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
• Documentation, logging, testing, configuration, dev-ops
• Appendix: Requirements
  • Product scope
  • User stories
  • Use cases
  • Non-Functional Requirements
  • Glossary
• Validation rule: A constraint that ensures inputs (e.g., date, phone number, email) are correct before the system accepts them.
• Appendix: Instructions for manual testing
  • Launch and shutdown
  • Deleting a person
  • Saving data

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Acknowledgements

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

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Setting up, getting started

Refer to the guide Setting up and getting started.

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Design

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.

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.

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.

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)

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)

Common classes

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

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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.

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.

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

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.

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

{Explain here how the data archiving feature will be implemented}

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Documentation, logging, testing, configuration, dev-ops

• Documentation guide
• Testing guide
• Logging guide
• Configuration guide
• DevOps guide

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Appendix: Requirements

Product scope

Target user profile:

• Profession: Social workers in Singapore who handle 20–50 clients at once.
• Work habits: Prefer desktop-based tools, comfortable with fast typing and CLI-style interactions, value speed over graphical interfaces.
• Needs: Quick access to client information, efficient management of multiple contacts, and reduced administrative burden.
• Pain points: High workload, administrative overload, and stress from juggling paperwork, cultural complexities, and deadlines.

Value proposition: Social workers manage dozens of clients at once. HeartLink provides fast and convenient access to client contact details while helping track workload. By reducing the burden of administrative tasks, remembering check-ins, and organizing deadlines across scattered records, our address book minimizes paperwork stress and allows social workers to focus on supporting the people who need them.

User stories

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

Priority	As a …​	I want to …​	So that I can…​
* * *	social worker	add a new client’s information	access information of the client when I need it
* * *	social worker	view a client’s contact information	contact them when necessary
* * *	social worker	edit client information	keep the information up to date
* * *	social worker	delete a client	clean up my contacts in the address book
* * *	social worker	link appointments to each client	keep track of when my appointments are for each client
* *	new social worker user	see usage instructions	refer to instructions when I forget how to use the app
* *	social worker	search/find a client by name	locate details quickly without scrolling
* *	social worker	receive notifications for meetings	not miss them and stay organized before the meeting
* *	social worker	add remarks/notes	remember who this client is
* *	social worker	sort my appointments by priority	find my most urgent appointments easily
* *	mobile social worker	group the clients I have to visit	streamline my workflow
* *	social worker	sort clients by distance	plan my route for the day
* *	social worker	add a client’s picture	confirm the appearance of the client
* *	visual social worker	see all my appointments on a calendar	visualize how busy my schedule will be
* *	social worker	see all my appointments in a list view	have a simple overview
* *	caring social worker	pin important contacts	focus more on those who need my help
* *	clumsy social worker	search clients without exact spelling	find clients even if I don’t remember their exact name
* *	social worker	backup client information	recover client information in case of mistakes or accidental deletion
* *	busy social worker	have a system that is easy to use	not spend too much time figuring it out
*	lazy social worker	delete multiple clients in one shot	save time instead of deleting one by one
*	stressed social worker	select an option to view important appointments	avoid being overwhelmed by workload, reducing stress
*	social worker	archive a client	find contacts again in the future if needed
*	impatient social worker	nuke all contacts	vent my anger
*	impatient social worker	recover all contacts after nuking	restore everything if I make a mistake
*	sad social worker	find my therapist fast	get some help
*	social worker who travels	use the app without internet	still use it in places with bad signal
*	social worker without phone	use the app for other communication	still link up with my clients
*	social worker	have a shortcut to call police	seek help when a client abuses me
*	less tech-savvy worker	have easy access to an application guide	learn how to use it without frustration
*	social worker	have a system that works reliably	ensure wrong commands don’t destroy the address book

{More to be added}

Use cases

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

Use case: Add a client

MSS

1. User requests to add client

2. HeartLink adds the client to the list.

   Use case ends.

Extensions

• 1a. The given details were incomplete.

  • 1a1. HeartLink shows error message.

    Use case ends.

• 1b. The given name/phone number/email already exists.

  • 1b1. HeartLink shows an error message.

    Use case ends.

• 1c. The given details are of an invalid syntax.

  • 1c1. HeartLink shows an error message.

    Use case ends.

Use case: Edit client information

MSS

1. User requests to view clients.
2. HeartLink shows a list of clients
3. User requests to edit a specific person in the list

4. HeartLink edits the specified details of the clients.

   Use case ends.

Extensions

• 2a. The list is empty.

  Use case ends.

• 3a. The given name does not exist.

  • 3a1. HeartLink shows an error message.

    Use case resumes at step 2.

• 3b. The updated name/phone number/email already exists.

  • 3b1. HeartLink shows an error message.

    Use case resumes at step 2.

• 3c. The given details are of invalid syntax.

  • 3c1. HeartLink shows an error message.

    Use case resumes at step 2.

Use Case: Link Appointment to Client

MSS

1. User requests to view clients.
2. HeartLink shows a list of clients.
3. User requests to link an appointment to a specific client with the relevant details.
4. HeartLink creates the appointment and links it to the chosen client.

Use case ends.

Extensions

• 2a. No clients available

  • 2a1. HeartLink shows an empty list.

    Use case ends.

• 3a. Specified client does not exist

  • 3a1. HeartLink shows an error message.

    Use case resumes at step 2.

• 3b. Appointment details are invalid (date, time, duration, or status)

  • 3b1. HeartLink shows an error message.

    Use case resumes at step 2.

• 3c. Appointment conflicts with an existing one

  • 3c1. HeartLink shows a scheduling conflict message.

    Use case resumes at step 2.

• 3d. Appointment duplicates an existing one

  • 3d1. HeartLink shows a duplicate appointment error.

    Use case resumes at step 2.

Use case: View clients

MSS

1. User requests to list of clients.
2. User provides additional attributes to filter by, such as name, appointment date, tag, and rank.

3. HeartLink displays the list of all clients corresponding to the attributes given by a user. All information for each person are shown.

   Use case ends.

Extensions

• 2a. The given request is syntactically incorrect.

  • 2a1. HeartLink shows an error message.

    Use case resumes at step 1.

• 2b. One of the fields are invalid.

  • 2b1. HearLink shows an error message.

    Use case resumes at step 1.

Non-Functional Requirements

1. Compatibility Our system should work on any mainstream OS as long as it has Java 17 or above installed.
2. Performance Our system should be able to hold up to 1000 persons without a noticeable sluggishness in performance for typical usage.
3. User Experience 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. User Experience The client list view shall display no more than 5–6 clients per screen, with scrolling enabled to access additional entries, to avoid information overloading.
5. User Experience Our system should limit the amount of text displayed to prevent lags and UI issues. It should also gracefully handle text-related issues such as long strings, emoji rendering, and font compatibility.
6. Process Requirement Our project is expected to adhere to a schedule that delivers a feature set every week throughout the second half of the semester.
7. Quality Assurance All source code shall achieve a minimum of 80% unit test coverage.

Glossary

• Mainstream OS: Windows, Linux, Unix, MacOS
• Appointment: A scheduled event linked to a client, with details such as date, time, duration, location, type, notes, and status.
• Appointment status: The progress state of an appointment — planned, confirmed, completed, or cancelled.
• Ambiguity error: An error shown when multiple clients match the same name.
• Client: An individual whose information, appointments, and notes are managed in HeartLink.
• Conflict detection: A rule that prevents overlapping appointments for the same client.
• Contact information: Details that allow communication with a client, such as phone number, email, or address.
• Duplicate entry: An error condition where an identical client or appointment already exists.
• Orphan appointment: An appointment that is not linked to any client (not allowed in HeartLink).
• Person list: The collection of all clients currently stored in HeartLink.
• Scheduling conflict: A clash where two appointments for the same client overlap in time.

• Validation rule: A constraint that ensures inputs (e.g., date, phone number, email) are correct before the system accepts them.

Appendix: Instructions for manual testing

Given below are instructions to test the app manually.

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 …​ }