Developer Guide

• Acknowledgements
• Setting up, getting started
• Design
  • Architecture
  • UI component
  • Logic component
  • Model component
  • Storage component
  • Common classes
• Implementation
  • [Proposed] Undo/redo feature
    • Proposed Implementation
    • Design considerations:
  • [Proposed] Data archiving
    • The Following UML Object Diagrams will illustrate how archive and load are done
  • Launch and shutdown
  • Deleting a person
  • Saving data

Acknowledgements

• {list here sources of all reused/adapted ideas, code, documentation, and third-party libraries – include links to the original source as well}

Setting up, getting started

Refer to the guide Setting up and getting started.

Design

Tip: The .puml files used to create diagrams in this document docs/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 (consisting of classes Main and MainApp) is in charge of the app launch and shut down.

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

The bulk of the app’s work is done by the following 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.

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

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 delete 1.

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

The UI consists of a MainWindow that is made up of parts e.g.CommandBox, ResultDisplay, PersonListPanel, 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. However, DialogBox inherits from HBox.

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 Person object residing in the Model.

CommandBox holds a reference towards AutocompleteParser which helps parses user input for a list of suggestions to show to the user.

Logic component

API : Logic.java

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

The sequence diagram below illustrates the interactions within the Logic component, taking execute("delete 1") API call as an example.

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

How the Logic component works:

1. When Logic is called upon to execute a command, it is passed to an AddressBookParser object which in turn creates a parser that matches the command (e.g., DeleteCommandParser) and uses it to parse the command.
2. This results in a Command object (more precisely, an object of one of its subclasses e.g., DeleteCommand) which is executed by the LogicManager.
3. The command can communicate with the Model when it is executed (e.g. to delete a person).
   Note that although this is shown as a single step in the diagram above (for simplicity), in the code it can take several interactions (between the command object and the Model) to achieve.
4. The result of the command execution is encapsulated as a CommandResult object which is returned back from Logic.

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 AddressBookParser 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 AddressBookParser 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 address book 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)

Note: An alternative (arguably, a more OOP) model is given below. It has a Tag list in the AddressBook, which Person references. This allows AddressBook to only require one Tag object per unique tag, instead of each Person needing their own Tag objects.

Storage component

API : Storage.java

The Storage component,

• can save both address book data and user preference data in JSON format, and read them back into corresponding objects.
• inherits from both AddressBookStorage 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)

The following is an example JSON output for a person:

{
    "name": "John Doe",
    "phone": "98765432",
    "gender": "male",
    "modules": [
        {
            "module": "CS2103T",
            "grade": 85
        }
    ],
    "tags": [
        "colleague"
    ]
}

Common classes

Classes used by multiple components are in the seedu.address.commons package.

Implementation

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

[Proposed] Undo/redo feature

Proposed Implementation

The proposed undo/redo mechanism is facilitated by VersionedAddressBook. It extends AddressBook with an undo/redo history, stored internally as an addressBookStateList and currentStatePointer. Additionally, it implements the following operations:

• VersionedAddressBook#commit() — Saves the current address book state in its history.
• VersionedAddressBook#undo() — Restores the previous address book state from its history.
• VersionedAddressBook#redo() — Restores a previously undone address book state from its history.

These operations are exposed in the Model interface as Model#commitAddressBook(), Model#undoAddressBook() and Model#redoAddressBook() respectively.

Given below is an example usage scenario and how the undo/redo mechanism behaves at each step.

Step 1. The user launches the application for the first time. The VersionedAddressBook will be initialized with the initial address book state, and the currentStatePointer pointing to that single address book state.

Step 2. The user executes delete 5 command to delete the 5th person in the address book. The delete command calls Model#commitAddressBook(), causing the modified state of the address book after the delete 5 command executes to be saved in the addressBookStateList, and the currentStatePointer is shifted to the newly inserted address book state.

Step 3. The user executes add n/David …​ to add a new person. The add command also calls Model#commitAddressBook(), causing another modified address book state to be saved into the addressBookStateList.

Note: If a command fails its execution, it will not call Model#commitAddressBook(), so the address book state will not be saved into the addressBookStateList.

Step 4. The user now decides that adding the person was a mistake, and decides to undo that action by executing the undo command. The undo command will call Model#undoAddressBook(), which will shift the currentStatePointer once to the left, pointing it to the previous address book state, and restores the address book to that state.

Note: If the currentStatePointer is at index 0, pointing to the initial AddressBook state, then there are no previous AddressBook states to restore. The undo command uses Model#canUndoAddressBook() to check if this is the case. If so, it will return an error to the user rather than attempting to perform the undo.

The following sequence diagram shows how an undo operation goes through the Logic component:

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

Similarly, how an undo operation goes through the Model component is shown below:

The redo command does the opposite — it calls Model#redoAddressBook(), which shifts the currentStatePointer once to the right, pointing to the previously undone state, and restores the address book to that state.

Note: If the currentStatePointer is at index addressBookStateList.size() - 1, pointing to the latest address book state, then there are no undone AddressBook states to restore. The redo command uses Model#canRedoAddressBook() to check if this is the case. If so, it will return an error to the user rather than attempting to perform the redo.

Step 5. The user then decides to execute the command list. Commands that do not modify the address book, such as list, will usually not call Model#commitAddressBook(), Model#undoAddressBook() or Model#redoAddressBook(). Thus, the addressBookStateList remains unchanged.

Step 6. The user executes clear, which calls Model#commitAddressBook(). Since the currentStatePointer is not pointing at the end of the addressBookStateList, all address book states after the currentStatePointer will be purged. Reason: It no longer makes sense to redo the add n/David …​ command. This is the behavior that most modern desktop applications follow.

The following activity diagram summarizes what happens when a user executes a new command:

Design considerations:

Aspect: How undo & redo executes:

• Alternative 1 (current choice): Saves the entire address book.
  • Pros: Easy to implement.
  • Cons: May have performance issues in terms of memory usage.
• Alternative 2: Individual command knows how to undo/redo by itself.
  • Pros: Will use less memory (e.g. for delete, just save the person being deleted).
  • Cons: We must ensure that the implementation of each individual command are correct.

{more aspects and alternatives to be added}

[Proposed] Data archiving

The archive and load feature is achieved through ArchiveCommand and LoadCommand which both extend the Command class. When such command is executed, the LogicManager will update the Storage when necessary.

The Following UML Object Diagrams will illustrate how archive and load are done

Before the archiving or loading

We will use a simple case where there is one working AddressBook named addressBook.json in data folder and one archived AddressBook named archivedFile1.json in archived folder

Scenario 1 Archive to a new file

In this scenario, the user is trying to archive the current address book into a new file named archiveFile2.json. He enters the command archive pa/archiveFile2.json A new file names archiveFile2.json will be created and hold the data of addressBook.json. And the data in addressBook.json will be discarded.

Scenario 2 Archive to a existing file

In this scenario, the user is trying to archive the current address book into the existing file named archiveFile1.json. He enters the command archive pa/archiveFile1.json A file names archiveFile1.json will be overwritten and hold the data of addressBook.json. And the data in addressBook.json will be discarded.

The following sequence diagram illustrate how an archive operation is processed under Logic component.

Note: The lifeline for ArchiveCommand should end at the destroy marker (X) but due to a limitation of PlantUML, the lifeline reaches the end of diagram. Some details like parameters of function is omitted for simplicity. Scenario 3 Loading from a file In this scenario, the user is trying to load the an address book from a file named archiveFile1.json. He enters the command load pa/archiveFile1.json. The data in the current working address book will be discarded. The data in archiveFile1.json will be loaded into the working address book. The following sequence diagram illustrate how an archive operation is processed under Logic component.

Note: The lifeline for LoadCommand should end at the destroy marker (X) but due to a limitation of PlantUML, the lifeline reaches the end of diagram. Some details like parameters of function is omitted for simplicity. ——————————————————————————- ## Documentation, logging, testing, configuration, dev-ops * Documentation guide * Testing guide * Logging guide * Configuration guide * DevOps guide ——————————————————————————————————————– ## Appendix: Requirements ### Product scope Target user profile: * a teacher in an educational institution (private institution, i.e. tuition centers) * need to manage large amount of student information * prefer desktop apps over other types * can type fast * prefers typing to mouse interactions * is reasonably comfortable using CLI apps Value proposition: It allows for easy and efficient retrieval or storage of student information while providing a clean and user-friendly interface. The application supports modularity, and users are able to import and export to other similar applications without relying on complex or costly software. ### User stories Priorities: High (must have) - * * *, Medium (Good to have) - * *, Low (nice to have) - * | Priority | As a …​ | I want to …​ | So that I can…​ | |———-|———-|———————————————————–|—————————————————————-| | * * * | educator | add students into the database | easily refer to their information when needed | | * * * | educator | list all students to view the number of students | collate that information | | * * * | educator | delete a student | remove entries that I no longer need | | * * * | educator | find a person by name | find the relevant person without scrolling through a long list | | * * | educator | clear all information | start anew for a new academic year | | * * | educator | update details easily when there are changes | have the most updated information | | * * | educator | categorize students into groups | | | * * | educator | record students grades for tests and assignments | | | * * | educator | view a summary of each student’s grade | | | * * | educator | tag students with relevant labels | prioritize students based on their status | | * * | educator | record notes on student behaviour | easily track issues related to their behaviour | | * * | educator | archive old student data | keep my AB clean while being able to retrieve old information | | * | educator | set learning goals | track their progress towards these goals | | * | educator | undo/redo any changes | avoid re-entering the data during a mis-entry | | * | educator | see a list of suggested commands when typing out commands | easily type in the commands that I want and reduce typos | | * | educator | export student data | share the information with others | | * | educator | keep track of meetings with students | keep track of my commitments | | * | educator | see sample data | try out the app’s feature without adding my own student data | ### Use cases (For all use cases below, the System is the StoreClass and the Actor is the user, unless specified otherwise) #### Use case 1: List out all students Main Success Scenario 1. User requests to list students 2. StoreClass shows a list of students Use case ends. #### Use case 2: Delete a student Main Success Scenario 1. User requests to list students 2. StoreClass shows a list of students 3. User requests to delete a specific student in the list 4. StoreClass deletes the student Use case ends. Extensions * 2a. The list is empty. Use case ends. * 3a. The given index is invalid. * 3a1. AddressBook shows an error message. Use case resumes at step 2. #### Use case 3: Add a student Main Success Scenario 1. User requests to add persons and type in the relevant information 2. StoreClass adds the new student 3. StoreClass show the new list of students Use case ends. Extensions * 1a. The provided information is invalid. * 1a1. StoreClass displays the corresponding data error message. Use case resumes at step 1. #### Use case 4: Search for student Main Success Scenario 1. User requests to search for student with the relevant search query. 2. StoreClass displays the relevant student(s) matching the query.
Use case ends. Extensions * 1a. StoreClass is unable to find any matching results. * 1a1. StoreClass displays a message indicating that not students match the search query. Use case ends. #### Use case 5: Update Student Information Main Success Scenario 1. User requests to list students (UC1). 2. User selects the specific student from the list to update. 3. User enters the new information. 4. StoreClass updates the student’s details and display a success message. </br> Use case ends. Extensions * 4a. StoreClass detects an error in the entered information. * 1a1. StoreClass displays a message indicating which fields are invalid. Use case ends. #### Use case 6: Record Student Grades Main Success Scenario 1. User requests to list students (UC1). 2. User selects the specific student to record a grade. 3. User enters the grade information. 4. StoreClass updates the student’s grades and display a success message. </br> Use case ends. Extensions * 4a. StoreClass detects an error in the entered information. * 1a1. StoreClass displays a message indicating which fields are invalid. Use case ends. #### Use case 7: Categorize Students Main Success Scenario 1. User requests to list students (UC1). 2. User selects one or more students to be categorized. 3. StoreClass requests for the group to assign the students to. 4. User selects the group. 5. StoreClass categorize the student(s) and display a success message. </br> Use case ends. Extensions * 4a. StoreClass detects that no groups exist. * 4a1. StoreClass allows the user to create a new group. * 4a2. StoresClass creates a new group. Use case resumes from step 6. #### Use case 8: Tag Students Main Success Scenario 1. User requests to list students (UC1). 2. User selects one or more students to be tagged. 3. StoreClass requests for the tag(s) to assign the students to. 4. User enters the tag(s) 5. StoreClass applies the tags to the selected student(s) and display a success message. </br> Use case ends. Extensions * 4a. StoreClass detects an invalid tag(s). * 4a1. StoreClass requests a valid tag. * 4a2. User enters a valid tag. </br> Steps 4a1-4a2 are repeated until a valid tag is entered. </br> Use case resumes from step 6. #### Use case 9: Archive Student Data Main Success Scenario 1. User requests to archive student data. 2. StoreClass requests confirmation for archiving. 3. User confirms. 4. StoreClass archives the students data and removes them from the current interface. 5. StoreClass displays a success message. </br> Use case ends. Extensions * a. User wishes to view the archived data. * *a1. StoreClass lists all available archives. * *a2. User selects the archive. * *a3. StoreClass displays the archives information. Use case ends #### Use case 10: Export Student Data Main Success Scenario 1. User chooses to export student data. 2. StoreClass requests confirmation for exporting. 3. User confirms. 4. StoreClass exports the students data and displays a success message. </br> Use case ends. Extensions * *4a. StoreClass is unable to export the data. * *4a1. StoreClass returns an error message. Use case ends. #### Use case 11: Undo/Redo Actions Main Success Scenario 1. User performs an action/command. 2. User chooses to undo the action. 3. StoreClass reverses the action and displays a success message. </br> Use case ends. Extensions * *a. User chooses to redo the action. * *a1. StoreClass restores the previous action and display a success message. Use case ends. ### Non-Functional Requirements 1. Should work on any _mainstream OS_ as long as it has Java 17 or above installed. 2. Should be able to hold up to 1000 persons without a noticeable sluggishness in performance for typical usage. 3. A user with above average typing speed for regular English text (i.e. not code, not system admin commands) should be able to accomplish most of the tasks faster using commands than using the mouse. 4. The product should be an offline product that can run without accessing the internet, allowing access to core features such as adding, deleting, listing and archiving. 5. Sensitive student data such as contact details, grades and payment information should be protected through encryption or password protection to prevent unauthorized access. 6. The system should be able to manage an increasing number of students and additional data fields without significant performance degradation, ensuring that response times remains under 200ms. ### Glossary * Archive: A feature that allows users to store old data for use later without cluttering the current interface. * Export: Saving the student data in a file format such as .csv or .txt for external use. * Private contact detail: A contact detail that is not meant to be shared with others * Mainstream OS: Windows, Linux, Unix, MacOS * Student Number: A unique identifier assigned to each student. * Tag: A label that can be added to a student for categorization or searching. * Undo/Redo: The ability to reverse an action/command made in the application. ——————————————————————————————————————– ## Appendix: Instructions for manual testing Given below are instructions to test the app manually.

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

Launch and shutdown

1. Initial launch

   1. Download the jar file and copy into an empty folder

   2. Double-click the jar file Expected: Shows the GUI with a set of sample contacts. The window size may not be optimum.

2. Saving window preferences

   1. Resize the window to an optimum size. Move the window to a different location. Close the window.

   2. Re-launch the app by double-clicking the jar file.
      Expected: The most recent window size and location is retained.

3. { more test cases …​ }

Deleting a person

1. Deleting a person while all persons are being shown

   1. Prerequisites: List all persons using the list command. Multiple persons in the list.

   2. Test case: delete 1
      Expected: First contact is deleted from the list. Details of the deleted contact shown in the status message. Timestamp in the status bar is updated.

   3. Test case: delete 0
      Expected: No person is deleted. Error details shown in the status message. Status bar remains the same.

   4. Other incorrect delete commands to try: delete, delete x, ... (where x is larger than the list size)
      Expected: Similar to previous.

2. { more test cases …​ }

Saving data

1. Dealing with missing/corrupted data files

   1. {explain how to simulate a missing/corrupted file, and the expected behavior}

2. { more test cases …​ }