Developer Guide

• Acknowledgements
• Setting up, getting started
• Design
  • Architecture
  • UI component
  • Logic component
  • Model component
  • Storage component
  • Common classes
• Implementation
  • Add feature (modification of existing feature)
    • Implementation Details
    • Design Considerations
  • Event feature
    • Implementation Details
    • Design considerations
  • Chain commands feature
    • Implementation Details
    • Design considerations
  • Clear feature improvements
    • Implementation details
    • Design considerations:
  • Save events to Json format
    • Implementation details
    • Design considerations
  • [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
• Appendix: Instructions for manual testing
  • Launch and shutdown
  • Adding a person
  • Deleting a person
  • Renaming an event
  • Removing a person from an event
  • 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 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 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, 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 and Event object residing in the Model.
• within the PersonListPanel, either PersonCard is displayed or PersonDetailsCard exclusively.
• the PersonCard and PersonDetailsCard depends on Model.
• within the EventListPanel, EventCard is displayed.
• the EventCard depends on Model.
• the EventCard also reuses PersonListPanel from the UI components related to the member tab, hence the association.

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 AddressBookParser class to parse the user command.
2. This results in a Command object (more precisely, an object of one of its subclasses e.g., AddCommand) which is executed by the LogicManager.
3. The command can communicate with the Model when it is executed (e.g. to add a person).
4. The result of the command execution is encapsulated as a CommandResult object which is returned back from Logic.

The Sequence Diagram below illustrates the interactions within the Logic component for the execute("delete 1") API call.

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) and all Event objects (which are contained in a UniqueEventList 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 the currently ‘selected’ Event objects (e.g., results of a search query) as a separate filtered list which is exposed to outsiders as an unmodifiable ObservableList<Event> 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)
• the Person package contains classes related to the Person class.
• the Person class contains:
  • Name
  • Phone
  • Telegram
  • Email
  • Tag
• the UniquePersonList contains a unique list of Person objects.
• the Event package contains classes related to the Event class.
• the Event class contains:
  • EventName
  • UniquePersonList as the list of attendees
• the UniqueEventList contains a unique list of Event 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)

Common classes

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

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Implementation

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

Add feature (modification of existing feature)

Implementation Details

The add feature is implemented as a command such that it follows the flow of the Logic component as outlined above. The feature was modified to allow the user to omit non-essential details when adding a person (Phone, Telegram, Email, Tag(s)). These changes are reflected in the updated Model Class Diagram. This was done by taking the approach of using a unique unspecified input for omitted details. Through such an approach, the modification to existing code was minimised.

Design Considerations

Aspect: Ensuring that validation regex still valid.

• Alternative 1 (current choice): Bypass the validation regex check since unspecified input does not require to be checked.
  • Pros: Does not require unnecessary modification of the validation regex.
  • Cons: Requires an additional check for whether it is an unspecified input. This con was mitigated by extracting out the check to ensure code is SLAP and in a single level of abstraction.
• Alternative 2: Modify validation regex to match unspecified input string.
  • Pros: Does not require the additional lines of code, may be seen as a “cleaner” implementation.
  • Cons: Validation regex would become much more complex and unreadable. Also makes the code less extensible for other developers who may want to change the unspecified input string.

Event feature

Implementation Details

The event feature is implemented in AddressBook by having AddressBook maintain a UniqueEventList. The implementation is similar to how Person is implemented in AddressBook. The relevant UI components then displays the events in an EventCard within the EventListPanel.

As a result, AddressBook now has the following additional methods.

• setEvents(List<Events>)
• hasEvent(Event)
• addEvent(Event)
• setEvent(Event, Event)
• removeEvent(Event)
• clearAllEvents()
• getEventList()

The Model interface now has the following additional methods.

• hasEvent(Event)
• deleteEvent(Event)
• clearAllEvent()
• addEvent(Event)
• setEvent(Event, Event)
• getFilteredList()
• updateFilteredLisst(Predicate<Event>)

The way Event behaves is very similar to Person and thus will be omitted to reduce repeated details.

Design considerations

Aspect: Whether to generify UniqueEventList:

• Alternative 1 (current choice): Create a UniqueEventList class similar to UniquePersonList.
  • Pros: Easy to implement since there is already a reference. Can get code out fast.
  • Cons: Lots of boilerplate code
• Alternative 2: Generify UniqueEventList and UniquePersonList.
  • Pros: Much more elegant, extensible.
  • Cons: Needs major changes to existing code, risks regressions. Need to change multiple methods name like setPerson to setItem.

We have decided to go ahead with Alternative 1 as it is easier to implement due to time constraints. Alternative 1 is likely to be more reliable as we do not risk running into regressions as much. While Alternative 1 is less extensible, since we are only creating 1 more class of this type, the pros seems to outweigh the cons.

Aspect: Whether to generify Name, reuse Name or create EventName:

• Alternative 1 (current choice): Create EventName class similar to Name.
  • Pros: Easy to implement, since we already have similar code. Less likely to introduce regressions.
  • Cons: More boilerplate code.
• Alternative 2: Reuse Name class.
  • Pros: Nothing to implement, lesser things to test.
  • Cons: Unable to have different type of valid name checking.
• Alternative 3: Make Name class generic, depending on the type of predicate used to test if name is valid.
  • Pros: Much more general. Lesser things to test, lesser bugs when done correctly.
  • Cons: Hard to implement. Over engineering.

We have decided to go ahead with Alternative 1 as it allows for greater flexibility for future changes. The validity of an EventName does not have to follow that of Name and thus Alternative 1 would be ideal for such a case. Moreover, using a different class allows for type checking, which ensures we do not accidentally pass a Name belonging to a Person to a method expecting EventName belonging to an Event.

Chain commands feature

Implementation Details

The Chain Commands feature is implemented in AddressBookParser as a type of Command with similar implementations to how other commands are executed.

As such a new regex expression is created in AddressBookParser besides looking for the current BASIC_COMMAND_FORMAT and will search for commands with ADVANCED_COMMAND_FORMAT.

If a command matches the ADVANCED_COMMAND_FORMAT it will then parse the command into a ChainCommand which when executed will execute the two commands parsed into it.

The following sequence diagram shows how the Chain command parsing and execution works:

Design considerations

Aspect: How to parse inputs given to ChainCommand:

• Alternative 1 (current choice): Handle the parsing of the inputs within AddressBookParser itself.
  • Pros: Easy to implement with no new classes created.
  • Cons: Creates an additional condition before basic commands are parsed. Making it difficult to trace the regular functioning of basic commands.
• Alternative 2: Use a ChainCommandParser and Command Words
  • Pros: The structure of how commands are usually executed is preserved, making code tracing easier to do.
  • Cons: Unable to parse the inputs of the ChainCommand without passing the current AddressBookParser object into the parser. Which will change the inputs of the Parser.

We have decided to go ahead with Alternative 1 as it preserves the current implementation of the Parser and avoid having to pass around AddressBookParser objects during run time. While the code is modified instead of extended, we believe that the alternative will cause even more modifications in the future resulting in futher problems.

Clear feature improvements

Implementation details

As there are two separate lists (member and event list), we need a way to properly separate operations on either of the two list.

Hence, this calls for flags in the command. There are two flags in the CliSyntax: -p for person (member) and -e for event. Also, there is a new Parser implemented for the clear command to check for the validity of the command as well as deciding which list the clear command should operate on.

The following sequence diagram shows how the clear command parsing and execution works:

Design considerations:

Aspect: How to clear entries in the given range

• Alternative 1 (current choice): Reuse the deletePerson and deleteEvent. A loop is used in the ClearCommand from the ending index to the beginning index.
  • Pros: Easier to implement with no new methods introduced to the Model component. Furthermore, the two methods used are properly tested.
  • Cons: lengthy implementation (using loops)
• Alternative 2: Create two new methods deleteAllPerson and deleteAllEvent in Model to facilitate this enhancement.
  • Pros: A simpler, more direct way of implementing this enhancement. ClearCommand will simply call the appropriate command depending on the flag given.
  • Cons: Requires additional testing to ensure that the two new methods function correctly. There is also a possibility of the methods clashing with the implementation of the UI component.

Save events to Json format

Implementation details

A new class JsonAdaptedEvent is implemented. The JsonSerializableAddressBook now stores both JsonAdaptedPerson and JsonAdaptedEvent A JsonAdaptedEvent instance may contain multiple instances of JsonAdaptedPerson, which are the details of the members participating in that event.

Design considerations

Aspect: How to store the list of persons participating in a particular event

• Alternative 1 (current choice): JsonAdaptedEvent will store a list of JsonAdaptedPerson
  • Pros: Easy to implement. This implementation is similar to how the JsonSerializableAddressBook stores JsonAdaptedPerson in AB3.
  • Cons: Overhead in data stored. Data of the same person may be repeated in the save file.
• Alternative 2: JsonAdaptedEvent will store the every index in the members’ list of the members participating in the event
  • Pros: Less overhead in data stored
  • Cons: Updating the person list will require updates to every single entry in the event list since the index of every entry is changed. Furthermore, this implementation is very hard to test.

[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 the undo operation works:

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:

• has a need to manage a significant number of members for his CCA or interest group
• prefer desktop apps over other types
• can type fast
• prefers typing to mouse interactions
• is reasonably comfortable using CLI apps

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

User stories

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

Priority	As a …​	I want to …​	So that I can…​
* * *	user	add new members with details	track my members
* * *	user	delete a member	remove members who are not active anymore
* * *	user	view a member’s detail
* *	first time user	easily find the details of available commands	learn new commands
* *	first time user	easily populate the application with dummy data	try out features and see how the application is used
* *	first time user	easily clear all data	remove unneeded data and start the application afresh
* *	new user	see new tip on features and commands	get to know the application better
* *	new user	undo my commands	easily undo mistakes
* *	interest group leader	search and filter member	find selected members easily
*	expert user	type commands in one line	execute commands quickly
*	expert user	chain commands together and write macros	increase my productivity
*	user	tag an event or training session to a person	keep track of their attendance and contact them easily if they have not arrived

Use cases

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

Use case: UC01 - Add a new member into the system

MSS

1. User wants to add a new member.
2. User enters the details of the new member, which are name, phone number, telegram handle and email.

3. System confirms that the member is added.

   Use case ends.

Extensions

• 2a. System detects that the name is not entered.
  • 2a1. System requests for the name to be entered.
  • 2a2. User enters the name of the new member.
  • Step 2a1-2a2 are repeated until the name is entered.
• 2b. System detects that the phone number is not entered.
  • 2b1. System accepts that the phone number is not entered as it is optional.
  • Use case resumes at 2c.
• 2c. System detects that the telegram handle is not entered.
  • 2c1. System accepts that the telegram handle is not entered as it is optional.
  • Use case resumes at 2d.
• 2d. System detects that the email is not entered.
  • 2d1. System accepts that the email is not entered as it is optional.
  • Use case resumes at 3.

Use case: UC02 - Delete a member from the system

MSS

1. User searches for a member using UC04 - Find a member.
2. User requests to delete the member.

3. System confirms that the member is deleted.

   Use case ends.

Extensions

• 2a. User attempts to delete a member that is not in the list.
  • 2a1. System notifies the user that the member is not in the list.

  Use case ends.

Use case: UC03 - View all members managed by the system

MSS

1. User requests to view all members managed by the system.

2. System shows a list of all members managed by the system.

   Use case ends.

Use case: UC04 - Find a member

MSS

1. User requests to find members with a given keyword.

2. Members with details matching the given keywords are shown in the same format as UC03 - View all members managed by the system.

   Use case ends.

Extensions

• 1a. User enters empty keyword

  • 1a1. System informs user that keyword cannot be empty

    Use case ends.

Use case: UC05 - View the details of members

Guarantees: All details previously entered are displayed

MSS

1. User requests to see the details of a certain member.
2. All details regarding the specified member are shown. Use case ends.

Extensions

• 1a. User enters the name of a member who does not exist in the current list of members
  • 1a1. Application is unable to find the user specified.
  • 1a2. Application displays message to inform user than member specified does not exist.

  Use case ends.

Use case: UC06 - Clear past data

Guarantees: All member data are cleared

MSS

1. User requests to delete member data.
2. All member data is deleted.

3. System confirms that past data has been deleted.

   Use case ends.

Extensions

• 2a. System is unable to delete data.
  • 2a1. System notifies the user of the reason why it is not able to delete the data.

Use case: UC07 - Exit the application

MSS

1. User is done using the app and requests to exit the app.

2. Application exits.

   Use case ends.

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 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.

Glossary

• Address Book: An address book is a database used for storing contacts
• Mainstream OS: Windows, Linux, Unix, OS-X
• Private contact detail: A contact detail that is not meant to be shared with others
• Interest Group (IG): A student run organisation which focuses on a common interest (such as sports, games, etc). Similar to co-curricular activities (CCAs) in Secondary School or Junior College.
• IG: Interest Group
• RC: Residential College
• Halls: Halls of Residence
• CCA: Co-Curricular Activity
• Telegram handle: Telegram username

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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 …​ }

Adding a person

1. Adding a new person to the address book.

   1. Test case: add n/John Doe
      Expected: First person is added to the list. Details of the added person shown in the status message. Timestamp in the status bar is updated.

   2. Test case: add n/John Smith p/98765432 e/johnd@example.com t/@johndoedoe tag/friends tag/owesMoney
      Expected: Second person is added to the list. Tags are displayed under the person’s name. Details of the added person shown in the status message. Timestamp in the status bar is updated.

   3. Test case: omit optional details (phone number, email, telegram, tags)
      Assumption: Name is provided and person is not a duplicate. Expected: Person is added to the list. Details of the added person shown in the status message. Omitted details are replaced by the placeholder message: “NIL: No [omitted detail] specified”.

   4. Test case: add n/John Smith
      Expected: No person is added. Duplicate person error details shown in status bar.

   5. Test case: add p/98765432
      Expected: No person is added. Invalid command format error shown in status bar.

2. { 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 …​ }

Renaming an event

1. Rename an existing event in the address book.

   1. Test case: renameEvent 1 ev/NewName
      Expected: Name of the first event in the event list changes to “NewName”. List of attendees remains the same.

   2. Test case: renameEvent ev/NewName
      Expected: No event name is changed. Invalid command format shown in status bar.

   3. Test case: renameEvent 1
      Expected: No event name is changed. Invalid command format shown in status bar.

Removing a person from an event

1. Removes a specified person from a specified event in the address book.

   1. Prerequisites: The event “Party” exists. The “Party” contains an attendee with the name “John Doe”. An event with the name “Dinner” does not exist.

   2. Test case: removePersonFromEvent n/John Doe ev/Party
      Expected: John Doe is removed from the “Party” event’s list. Details of the removal show in status bar.

   3. Test case: removePersonFromEvent n/John Doe
      Expected: No change. Invalid command format shown in status bar.

   4. Test case: removePersonFromEvent ev/Party
      Expected: No change. Invalid command format shown in status bar.

   5. Test case: removePersonFromEvent n/John Doe ev/Dinner
      Expected: No change. Event not found error message shown in status bar.

   6. Test case: removePersonFromEvent n/John Doe ev/Party
      Note: John Doe no longer exists in this event’s list due to test case ii. Expected: No change. Person not found error message shown in status bar.

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 …​ }