.

  • 3b. The user’s command is invalid.

    • 3a1. CLIMods shows an error message where command is non-existent.

      Use case resumes at step 2.

Use case: Add a module

MSS

  1. User requests to add a module
  2. CLIMods requests for details of the module to add
  3. User enters the requested details

  4. CLIMods adds the module

    Use case ends.

Extensions

  • 3a. The given module request is invalid.

    • 3a1. CLIMods shows an error message where module does not exist.

  • 3b. The user’s command is invalid.

    • 3a1. CLIMods shows an error message where command is non-existent.

      Use case resumes at step 2.

Use case: Delete a module

MSS

  1. User requests to list modules
  2. CLIMods shows a list of modules
  3. User requests to delete a specific module in the list

  4. CLIMods deletes the module

    Use case ends.

Extensions

  • 2a. The list is empty.

    Use case ends.

  • 3a. The given name is invalid.

    • 3a1. CLIMods shows an error message.

      Use case resumes at step 2.

Use case: Selecting Lesson Slot

MSS

  1. User requests to view a specific module
  2. CLIMods shows detailed information of that module
  3. User clicks on the desired lesson type
  4. CLIMods shows all lesson slots under that lesson type for the module
  5. User picks a lesson slot using the pick command

  6. CLIMods adds the lesson slot under the My Modules list

    Use case ends.

Extensions

  • 5a. The module has not been added

    • 5a1. CLIMods shows an error message.

  • 1a. The given module code is invalid

    • 3a1. CLIMods shows an error message.

Non-Functional Requirements

  1. Should work on any mainstream OS as long as it has Java 11 or above installed.
  2. Should be able to hold up to 1000 modules without a noticeable sluggishness in performance for typical usage.
  3. Connected to internet

Glossary

  • Student: The person who uses the app
  • Module(s): The modules/class to be taken by the students

The picture below shows the terms used for different parts of the UI shown on CLIMods.

  1. Module list: List of modules offered by NUS. Possibly filtered according to execution of various commands
  2. My modules: List of modules the user is taking
  3. Result window: Window showing result after execution of commands
  4. Command box: Box where the user types commands ——————————————————————————————————————–

Appendix: Instructions for manual testing

Given below are instructions to test the app manually.

:information_source: Note: These instructions only provide a starting point for testers to work on; testers are expected to do more exploratory testing.

Launch and shutdown

Refer to instructions in Quick Start for launch. Use the exit command to shutdown the application.

add: Adding a module

  1. Prerequisite: CS2103 has not been added to My modules.
  2. Type add CS2103 s1 in the command box to add CS2103 to your module list (under Semester 1)
  3. Expected result: CS2103 is now added to My modules
  4. Typing the same command as in Step 1 should now show an error message in the result window as CS2103 has already been added

view: Viewing classes for a module

  1. Type view CS2103 in the command box
  2. The detailed description for CS2103 is now visible in the module list

pick: Picking classes for a module

  1. Prerequisite: Add CS2103 to My modules by typing add CS2103 s1
  2. Type pick CS2103 tut 02 to add tutorial 2 to picked classes for CS2103
  3. Expected result: Tutorial 02 is added to your class list for CS2103 under My modules

preq: Viewing prerequisites for a module

  1. Type preq CS2103 in the command box
  2. Expected result: The module list is now filtered to show some prerequisites of CS2103. As explained in the User Guide, not all prerequisites are necessarily shown in the module list due to limitations of the NUSMods API.

rm: Deleting a User Module

  1. Deleting a module while all User Modules are being shown

    1. Prerequisites: Open CLIMods and add CS2103 by typing add cs2103 in the command box

    2. Test case: rm cs2103
      Expected: CS2103 is deleted and removed from My Modules. A success message of “Deleted Module: CS2103” should be displayed in the result window

    3. Test case: rm cs2103
      Expected: No module is deleted. Error details shown in the result window.

    4. Other incorrect delete commands to try: rm, rm x, ... (where x is an invalid module code)
      Expected: Similar to previous.

find: Finding modules by keyword or regex

  1. Finding modules that match the input keywords or input regex

    1. Prerequisites: Open CLIMods with stable internet connection

    2. Test case: find operating
      Expected: CG2271, CS2106, CS2106R, CS3221, CS5250, YSC3217 are listed. A success message of “6 modules listed!” should be displayed.

    3. Test case: find ^CS20\d0$
      Expected: CS2030, CS2040 are returned.
      A success message of “2 modules listed!” should be displayed.

Saving data

  1. Dealing with missing/corrupted data files

    1. Edit the local json save file and erase the saved folders till it is corrupted
    2. Launch the app
    3. CLIMods will not load the save file
    4. Adding mods will overwrite the corrupted file