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: Instructions for manual testing
  • Launch and shutdown
  • Deleting a person
  • Saving data

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Acknowledgements

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

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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 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)

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.

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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.

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.

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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:

• 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: Our address book 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) - *

Priority	As a …​	I want to …​	So that I can…​
* * *	software developer	add clients	update my client list
* * *	software developer	remove clients	ensure my client list is not cluttered
* * *	software developer	view my clients and their details	access important client information
* * *	software developer	update my clients’ details	ensure my client list details are updated
* * *	software developer	view a client’s payment status	track who has paid and who still needs to make a payment
* * *	software developer	view a client’s project status	monitor the progress of each client’s project
* * *	software developer	view a client’s status	easily identify active clients
* *	software developer	filter my clients based on sections	easily find specific groups of clients
* *	software developer	sort clients by category	keep my client list organised
* *	software developer	set deadlines	ensure projects are completed before deadlines
* *	software developer	blacklist a client	avoid working with certain clients in future
* *	software developer	view clients on the blacklist	view all the clients I intend to avoid
* *	software developer	whitelist a blacklisted client	consider working with said client again
* *	software developer	view clients on the whitelist	view all clients that are not on the blacklist
* *	software developer	archive a client	store information of old clients without cluttering my client list
* *	software developer	unarchive a client	bring the information of archived clients back to the client list
* *	software developer	see reminders for the next earliest deadline	focus on the most urgent task first
*	software developer	keep notes for each client	take note of important details from meetings
*	software developer	undo previous commands	easily undo errors

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 at 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 at 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 at 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 at 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 given index is invalid.

  • 3a1. Clientele+ shows an error message.

    Use case resumes at step 2.

• 3b. The given details are invalid.

  • 3b1. Clientele+ shows an error message.

  Use case resumes at 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 at 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
• Private contact detail: A contact detail that is not meant to be shared with others
• Versioned AddressBook: An extension to the AddressBook class that allows undoing/redoing actions.

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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.

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.