Developer Guide

• Acknowledgements
• Setting up, getting started
• Design
  • Architecture
  • UI component
  • Logic component
  • Model component
  • Storage component
  • Common classes
• Implementation
  • Sort feature
  • Find feature
  • [Proposed] Undo/redo feature
    • Proposed Implementation
    • Design considerations:
• Documentation, logging, testing, configuration, dev-ops
• Appendix: Requirements
  • Product scope
  • User stories
  • Use cases
  • Non-Functional Requirements
  • Glossary
• Appendix: Planned Enhancements
• Appendix: Sorted List Bug
• Appendix: Instructions for manual testing
  • Launch and shutdown
  • Adding a person
  • Editing a person
  • Finding a person
  • Deleting a person
  • Saving data

Acknowledgements

Clientele+ is developed based on the AddressBook Level-3 application. Learn more about that project here.

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 are in the 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 id/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 id/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 archived 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 the currently ‘selected’ Person objects (e.g. after an archive command) as a separate filtered list which is exposed to outsiders as an unmodifiable ObservableList<Person> that can be ‘observed’ e.g. the UI is bound to this list when the command to access the archived list is entered.
• 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. This is the same for ArchivedAddressBook as well.

Storage component

API : Storage.java

The Storage component,

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

Implementation

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

Sort feature

The following sequence diagram shows how a sort command goes through the Model component:

Find feature

The following sequence diagram shows how a find command goes through the Model component:

[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 id/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 id/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:

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.

Documentation, logging, testing, configuration, dev-ops

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

Appendix: Requirements

Product scope

Target user profile:

• Needs to manage a variety of sections, such as client names, email, payment status and more.
• Desire to track all client statuses in one place.
• Wants to avoid tracking clients using multiple applications.
• Wants to easily change statuses of a client upon completion of project.
• Can type fast (≥80 wpm).
• Prefers typing over mouse interactions.
• Familiar with the workings of CLI and commands.

Value proposition: Clientele+ seamlessly combines client contacts, payment tracking and more in one efficient package, tailored specifically for freelance software developers.

User stories

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

Use cases

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

Use case: Add a client

MSS

1. User provides client details to add.

2. Clientele+ adds the client.

   Use case ends.

Extensions

• 1a. The client’s name, phone, email, address, or deadline is not provided.

  • 1a1. Clientele+ shows an error message.

  • 1a2. User reenters new command.

    Steps 1a1-1a2 are repeated until the command entered is correct.

    Use case resumes from step 1.

• 1b. Input fields are incorrectly formatted.

  • 1b1. Clientele+ shows an error message.

  • 1b2. User reenters command.

    Steps 1b1-1b2 are repeated until the command entered is correct.

    Use case resumes from step 1.

• *a. At any time, user decides to stop adding the client, or exits the application.

  • *a1. Nothing is added to the client list.

    Use case ends.

Use case: Delete a client

MSS

1. User requests to list persons.
2. Clientele+ shows a list of persons.
3. User requests to delete a specific client in the list.

4. Clientele+ deletes the client.

   Use case ends.

Extensions

• 2a. The list is empty.

  • 2a1. Clientele+ shows an error message.

    Use case ends.

• 3a. The given index or name is invalid.

  • 3a1. Clientele+ shows an error message.

    Use case resumes from step 2.

• 3b. Multiple names matching the given name exist.

  • 3b1. Clientele+ shows list of clients with matching names.

  • 3b2. Clientele+ prompts user to delete by index.

    Use case resumes from step 3.

• *a. At any time, user decides to stop deleting the client, or exits the application.

  • *a1. Nothing is deleted from client list.

    Use case ends.

Use case: Modify a client’s details

MSS

1. User requests to list persons.
2. Clientele+ shows a list of persons.
3. User selects the client they wish to modify and provides the updated details.

4. Clientele+ updates that client’s details.

   Use case ends.

Extensions

• 2a. The list is empty.

  • 2a1. Clientele+ shows an error message.

    Use case ends.

• 3a. The selected index is invalid.

  • 3a1. Clientele+ shows an error message.

    Use case resumes from step 2.

• 3b. The given details are invalid.

  • 3b1. Clientele+ shows an error message.

    Use case resumes from step 2.

Use case: Find a client

MSS

1. User provides search parameters.

2. Clientele+ shows a list of persons matching the parameters.

   Use case ends.

Extensions

• 1a. Search parameters are incorrectly formatted.

  • 1a1. Clientele+ shows an error message.

  • 1a2. User reenters command.

    Steps 1a1-1a2 are repeated until the command entered is correct.

    Use case resumes from step 1.

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. A user should be able to accomplish all tasks just through typing commands (so no clickable buttons for instance).
5. Command usage and help messages should be clear enough to a user with at least some CLI experience.
6. The window must look good on a screen that has a resolution of 980x720 or higher (i.e. lines must not bleed out of the window edge).
7. A more technical user must be able to interpret the contents of the stored JSON file.
8. A user must be updated on the status of their command within (at most) 2 seconds.

Glossary

• API: A set of functions that enable communication between software components.
• fxml: File format used to format/structure a JavaFX application’s UI.
• JavaFX: A third-party software for Java, used to run our builds and tests.
• Mainstream OS: Windows, Linux, Unix, MacOS
• Parser: The software component responsible for interpreting user input into commands.
• PlantUML: A third-party tool that facilitates the creation of various software diagrams.
• Versioned AddressBook: An extension to the AddressBook class that allows undoing/redoing actions.

Appendix: Planned Enhancements

Note: Our team size is 5

1. Make the GUI wrap large addresses to the next line: With the current implementation, if you type in an address which is longer than the width of the screen, it stretches the person card (for all contacts), forcing the user to scroll to the right to see the rest of the address, the project status and deadline. In future updates, we plan to enable textWrap and set a maxWidth for the address label to enhance the UI and improve readability.
   
2. Add support for patronymics, like ‘s/o’ or ‘d/o’, in the name field: The current implementation only allows alphanumeric characters, spaces, and dashes, and so users have to work around this restriction by using “s o” or “son of”. In the future, we will adjust the regex to something like this [\\p{Alnum}]+(([ -][\\p{Alnum}]+)*|(([ -](s|d)/o\\s)[\\p{Alnum}]+))\\s* to allow special strings like “s/o” and “d/o”.
   
3. Make prefix for deadlines dl/: This is in conjunction with point 2. Our current implementation of deadline is implemented with d/DEADLINE. If we implement a regex to accept “d/o”, this would trigger an error since it would match “d/”. In the future, we will change the prefix to something like PREFIX_DEADLINE = new Prefix("dl/").
   
4. Allow users to clear current sorting scheme: Currently, users cannot ‘undo’ a sort command. In the future, we plan to add an undo and redo feature, which will complete this enhancement as well. Do refer to the proposed undo and redo feature.
   
5. Adjust sorting function to maintain order for identical names/deadlines: Currently, when multiple entries share the same name or deadline, sorting them may cause reordering if a different field (i.e project status) is changed afterward. The reason for this is due to a bug with the way SortedList is implemented. For details on this bug, and how we plan to enhance it in the future, refer to Appendix: Sorted List Bug.
   
6. Make add and edit commands accept blacklisted client status: The current implementation throws an error of invalid command format for the parameter cs/blacklisted. Users can work around this by using the blacklist command implemented. In the future, we plan to remove the restriction on blacklisted client status from both AddCommandParser and EditCommandParser.
   
7. Make rejection of blacklisted client status for add and edit command more specific: This is an alternative to point 6 above. The current error message thrown is "Invalid command format! which does not accurately explain to the user that the issue lies with the blacklisted parameter. We plan to make the error message mention that cs/blacklisted cannot be used for this command. It is important to note that this enhancement will be deemed redundant if point 6 is implemented, where cs/blacklisted is indeed accepted.
   
8. Reject email inputs without a period between alphanumeric characters for the domain portion: Currently, an input like e/john@example is accepted, however, this should not be the case as a valid domain format would require at least 1 period for the top level domain (ie.john@example.com). We plan to adjust the regex for the domain portion of the email from "(" + DOMAIN_PART_REGEX + "\\.)*" to "(" + DOMAIN_PART_REGEX + "\\.)+" to reject such an input.
   
9. Make INDEX 0 and negative INDEX error messages more specific: Currently, when 0 or negative numbers are passed for the INDEX parameter, the error message thrown is Invalid command format!. In the future, we will change this error message to The person index provided is invalid.

Appendix: Sorted List Bug

Initially reported here

Description of SortedList bug:

An issue in SortedList.sourceChanged() arises when an element in the source list is replaced using set(index, element). Normally, ObservableList creates a ListChangeEvent with a remove and an add event, but SortedList may misplace elements with a comparator result of 0(i.e if they’re being sorted by name and have the same name), adding the new element in the wrong position. This becomes problematic in tables(such as how our clients are displayed).

Note: This bug is an issue with all sort command combinations: sorting by name or deadline in either ascending or descending order can be used to reproduce the bug.

Steps to reproduce:

1. Add multiple people (at least 3) with the same name (i.e John) and make the phone numbers 1111 1111, 2222 2222, 3333 3333, …
2. Observe the initial order
3. Do a sort command (sort name ascending)
4. Start editing other fields of these John’s (i.e edit their project status)
5. After doing some of these edits, you will most likely see the list order change among Johns

In the future, we will firstly modify the program, such that it no longer uses SortedList.

1. In ModelManager, delete the sortedPersons variable
2. This will include modifying the getFilteredPersonList() method, to return filteredPersons, instead of sortedPersons.
3. Replace the sortByComparator method to use the FXCollections.sort() method. This is sample code that can be used (modification may be necessary)

@Override
public void sortByComparator(Comparator<Person> comparator) {
    currentComparator = comparator;
    int initialSize = addressBook.getPersonList().size();

    ObservableList<Person> sortedList = FXCollections.observableArrayList(addressBook.getPersonList());
    FXCollections.sort(sortedList, comparator);

    addressBook.setPersons(sortedList);
    assert addressBook.getPersonList().size() == initialSize;
}

Note: This will make the current implementation such that the list only sorts when a sort command is executed. For instance, if the client list becomes A, J, J, Z after a sort name ascending command, then a client B is added, the list will become A, J, J, Z, B.

If you wish for the list to automatically sort as clients are added / edited, you will need to modify the addPerson and setPerson command in ModelManager. Simply add a check to test if a sort is activated, and if so, after the modification of the list, perform a sort. The following code can be used as an example:

if (currentComparator != null && !isArchivedList) {
    sortByComparator(currentComparator);
}

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.

Adding a person

1. Adding a client while the client list is shown

   1. Prerequisites: List all clients using the list command.

   2. Test case: add n/Michael Jackson p/12345678 e/Michael@gmail.com a/Block 17 d/10-10-2024
      Expected: The client is added. Details of the added client is shown in the status message with
      in progress project status, pending payment status and active client status

Editing a person

1. Editing a client while the client list is shown

   1. Prerequisites: Ensure you have at least 2 clients in the list, and that the client in the first position of the list has the following parameters, NAME: Jack, PHONE_NUMBER: 999, EMAIL: Jack@gmail.com

   2. Test case: edit 2 n/Jack p/999 e/Jack@gmail.com
      Expected: The error message This person already exists in either the address book or the archived address book. is shown.

Finding a person

1. Finding a client while the client list is shown

   1. Prerequisites: Delete your data folder to start with the sample client list

   2. Test case: find n/b
      Expected: The list has a size of 2 and displays the clients with NAME Bernice Yu and Roy Balakrishnan

Deleting a person

1. Deleting a client while the client list is shown

   1. Prerequisites: List all clients using the list command. Multiple clients with the same name exist.

   2. Test case: delete id/1
      Expected: First client is deleted from the list. Details of the deleted client shown in the status message.

   3. Test case: delete id/0
      Expected: No client is deleted. Error details shown in the status message.

   4. Test case: delete n/John Doe
      Expected: Client with name John Doe is deleted. Details of the deleted client shown in the status message.
      If multiple John Does exist, list of all John Does is displayed.
      User prompted to delete by index in status message.

   5. Other incorrect delete commands to try: delete, delete p/x (incorrect prefixes), delete id/y, ... (where y is larger than the list size)
      Expected: Similar to previous.

Saving data

1. Dealing with missing or corrupted data files

   1. preferences.json
      1. Move preferences.json to another folder.
      2. Relaunch the app.

      Expected: Application launches with the default window size.

   2. config.json
      1. Move config.json to another folder.
      2. Relaunch the app.

      Expected: Application launches, config file is re-created with default configuration.

   3. addressbook.json
      1. Corrupted:
         1. Manually modify addressbook.json
         2. Relaunch the app

         Expected: Application fails to read from the file and loads without any data.

      2. Missing:
         1. Move data folder to another directory.
         2. Relaunch the app.

         Expected: Application loads with the sample data.