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
• 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: NUS School of Computing Students

• He is a student in SOC
• He likes things to be fast and efficient
• Need to find connections
• Often needs to find students taking the same module for group work
• Often need to contact groupmates
• Loves using telegram for communication

Value proposition: DevBooks provides fast digital access to students in NUS SOC, making it easier to contact any student using their preferred mode of communication. Allow students to find project mates from the same project group easily and view the development profile of their contact.

User stories

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

Priority	As a …​	I want to …​	So that I can…​
* * *	beginner user	add a contact	i can retrieve it when I want
* * *	beginner user	add a phone number to a contact	I can easily message or call them when I need it
* * *	beginner user	tag my contacts	I can easily group my contacts
* * *	beginner user	list out all the contacts within my contact book	I can get an overview of everyone I’ve added so far
* * *	beginner user	delete a contact	I can declutter my contacts list if necessary
* * *	beginner user	look for list of available commands that I can use	I can know what commands I can use without memorizing
* *	beginner user	add a telegram handle to a contact	I can easily access my contact’s telegram when i need it
* *	beginner user	update a contact	I can update the details of my contacts when they change
* *	student	search for a contact by name	i can quickly find their contact details
* *	intermediate user	add all contact information all just with one line	I don’t need to do so manually using mutiple updates
* *	beginner user	delete a tag	I can remove outdated tags
* *	student	quickly scroll through using arrow keys in an alphabetical list	i find someone without typing.
* *	impatient user	load my contacts within 2 seconds	I do not need to wait too long to access my contacts
* *	beginner user	see the recently accessed contacts	I can know who I recently contacted
* *	beginner user	add an email address to a contact	I can easily email them when I need it
* *	beginner user	set a preferred mode of communication to a contact	I can reach them at their preferred platform when
* *	beginner user	add a contact to my favourites list	I can easily access them
* *	beginner user	see my favourites list	I can contact a favourite friend
* *	student	be able to group contacts by teams	i can access all members in one place.
* *	advanced user	be able to add multiple tags to a contact	i can find my groups quickly.
* *	intermediate user	access the github page of a contact	I can easily view their user activity and repos
* *	beginner user	filter my contacts by tags and name	I can find my contact(s) easier
* *	beginner user	get more details with each commands and flags	I am able to learn how to properly use each command/flag
* *	student	back up my contacts to a CSV	i dont lose my contacts if the device fails.
* *	student	import a list of contacts from a CSV or file	I can quickly add contacts to another device.
* *	advanced user	create customizable shortcuts	I can increase the speed of using the application
* *	advanced user	view a list of my shortcuts	I can see an overview of my customizations
* *	advanced user	create my own shortcuts	I can quickly type out long commands instantly
* *	intermediate user	access my command history through arrow keys	I can execute repeated operations quickly
* *	intermediate user	press “Tab” to auto-complete the command that I am typing out	I can quickly finish the command that I am typing.
* *	intermediate user	see hint text of what command would be autocompleted if I press “tab”	I have visual feedback before I autocomplete a command
* *	intermediate user	revert the last command	I can undo any mistakes
* *	beginner user	be able to rename my tags	I mass edit contacts with the same tag
* *	beginner user	add the github handle to a contact	I can easily access their github page in the future
* *	beginner user	delete all contacts associated with a tag	I can remove irrelevant contacts from my list
*	beginner user	go through a tutorial of the app	I can familiarize myself on how to use the app.
*	beginner user	read the documentation	I can get started on using the app
*	beginner user	import existing contacts from a .vcf file	I do not need to re-type all of my existing contacts
*	student	launch my telegram chat with the contact person through the app	I can start chatting with my contacts on telegram quickly
*	student	launch my email app quickly through the app	I can start writing email to my contacts quickly
*	student	delete contacts by date time query	my address book is clean.
*	advanced user	use DevBooks inside of my command console	I don’t need to open the application to perform an operation
*	aesthetic-minded individual	customize the theme of the application	it’s more personal to me

{More to be added}

Use cases

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

Use case: UC01 - Add Contact

MSS

1. Devbooks prompts for command
2. User input add command with required contact information
3. Devbooks saves contact and show success message

4. Devbooks shows the updated contact list

   Use case ends.

Extensions

• 2a. User input add command with invalid contact information

  • 2a1. Devbooks shows an error message

  • 2a2. User input new add command with contact information

    Steps 2a1-2a2 are repeated until the add command and contact information entered are correct.

    Use case resumes from step 3.

• 2b. Duplicated contact information found

  • 2b1. Devbooks shows an error message

  • 2b2. User input new add command with contact information

    Steps 2b1-2b2 are repeated until the new contact information does not duplicate with existing contacts.

    Use case resumes from step 3.

Use case: UC02 - Edit Contact

MSS

1. User edits contact in list
2. Devbook detects correct data in the entered data

3. Devbook updates the contact and displays the newly updated contact

   Use case ends.

Extensions

• 1a. Devbook detects an error in the entered data.

  • 1a1. Devbook prompts the user for the correct data.

  • 1a2. Beginner user enters new data.

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

    Use case resumes from step 2.

Use case: UC05 - Delete Contact

MSS

1. User inputs delete command with desired information to delete
2. Devbooks shows a confirmation prompt
3. User confirms intent to delete
4. Devbooks deletes the contact Use case ends.

Extensions

• 1a. Devbooks does not find a corresponding user to delete

  • 1a1. Devbooks shows an error message

    Use case ends.

• 3a. User inputs an invalid confirmation prompt

  • 3a1. Devbooks shows an error message

  • 3a2. Devbooks re-prompts for confirmation

    Steps 3a1-3a2 are repeated until the data entered are correct.

    Use case resumes from step 4.

Use case: UC09 – Find Contact by Name

MSS

1. User inputs a find command with keyword(s) to search
2. Devbooks validates the input and searches for matching contacts

3. Devbooks displays the matching contacts

   Use case ends.

Extensions

• 2a. User inputs an invalid search format

  • 2a1. Devbooks shows an error message
  • 2a2. Devbooks prompts for keywords
  • 2a3. User inputs find command with keyword(s) to search

  Steps 2a1–2a3 are repeated until valid input is provided.

  Use case resumes from step 3.

Use case: UC06 – Show list of commands

MSS

1. User inputs a help command to look up all commands available
2. Devbook lists out all the commands with its uses
3. Devbook prompts the user to select an available command for more details
4. User chooses specific help commands to look up details of one specific command.

5. Devbooks shows the specific instructions and guide on how to use that command

   Use case ends.

Extensions

• 3a. User did not select any commands to view command details

  Use case ends.

• 4a. User inputs a commands that does not exist in list of commands

  • 4a1. Devbooks shows an error message
  • 4a2. Devbooks prompts user to select available command
  • 4a3. User selects a command from list of available command

  Steps 4a1–4a3 are repeated until available command is selected.

  Use case resumes from step 5.

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. Should only be used by a single user (i.e. not a multi-user product).
5. Should store data locally and in a human editable text file.
6. Should not use a DBMS to store data.
7. Should work without requiring an installer.
8. Should not depend on a specific remote server.
9. Should be packaged into a single JAR file.
10. Should be able to load within 5 seconds. {More to be added}

Glossary

• CLI (command line interface): A text-based interface where users type commands to interact with the system.
• Development profile: A user’s GitHub profile used to store, manage, and showcase software development projects.
• Digital access: The ability to access DevBooks and retrieve information without needing any internet connection
• Flag/ Parameter: A prefix in a command (e.g. n/, p/, t/) used to specify values for different fields.
• Mainstream OS: Windows, Linux, Unix, MacOS
• NUS SOC: National University of Singapore, School of Computing
• Preferred Mode of communication: Telegram, Email or Phone
• Private contact detail: A contact detail that is not meant to be shared with others
• Project mates/ Project group: A project group is a team of students from the same module who work together on an assigned project. A project mate is a member of that group.
• Tag: A Label assigned to contacts for easy grouping and searching

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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 …​ }

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 …​ }