Developer Guide

This is a guide for developers looking to contribute to the codebase. There are explanations as to how the project is setup and how each command works.

You can click on the respective links below to read up on the relevant sections.

Table of Contents

• Introduction
• Setting up, getting started
• Design
  • Architecture
  • UI component
  • Logic component
  • Model component
  • Storage component
  • Common classes
• Implementation
  • AddXYZCommand
  • DeleteXYZCommand
  • Edit feature
  • FindXYZCommand
  • ListXYZCommand
  • [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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Introduction

Trackr is a desktop application catered towards small businesses to trackr their suppliers, customers and orders. It is for users who are quick typers to accomplish their tasks through the Command Line Interface (CLI) while reaping the benefits of a Graphical User Interface (GUI).

Acknowledgements

• This project is based on the AddressBook-Level3 project created by the SE-EDU initiative.
• If you would like to contribute code to the parent project (AddressBook-Level3), see se-education.org for more info.

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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_supplier 1.

Figure 2: Sequence Diagram (Deleting Person)

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.

Figure 3: Logic Class Diagram

The sections below give more details of each component.

UI component

The API of this component is specified in Ui.java

Figure 4: UI Class Diagram

The UI consists of a MainWindow that is made up of parts e.g.CommandBox, ResultDisplay, TabPanel, 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 Order, Task or Menu object residing in the Model.

Logic component

API : Logic.java

Here’s a (partial) class diagram of the Logic component:

Figure 5: Logic Class Diagram

How the Logic component works:

1. When Logic is called upon to execute a command, it uses the TrackrParser class to parse the user command.
2. This results in a Command object, which is actually an object of one of its subclasses, for example AddItemCommand, which is actually also an object of one of its subclasses, for example AddOrderCommand. This specific command will then be executed by the LogicManager.
3. The command can communicate with the Model when it is executed (e.g. to add an order).
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_order 1") API call.

Here are the other classes in Logic (omitted from the class diagram above) that are used for parsing a user command:

Figure 6: Sequence Diagram (Deleting Order)

How the parsing works:

• When called upon to parse a user command, the TrackrParser class creates an XYZCommandParser (XYZ is a placeholder for the specific command name e.g., AddOrderCommandParser) which uses the other classes shown above to parse the user command and create a XYZCommand object (e.g., AddOrderCommand) which the TrackrParser returns back as a Command object.
• All XYZCommandParser classes (e.g., AddOrderCommandParser, DeleteOrderCommandParser, …) inherit from the Parser interface so that they can be treated similarly where possible e.g, during testing.

Model component

API : Model.java

Figure 7: Model Class Diagram

The Model component,

• XYZ is a placeholder for the specific object (e.g., Supplier, Task), which are all Item objects.
• stores trackr data i.e., all XYZ objects (contained in respective UniqueXYZList object).
• stores currently ‘selected’ XYZ objects (e.g., results of search query) as a separate filtered list which is exposed to outsiders as an unmodifiable ObservableList<XYZ> that can be viewed (e.g. UI bound to this list so that the UI automatically updates when the data in the list changes).
• 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).

Here is the Item class that is what all model objects depend on.

Figure 8: Item Class Diagram

Each ItemList contains a UniqueItemList that stores a list of unique Items, which are defined by a model definiton (e.g., Supplier or Task from ModelEnum).

This is the class representation for the Supplier and Customer class.

Figure 9: Person Class Diagram

Here is how Supplier and Customer works:

• Supplier and Customer inherit off Person class, which depends on the Item class.
• Each Person contains their name, phone number, deadline, email and tags. (e.g., PersonAddress represents the address)
• The Supplier and Customer object have their corresponding List and UniqueList that stores their information.

This is the class representation for the Task class.

Figure 10: Task Class Diagram

Here is how Task works:

• Each Task contains their description, deadline and status (e.g., TaskName for task name).
• Each of the attributes inherits off the corresponding common classes (e.g., TaskName inherit off Name).
• The Task object have its List and UniqueList.

This is the class representation for the Menu class.

Figure 11: Menu Class Diagram

Here is how Menu works:

• Each Menu contains non-negative and non-zero number of MenuItem.
• Each MenuItem contains their description, price, cost and profit (e.g., ItemName for menu’s item name).
• The MenuItem’s ItemName attribute inherit off the corresponding common classes (e.g., ItemName inherit off Name).
• TheItemProfit is obtained using ItemPrice and ItemCost, meaning that ItemProfit depends on ItemPrice and ItemCost.
• The MenuItem object have its List called Menu and UniqueList.
• The MenuItem is an attribute of Order

Aspect: Choice to provide a menu package:

• Option 1 (our choice): Separating it into a separate menu package.
  • Advantage 1: Reduce the fuss of keying in the same name of the menu item repetitively when you add an order.
  • Advantage 2: Less repeated code
  • Disadvantage: More time required to implement.
• Option 2: Add item name as an attribute in the Order class.
  • Advantage: Convenient to implement.
  • Disadvantage: Higher chance of conflicts with another developer working on Order class.

This is the class representation for the Order class.

Figure 12: Order Class Diagram

Here is how Order works:

• Each OrderList contains non-negative and non-zero number of Order.
• Each Order contains a menu item(from a locally stored menu), customer, quantity, status and deadline (e.g., OrderStatus for order’s status).
• The menu item and customer each contains attributes as mentioned in their respective section above on how Menu and Customer works.
• The Order’s OrderDeadline and OrderStatus attribute inherit off the corresponding common classes (e.g., OrderDeadline inherit off Deadline).
• The Order object have its List called OrderList and UniqueList.

Storage component

API : Storage.java

Figure 13: Storage Class Diagram

The Storage component,

• can save both trackr data and user preference data in json format, and read them back into corresponding objects.
• inherits from both TrackrStorage 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 trackr.commons package.

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Implementation

This section describes the details on how the common commands are implemented.

The commands would be in the format <action>XYZCommand, where XYZ represents suppliers, customers, orders, menu items and tasks while action represents the action of the command.

AddXYZCommand

The add command creates and add object XYZ into XYZList and FilteredXYZList.It also saves into the internal XYZList, which stores all the XYZ objects, that matches the provided keywords.

The keywords that can be provided are the attributes as seen in the corresponding XYZ’s class diagram. For example, n/ would be followed by a task name for AddTaskCommand and order name for AddSupplierCommand.

The parser for the add command would extract out the arguments corresponding to each particular field.

The following activity diagram summarizes what happens when the user executes the add command.

Figure 14: Add Command Activity Diagram

Why is it implemented this way

The AddXYZCommand is an improved version of the original AB3 AddCommand by implementing into a abstract class -AddItemCommand. This reduces repeated lines of code and improves ease of implementation for future commands that require adding an item to a list.

DeleteXYZCommand

The delete command removes an XYZ from internal FilteredXYZList.

The command only accepts 1 argument without any prefixes. The argument corresponds to the index of XYZ in the FilteredXYZList that the user wishes to delete using a one-based index.

The parser for delete command extracts the index found in the arguments. If the argument is valid, then zero-based index is used to remove XYZ from the XYZList.

The following activity diagram summarizes what happens when the user executes the delete command.

Figure 15: Delete Command Activity Diagram

Why is it implemented this way

The DeleteXYZCommand is an improved version of the original AB3 DeleteCommand by implementing into a abstract class -DeleteItemCommand. This reduces repeated lines of code and improves ease of implementation for future commands that require removing an item from a list.

Edit feature

The edit command edits item XYZ from the internal XYZList.

This command requires user to key in the index of the item they wish to edit.

Edit supplier, edit order and edit task features are implemented using the same edit mechanism as described in this section.

The EditXYZCommandParser#parse() is used to parse the given command.

If the given command is valid, an EditXYZCommand will be returned and EditXYZCommand#execute() will then be called.

EditXYZCommand#execute() will first retrieve that latest filtered XYZ list from the model and check if the index given is valid.

If the given index is valid, item at given index will be retrieved. A copy of the item retrieved will be made and edited accordingly.

If changes to the original item is made and edited item is not the same as another existing item in the list, the edited item is saved to the filtered list and EditXYZCommand#execute() will return the CommandResult

Lastly, Changes made are saved to local data and success message will be shown.

Figure 16: Edit Command Activity Diagram

Why is it implemented this way

The EditXYZCommand is an improved version of the original AB3 EditCommand by implementing into a abstract class -EditItemCommand. This reduces repeated lines of code and improves ease of implementation for future commands that require editing an item in a list.

FindXYZCommand

The find command finds objects XYZ from the internal XYZList, which stores all the XYZ objects, that matches the provided keywords.

The keywords that can be provided are the same as those provided during the add and edit command. For example, n/ would represent a task name for FindTaskCommand and order name for FindSupplierCommand.

The parser for the find command would extract out the arguments corresponding to each particular field.

A XYZContainsKeywordPredicate is built upon these fields, which is used to test each XYZ object in the XYZList on whether they match the keywords provided.

The following activity diagram summarizes what happens when the user executes the find command.

Figure 17: Find Command Activity Diagram

Why is it implemented this way

The FindXYZCommand is an improved version of the original AB3 FindCommand by implementing into a abstract class -FindItemCommand. This reduces repeated lines of code and improves ease of implementation for future commands that require finding an item in a list. The abstract class ItemDescriptor stores the details of an item. It provides easier implementation for XYZContainsKeywordPredicate classes.

ListXYZCommand

The list command lists all the XYZ objects in the internal FilteredXYZList.

The command retrieves all the XYZ objects from the XYZList and places them in the FilteredXYZList.

The FilteredXYZList is then updated to have all XYZ objects, it will then to shown to the user.

The following activity diagram summarizes what happens when the user executes the list command.

Figure 18: List Command Activity Diagram

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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:

• Tech-savvy small businesses owners who:
  • lists their products online or on their own website
  • perform transactions manually without a Point-of-Sale (POS) system
  • Lack manpower/ time to track orders and contacts manually
  • Has a need to manage a significant number of contacts
• Prefer desktop apps over other types
• Can type fast
• Prefers typing to mouse interactions
• Is reasonably comfortable using CLI apps

Value proposition:

Our application:

• allows for consolidation of orders, contacts & tasks information which makes it easier to manage them. (no real-time automation)
• serves as a user-friendly alternative to free applications such as Microsoft Excel which may not be catered to their needs and requires tedious formatting. (no support for custom format of interface)
• enables faster contact management compared to a typical mouse/GUI driven app

User stories

High Priority (Must Have)

As a / an …​	I want to …​	So that I can…​
user	add new orders	have a consolidated place to keep track of my orders
user	view all my orders	track my progress in deadling with the orders
user	edit my orders	update my order status
user	find my orders by keywords	get a specific order without manually searching for it
user	delete my orders	remove unwanted old orders
user	add new customers (suppliers or customers)	easily find them from a consolidated location
user	find contacts by keywords	get the relevant contact information from a specific contact
user	edit my contacts	update past contacts with current information
user	delete my contacts	remove contacts not used anymore
user	add new tasks	keep track of business tasks from the same application
user	find tasks by keywords	get all relevant tasks that are related to plan my schedule
user	edit my tasks	update my progress on the task
user	delete my tasks	remove old completed tasks
new user	have an instruction guide	understand how to use the application

Medium Priority (Nice to Have)

As a / an …​	I want to …​	So that I can…​
business owner	add my menu items	add orders based on my menu items
business owner	edit my menu items	update my price and cost based on current rates
business owner	delete menu items	remove unpopular items that are not sold anymore
user	have my orders sorted	view my upcoming orders that are not done yet
user	have my tasks sorted	view the most pressing tasks at first glance
new user	be able to import past data	use the application easily when transferring data
user	be able to export data	keep track of past orders without lagging the application

Use cases

(For all use cases below, the System is the Trackr and the Actor is the Small Business Owner)

Use case: UC01 - Add a new supplier

MSS

1. Actor requests to add a new supplier.
2. Actor enters a command to add a supplier with the required information.
3. Trackr saves the new supplier to the system.

4. Trackr shows the new supplier added to the list.

   Use case ends.

Extensions

• 2a. The Actor does not enter all required information.

  • 2a1. Trackr shows an error message.

    Use case resumes at step 1.

• 2b. The Actor adds a supplier that already exists in the list.

  • 2b1. Trackr shows an error message.

    Use case resumes at step 1.

Use case: UC11 - Add a new customer

(Similar to UC01)

Use case: UC21 - Add a new task

(Similar to UC01)

Use case: UC31 - Add a new order

(Similar to UC01)

Use case: UC41 - Add a new menu item

(Similar to UC01)

Use case: UC02 - Delete a contact

MSS

1. Actor requests to list contacts.
2. Trackr shows a list of contacts.
3. Actor requests to delete a specific contact from the list.

4. Trackr deletes the contact.

   Use case ends.

Extensions

• 2a. The list is empty.

  Use case ends.

• 3a. The given index is invalid.

  • 3a1. Trackr shows an error message.

    Use case resumes at step 3.

Use case: UC22 - Delete a task

(Similar to UC01)

Use case: UC32 - Delete an order

(Similar to UC01)

Use case: UC42 - Delete a menu item

(Similar to UC01)

Use case: UC03 - Edit a contact

MSS

1. Actor requests to list contacts.
2. Trackr shows a list of contacts.
3. Actor enters an edit contact command for a specific contact and the updated information.

4. Trackr updates the contact details with the new information.

   Use case ends.

Extensions

• 2a. The list is empty.

  Use case ends.

• 3a. The Actor enters an invalid index.

  • 3a1. Trackr displays an error message.

    Use case resumes at step 3.

• 3b. The Actor enters invalid information.

  • 3b1. Trackr displays an error message.

    Use case resumes at step 3.

Use case: UC23 - Edit a task

(Similar to UC01)

Use case: UC33 - Edit an order

(Similar to UC01)

Use case: UC43 - Edit a menu item

(Similar to UC01)

Use case: UC04 - Finding a supplier

MSS

1. Actor requests to find a supplier.
2. Actor enters the command with the desired search criteria.
3. Trackr searches for suppliers that match the given criteria.

4. Trackr displays a list of suppliers that match the criteria.

   Use case ends.

Extensions

• 2a. The Actor does not enter any search criteria.

  • 2a1. Trackr displays an error message.

  • Use case resumes at step 2.

• 4a. No supplier matches the given search criteria.

  Use case ends.

Use case: UC14 - Find a customer

(Similar to UC01)

Use case: UC24 - Find a task

(Similar to UC01)

Use case: UC34 - Find an order

(Similar to UC01)

Use case: UC44 - Find a menu item

(Similar to UC01)

Use case: UC50 - Switch to another tab

MSS

1. Actor requests to switch to another tab.
2. Actor interacts with the tab menu.

3. Trackr switches to the target tab.

   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 200 supplier and customer contacts without a noticeable sluggishness in performance for typical usage.
3. Should be able to hold up to 1000 order details without a noticeable sluggishness in performance for typical usage.
4. Should be able to hold up to 200 tasks without a noticeable sluggishness in performance for typical usage.
5. 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.
6. Should store data locally only.

Glossary

• Mainstream OS: Windows, Linux, Unix, OS-X
• CLI: Command-Line Interface
• GUI: Graphical User Interface
• Supplier: Supplier refers to someone whom the user seasonally or frequently orders goods from
• Customer: Customer refers to someone whom the user receives an order from
• Order: Order refers to the customers’ orders the user accepts
• Task: Task refers to any to-dos the user may have, it need not be related to suppliers or orders (For instance, it can be about tidying inventory)
• Menu Item: Menu Item refers to any inventory/ stock that the user is selling to customers.
• Tag: Tags are associated with suppliers, users can tag the supplier with any keyword they want, number of tags are not restricted
• Status: Statuses are associated with tasks and orders, one entry of task/order can only have one status and the type of status that can be added is restricted

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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

3. Resize the window to an optimum size. Move the window to a different location. Close the window.

4. Re-launch the app by double-clicking the jar file.
   Expected: The most recent window size and location is retained.

5. { more test cases …​ }

Deleting a person

1. Deleting a person while all persons are being shown

2. Prerequisites: List all persons using the list command. Multiple persons in the list.

3. 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.

4. Test case: delete 0
   Expected: No person is deleted. Error details shown in the status message. Status bar remains the same.

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

6. { more test cases …​ }

Saving data

1. Dealing with missing/corrupted data files

2. {explain how to simulate a missing/corrupted file, and the expected behavior}

3. { more test cases …​ }