Ark - Developer Guide

By: CS2103AUG2017 Team T16-B1 Since: Sept 2017 Licence: MIT

1. Introduction
- 1.1. What is Ark?
- 1.2. About this guide
2. Setting up
3. Design
4. Implementation
5. Documentation
6. Testing
7. Dev Ops
Appendix A: User Stories
Appendix B: Use Cases
Appendix C: Non Functional Requirements
Appendix D: Glossary
Appendix E: Product Survey

1. Introduction

1.1. What is Ark?

Ark is a Command Line Interface software that helps delivery and shipping vendors manage their parcels and deliveries. Ark allows these delivery companies to track the parcels that they have to deliver to their customers, and empowers delivery vendors with simple end-to-end management of these deliveries. Ark also provides route optimization features to help vendors optimize their deliveries based on time or distance.

1.2. About this guide

The purpose of this developer guide is to help incoming developers, project managers and executives understand the high-level details of the Ark software and help them develop code in coherence with our guidelines. Such details include the Ark architecture and system, its components and the interaction between these components.

This guide contains information pertaining to issues such as:

Setting up the development environment for Ark.
Understanding the high-level components of Ark.
Understanding the various features and their implementations in Ark.
Adding documentation to document the changes you have made.
Running tests for the code in Ark.
Details on how to manage the Ark project using Version Control and Continuous Integration.

2. Setting up

2.1. Prerequisites

JDK 1.8.0_60 or later

ℹ️
Having any Java 8 version is not enough.
This app will not work with earlier versions of Java 8.
IntelliJ IDE

ℹ️
IntelliJ by default has Gradle and JavaFx plugins installed.
Do not disable them. If you have disabled them, go to File > Settings > Plugins to re-enable them.

2.2. Setting up the project in your computer

Fork this repo, and clone the fork to your computer
Open IntelliJ (if you are not in the welcome screen, click File > Close Project to close the existing project dialog first)
Set up the correct JDK version for Gradle
1. Click Configure > Project Defaults > Project Structure
2. Click New… and find the directory of the JDK
Click Import Project
Locate the build.gradle file and select it. Click OK
Click Open as Project
Click OK to accept the default settings
Open a console and run the command gradlew processResources (Mac/Linux: ./gradlew processResources). It should finish with the BUILD SUCCESSFUL message.
This will generate all resources required by the application and tests.

2.3. Verifying the setup

Run the seedu.address.MainApp and try a few commands
Run the tests to ensure they all pass.

2.4. Configurations to do before writing code

2.4.1. Configuring the coding style

This project follows oss-generic coding standards. IntelliJ’s default style is mostly compliant with ours but it uses a different import order from ours. To rectify,

Go to File > Settings… (Windows/Linux), or IntelliJ IDEA > Preferences… (macOS)
Select Editor > Code Style > Java
Click on the Imports tab to set the order
- For Class count to use import with '*' and Names count to use static import with '*': Set to 999 to prevent IntelliJ from contracting the import statements
- For Import Layout: The order is import static all other imports, import java.*, import javax.*, import org.*, import com.*, import all other imports. Add a <blank line> between each import

Optionally, you can follow the UsingCheckstyle.adoc document to configure Intellij to check style-compliance as you write code.

2.4.2. Updating documentation to match your fork

After forking the repo, links in the documentation will still point to the CS2103AUG2017-T16-B1/main repo. If you plan to develop this as a separate product (i.e. instead of contributing to the CS2103AUG2017-T16-B1/main) , you should replace the URL in the variable repoURL in DeveloperGuide.adoc and UserGuide.adoc with the URL of your fork.

2.4.3. Setting up CI

Set up Travis to perform Continuous Integration (CI) for your fork. See UsingTravis.adoc to learn how to set it up.

Optionally, you can set up AppVeyor as a second CI (see UsingAppVeyor.adoc).

ℹ️	Having both Travis and AppVeyor ensures your App works on both Unix-based platforms and Windows-based platforms (Travis is Unix-based and AppVeyor is Windows-based)

2.4.4. Getting started with coding

When you are ready to start coding,

Before you start contributing to Ark, get some sense of the overall design by reading the Architecture section.

3. Design

3.1. Architecture

Figure 3.1.1 : Architecture Diagram

The Architecture Diagram given above explains the high-level design of the App. Given below is a quick overview of each component.

💡	The `.pptx` files used to create diagrams in this document can be found in the diagrams folder. To update a diagram, modify the diagram in the pptx file, select the objects of the diagram, and choose `Save as picture`.

Main has only one class called 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 method where necessary.

Commons represents a collection of classes used by multiple other components. Two of those classes play important roles at the architecture level.

EventsCenter : This class (written using Google’s Event Bus library) is used by components to communicate with other components using events (i.e. a form of Event Driven design)
LogsCenter : Used by many classes to write log messages to the App’s log file.

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.

Each of the four components

Defines its API in an interface with the same name as the Component.
Exposes its functionality using a {Component Name}Manager class.

For example, the Logic component (see the class diagram given below) defines it’s API in the Logic.java interface and exposes its functionality using the LogicManager.java class.

Figure 3.1.2 : Class Diagram of the Logic Component

Events-Driven nature of the design

The Sequence Diagram below shows how the components interact for the scenario where the user issues the command delete 1.

Figure 3.1.3a : Component interactions for delete 1 command (part 1)

ℹ️	Note how the `Model` simply raises a `AddressBookChangedEvent` when the address book data are changed, instead of asking the `Storage` to save the updates to the hard disk.

The diagram below shows how the EventsCenter reacts to that event, which eventually results in the updates being saved to the hard disk and the status bar of the UI being updated to reflect the 'Last Updated' time.

Figure 3.1.3b : Component interactions for delete 1 command (part 2)

ℹ️	Note how the event is propagated through the `EventsCenter` to the `Storage` and `UI` without `Model` having to be coupled to either of them. This is an example of how this Event Driven approach helps us reduce direct coupling between components.

The sections below give more details of each component.

3.2. UI component

Figure 3.2.1 : Structure of the UI Component

API : Ui.java

The UI consists of a MainWindow that is made up of parts e.g.CommandBox, ResultDisplay, ParcelListPanel, StatusBarFooter, BrowserPanel etc. All these, including the MainWindow, inherit from the abstract UiPart class.

The UI component uses 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.
Binds itself to some data in the Model so that the UI can auto-update when data in the Model change.
Responds to events raised from various parts of the App and updates the UI accordingly.

3.3. Logic component

Figure 3.3.1 : Structure of the Logic Component

Figure 3.3.2 : Structure of Commands in the Logic Component. This diagram shows finer details concerning XYZCommand and Command in Figure 3.3.1

API : Logic.java

Logic uses the AddressBookParser class to parse the user command.
This results in a Command object which is executed by the LogicManager.
The command execution can affect the Model (e.g. adding a parcel) and/or raise events.
The result of the command execution is encapsulated as a CommandResult object which is passed back to the Ui.

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

Figure 3.3.3 : Interactions Inside the Logic Component for the delete 1 Command

3.4. Model component

Figure 3.4.1 : Structure of the Model Component

API : Model.java

The Model,

stores a UserPref object that represents the user’s preferences.
stores the data from interactions with AddressBook.
exposes an unmodifiable ObservableList<ReadOnlyParcel> 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.
does not depend on any of the other three components.

3.5. Storage component

Figure 3.5.1 : Structure of the Storage Component

API : Storage.java

The Storage component,

can save UserPref objects in json format and read it back.
can save the Address Book data in xml format and read it back.

3.6. Common classes

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

4. Implementation

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

4.1. Undo/Redo mechanism

The undo/redo mechanism is facilitated by an UndoRedoStack, which resides inside LogicManager. It supports undoing and redoing of commands that modifies the state of address book (e.g. add, edit). Such commands will inherit from UndoableCommand.

UndoRedoStack only deals with UndoableCommands. Commands that cannot be undone will inherit from Command instead. The following diagram shows the inheritance diagram for commands:

Figure 4.1.1 : Inheritance diagram for commands

As you can see from the diagram, UndoableCommand adds an extra layer between the abstract Command class and concrete commands that can be undone, such as the DeleteCommand. Note that extra tasks need to be done when executing a command in an undoable way, such as saving the state of the address book before execution. UndoableCommand contains the high-level algorithm for those extra tasks while the child classes implements the details of how to execute the specific command. Note that this technique of putting the high-level algorithm in the parent class and lower-level steps of the algorithm in child classes is also known as the template pattern.

Commands that are not undoable are implemented this way:

public class ListCommand extends Command {
    @Override
    public CommandResult execute() {
        // ... list logic ...
    }
}

With the extra layer, the commands that are undoable are implemented this way:

public abstract class UndoableCommand extends Command {
    @Override
    public CommandResult execute() {
        // ... undo logic ...

        executeUndoableCommand();
    }
}

public class DeleteCommand extends UndoableCommand {
    @Override
    public CommandResult executeUndoableCommand() {
        // ... delete logic ...
    }
}

Suppose that the user has just launched the application. The UndoRedoStack will be empty at the beginning.

The user executes a new UndoableCommand, delete 5, to delete the 5th parcel in the address book. The current state of the address book is saved before the delete 5 command executes. The delete 5 command will then be pushed onto the undoStack (the current state is saved together with the command).

Figure 4.1.2 : State of the undoStack and redoStack after delete 5 is executed

As the user continues to use the program, more commands are added into the undoStack. For example, the user may execute add n/David … to add a new parcel.

Figure 4.1.2 : State of the undoStack and redoStack after add n/David is executed

ℹ️	If a command fails its execution, it will not be pushed to the `UndoRedoStack` at all.

The user now decides that adding the parcel was a mistake, and decides to undo that action using undo.

We will pop the most recent command out of the undoStack and push it back to the redoStack. We will restore the address book to the state before the add command executed.

Figure 4.1.3 : State of the undoStack and redoStack after undo is executed

ℹ️	If the `undoStack` is empty, then there are no other commands left to be undone, and an `Exception` will be thrown when popping the `undoStack`.

The following sequence diagram shows how the undo operation works:

Figure 4.1.4 : Sequence diagram of the undo operation

The redo does the exact opposite (pops from redoStack, push to undoStack, and restores the address book to the state after the command is executed).

ℹ️	If the `redoStack` is empty, then there are no other commands left to be redone, and an `Exception` will be thrown when popping the `redoStack`.

The user now decides to execute a new command, clear. As before, clear will be pushed into the undoStack. This time the redoStack is no longer empty. It will be purged as it no longer make sense to redo the add n/David command (this is the behavior that most modern desktop applications follow).

Figure 4.1.5 : State of the undoStack and redoStack after clear is executed

Commands that are not undoable are not added into the undoStack. For example, list, which inherits from Command rather than UndoableCommand, will not be added after execution:

Figure 4.1.6 : State of the undoStack and redoStack after list is executed

The following activity diagram summarize what happens inside the UndoRedoStack when a user executes a new command:

Figure 4.1.7 : The activity diagram describing what happens inside the UndoRedoStack when the user executes a new command

4.1.1. Design Considerations

Aspect: Implementation of UndoableCommand

Alternative 1 (current choice): Add a new abstract method executeUndoableCommand()
- Pros: We will not lose any undone/redone functionality as it is now part of the default behaviour. Classes that deal with Command do not have to know that executeUndoableCommand() exist.
- Cons: Hard for new developers to understand the template pattern.
Alternative 2: Just override execute()
- Pros: Does not involve the template pattern, easier for new developers to understand.
- Cons: Classes that inherit from UndoableCommand must remember to call super.execute(), or lose the ability to undo/redo.

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 parcel being deleted).
- Cons: We must ensure that the implementation of each individual command are correct.

Aspect: Type of commands that can be undone/redone
Alternative 1 (current choice): Only include commands that modifies the address book (add, clear, edit).
- Pros: We only revert changes that are hard to change back (the view can easily be re-modified as no data are lost).
- Cons: User might think that undo also applies when the list is modified (undoing filtering for example), only to realize that it does not do that, after executing undo.
Alternative 2: Include all commands.
- Pros: Might be more intuitive for the user.
- Cons: User have no way of skipping such commands if he or she just want to reset the state of the address book and not the view.
- Additional Info: See our discussion here.

Aspect: Data structure to support the undo/redo commands

Alternative 1 (current choice): Use separate stack for undo and redo
- Pros: Easy to understand for new Computer Science student undergraduates to understand, who are likely to be the new incoming developers of our project.
- Cons: Logic is duplicated twice. For example, when a new command is executed, we must remember to update both HistoryManager and UndoRedoStack.
Alternative 2: Use HistoryManager for undo/redo
- Pros: We do not need to maintain a separate stack, and just reuse what is already in the codebase.
- Cons: Requires dealing with commands that have already been undone: We must remember to skip these commands. Violates Single Responsibility Principle and Separation of Concerns as HistoryManager now needs to do two different things.

4.2. Logging

We are using java.util.logging package for logging. The LogsCenter class is used to manage the logging levels and logging destinations.

The logging level can be controlled using the logLevel setting in the configuration file (See Configuration)
The Logger for a class can be obtained using LogsCenter.getLogger(Class) which will log messages according to the specified logging level
Currently log messages are output through: Console and to a .log file.

Logging Levels

SEVERE : Critical problem detected which may possibly cause the termination of the application
WARNING : Can continue, but with caution
INFO : Information showing the noteworthy actions by the App
FINE : Details that is not usually noteworthy but may be useful in debugging e.g. print the actual list instead of just its size

4.3. Configuration

Certain properties of the application can be controlled (e.g App name, logging level) through the configuration file (default: config.json).

4.4. Google Maps Search Browser

The google maps search browser enhancement resides within the BrowserPanel. It takes in a ReadOnlyParcel 's postal code number substring of the parcel’s address and concatenates it to the back of Google Map’s search URL prefix to get a URL for the browser to load.

4.4.1. Design Considerations

Aspect: Implementation of Google Maps Search Browser

Alternative 1 (current choice): Change browser loadPage URL to Google Map search URL
- Pros: Its easy to implement new methods to load a new URLs if required to display a different URL.
- Cons: The map has no other functionality besides searching for the postal code.
Alternative 2 (future implementation choice): Implementing through Google Maps API
- Pros: Makes it easier for implementing additional features that utilizes the Maps API which would be required
  in future versions of the Ark application.
- Cons: More difficult to implement and integrate into a command line interface.

4.5. Delete Tag mechanism

The delete tag mechanism is facilitated by a deleteTag method within the ModelManager. It supports the deletion of tags from every single parcel in Ark.

We first retrieve the list of parcels in Ark and iterate through each parcel and recreate the parcel object using the original parcel. We then check if tag we want to remove is present in the new parcel’s list of tags. If the tag is present, we remove it, otherwise, we do nothing. We then update the old parcel in Ark with the new parcel with the updated list of tags.

4.5.1. Design Considerations

Aspect: Implementation of deleteTagCommand

Alternative 1 (current choice): Add method to delete tags in ModelManager
- Pros: It is easy to implement a method to remove every instance where the Tag appears, we only have to be able to correctly iterate through all the lists of tags.
- Cons: Might be computationally expensive for large number of parcels as Ark will need to iterate through every Tag to delete them.
Alternative 2: Maintain a list of tags and where the tags are located+
- Pros: Computationally quicker to just find the tag and remove the tag from every parcel in the list of tags
- Cons: More difficult to implement as we have to store an additional list of tags which is linked to each parcel and has to be updated whenever we edit other parcel details as well.

4.6. Backup Mechanism

The back up mechanism is facilitated by a backupAddressBook() method within the StorageManager. It supports the backing up of AddressBook data in Ark.

Figure 4.6.1 : Sequence diagram describing the operation of the storageManager when it is initialized

The backupAddressBook() method is called automatically when storageManager is initialised in MainApp#init(), a method that is called when Ark is launched. The method utilises the StorageManager#saveAddressBook() method and stores the backup in the same directory as the main AddressBook storage file. The backup file is saved and named with the name of the main AddressBook storage file appended with -backup.xml. i.e. If the main AddressBook storage file is named as addressbook.xml, the backup storage file will be saved as addressbook.xml-backup.xml.

4.6.1. Design Considerations

Aspect: Implementation of StorageManager#backupAddressBook

Alternative 1 (current choice): use the aveAddressBook() method to implement logic.
- Pros: It becomes easier to implement method rather than writing out a separate logic for backupAddressBook(). It makes updates easier since enhancements to saveAddressBook() will also enhance backupAddressBook().
- Cons: This implementation increases the coupling of backupAddressBook() and saveAddressBook() where changes in saveAddressBook() are likely to cause changes in backupAddressBook().
Alternative 2: Separate the implementation of backupAddressBook() from saveAddressBook()
- Pros: Reduced coupling of saveAddressBook() and backupAddressBook() and allows the backup file to be saved at a different location from the main save file. This prevents the backup file from being corrupted if the folder of the main save file becomes corrupted.
- Cons: More tedious to implement and maintain backupAddressBook() since enhancements to the saving feature has to be implemented in both saveAddressBook() and backupAddressBook()

Aspect: Trigger to execute backupAddressBook
* Alternative 1 (current choice): Automatically backup data on Ark on launch of the software.
Pros: This implementation ensures that the if the user corrupts the data of Ark during a session. The user will be able to revert to the start of the session, which is ensured to be a workable instance of the Ark software.
Cons: This does not give the most recent copy of the data of the Ark if many changes were made in a single session.
* Alternative 2: Backup data on Ark every few minutes
Pros: Provides a very recent copy of the data on Ark.
Cons: More tedious and difficult to implement. User may also be running another process at that point of time. It could cause a bottleneck if there is a lot of data to be saved, and multiple backup calls are queued one after the other.
* Alternative 3: Backup data after a fixed number of `UndoableCommand`s.
Pros: Provides a very recent copy of the data on Ark.
Cons: More tedious and difficult to implement. Difficult to determine the optimal amount of data to restore. If the corruption of the data is caused by a several of commands, it becomes difficult to ensure that the backup file provides a workable copy of the data of Ark.

4.7. Import Mechanism

To use this command, type import (FILE_NAME) into the CommandBox.

The Import mechanism allows users to import parcels from valid Ark storage files stored as .xml files into the current instance of Ark. This mecahnism is facilitated by a readAddressBook method within`XmlAddressBookStorage` to load the parcels stored in the xml file and an addAllParcels method defined in ModelManager to add the parcels in the storage file into the current instance of Ark.

Since the Import mechanism modifies the state of the data in Ark, it has to be undoable. Thus, it inherits from UndoableCommands interface rather than inheriting from the Command interface directly.

ℹ️

The file to be imported has to be stored in the ./data/import folder. i.e. calling import ark.xml will import the file ./data/import/ark.xml.
If the user enters a file name that is not alphanumeric or a file name that is not in a .xml format, the parcel will throw an Exception. This is to prevent a directory traversal attack on Ark. Read more about directory traversal attacks here

The following sequence diagram shows how the import operation works:

Figure 4.7.1 : Sequence diagram describing the operation of import when it is executed

ℹ️	The `ImportCommand` will only add parcels non-duplicate parcels. Duplicate parcels are ignored. If all the parcels to be imported into Ark are duplicates, then no parcels are imported and an Exception is thrown.

4.7.1. Design Considerations

Aspect: Implementation of ImportCommand

Alternative 1 (current choice): using readAddressBook() to implement the logic ImportCommand
- Pros: It becomes easier to implement method rather than writing out a separate logic to import files. It makes updates easier since enhancements to readAddressBook() will also enhance the import command such as more supported save file formats.
- Cons: This implementation increases the coupling of the readAddressBook() and ImportCommand such that changes in readAddressBook() is likely to cause a change in ImportCommand.
Alternative 2: Implement a parsing logic for ImportCommand.
- Pros: Reduced coupling of readAddressBook() and ImportCommand. This gives the developers more freedom on adding more file formats that can be imported.
- Cons: More tedious to implement and maintain ImportCommand since enhancements to the readAddressBook() feature has to be manually implemented in ImportCommand as well.

Aspect: Arguments to import files

Alternative 1 (current choice): Backup save files from only one location
- Pros: User will only stored his save files at one location, he will not store them at random locations and lose track of them. User only has to type the name of the file and does not need to type the full file path to locate the file. i.e. the user does not need to type ./data/import/Ark.xml.
- Cons: The user has restrictions on where he can import files from.
Alternative 2: User can load the files from any directory
- Pros: Allows user to import from his own archived folders anywhere in this computer.
- Cons: More tedious for the user to type in the full file path to locate the .xml file that he wants to import.

Aspect: Allowed file names that can be imported

Alternative 1 (current choice): File Names can only be alphanumeric and be in the .xml format.
- Pros: Ark is protected from directory traversal attacks.
- Cons: The user has restrictions on the file naming conventions he can use to name his import files
Alternative 2: No file name check
- Pros: Allows user to name his files following any conventions and be successfully imported into Ark.
- Cons: Makes Ark vulnerable to simple directory traversal attack where user can access files outside the data/import/ directory.

4.8. Tab autocomplete mechanism

Figure 4.8.1 : Sequence Diagram describing the operation of the Autocompleter when autocomplete is executed

The tab autocomplete mechanism is facilitated by the autocomplete method residing inside the Autocompleter. It supports the tab autocompletion for possible commands that that match the text in the CommandBox.

A new Autocompleter is initialized when the CommandBox is initialized as an attribute of the CommandBox. When the tab key is pressed by the user, CommandBox#processAutocomplete retrieves the text that is currently in the commandTextField and passes it into the Autocompleter#autocomplete as a string. If the string is empty, autocomplete raises a NewResultAvailableEvent to prompt the user to use the help command and returns an empty string.

If the string is not empty, the text in commandTextField will be converted into an array and stored in commandBoxTextArray. If there is only one word in the commandBoxTextArray, AutoCompleter#processOneWordAutocomplete will be called and the only word in commandBoxTextArray is passed in as a string commandBoxText. processOneWordAutocomplete will then pass commandBoxText into getClosestCommands. getClosestCommands then iterates through all the possible commands in commandList and compares them with commandBoxText using AutoComplete#isPossibleMatch . If isPossibleMatch returns true, the command is then stored inside the arrayList possibleResults. After iterating through commandList, getClosestCommands then returns possibleResults. If there is only one item inside possibleResults, processOneWordAutoComplete will return it to autocomplete which then returns it to processAutocomplete. If there is more than one item, a NewResultAvailableEvent is raised which prompts the user on the possible autocomplete commands available and returns the original value of commandBoxText.

After autocomplete returns a string to processAutocomplete, it then passes the string into CommandBox#replaceText to replace the text in commandFieldText with the string.

4.8.1. Design Considerations

Aspect: Implementation of autocomplete

Alternative 1 (current choice): Create a new Autocompleter class to implement autocomplete and its helper functions.
- Pros: Single Responsibility Principle (SRP) is maintained
- Cons: More tedious to implement and test since the feature is implemented in both Autocompleter and CommandBox. Also creates coupling between the Autocompleter and CommandBox.
Alternative 2: Implement autocomplete inside CommandBox
- Pros: Easier to test since CommandBoxTest has already been set up and implemented.
- Cons: CommandBox class now has multiple responsibilities, which violates SRP. +=== Tab autocomplete mechanism

4.9. TrackingNumber Field

Parcels have tracking numbers for delivery vendors to keep track of the parcels that they send out on a daily basis. This feature is important because a single person can have many parcels belonging to him. Tracking numbers are used to differentiate between the different parcels that are going to be delivered to the same person. Tracking numbers also serve as a better way of narrowing down and pinpointing parcels of interest since these numbers are more unique

ℹ️	Presently, the `Tracking Number` Field only has support for Registered Article tracking numbers belonging to SingPost. You can read more about their Registered Article tracking number here.

4.10. PostalCode Field

The PostalCode field is implemented as part of Address. This class stores the postal address of locations in Singapore. It only accepts values of s or S followed by 6 digits. The value stored in this class is used to store the postal code of the address. The value is used to query Google Maps when the select command is executed.

ℹ️

Presently, the PostalCode field still does a very relaxed validation and does not completely ensure that the postal code exists even though it might meet the criteria above. The team is working on producing a database of postal codes in Singapore by quering the Google Maps Distance Matrix API. In the meantime, it is assumed that users will enter the correct postal code.

4.11. Status field

Status is used to indicate the current stage of delivery that a parcel is at. It has 4 possible states:

PENDING - This means that the parcel has not been delivered and has not passed the date it is supposed to be delivered by.
DELIVERING - This means that the parcel is currently working being delivered to its destination address.
COMPLETED - This indicates that the parcel has been successfully delivered to its destination.
OVERDUE - This state indicates that the parcel has not been delivered and has passed its due date.

These states have different colours codes to allow users to differentiate the Status values more easily.

4.11.1. Design Considerations

Implementation of Status**
- Alternative 1 (current choice): Status is an enum class.
Pros: Status should only have fixed values. The user should also not be allowed to create new Status objects.
Cons: Less options for the user to alter the Status values
- Alternative 2: Allow the user to define any Status they wish.
Pros: Users have more versatility on naming conventions
Cons: It becomes more difficult to import data files since different users may use different terminologies to describe the same status of the parcel.

4.12. Delivery Date field

Delivery Date is used to indicate the delivery date that the parcel must be delivered by. The dates are only accepted if they are valid. The parcel list is maintained in sorted order by comparing their delivery dates, with the earliest on top.

4.13. Tags

`Tag`s are used to indicate how the parcel should be handled. Tags can contain one or more of the following `Tag`s:

FROZEN - This means the parcel should be refrigerated as its contents are temperature sensitive.
FLAMMABLE - This means that the parcels' contents are highly flammable and should be kept away from heat.
HEAVY - This indicates that the parcel is heavy and may require additional manpower to deliver.
FRAGILE - This state indicates that the parcels' contents can be broken easily and requires additional care when handling.

4.13.1. Design Considerations

Implementation of Tag**
- Alternative 1 (current choice): Tag is an enum class.
Pros: Tag`s should only have fixed values. The user should also not be allowed to create new `Tag objects.
Cons: Less options for the user to alter the Tag values
- Alternative 2: Allow the user to define any `Tag`s they wish.
Pros: Users have more versatility on naming conventions
Cons: It becomes difficult for delivery personnel to keep track of the tags since different personnel might use different tag names to refer to the same tag.

4.14. Maintain sorted mechanism

Figure 4.13.1 : Adding Alice to Ark, maintainSorted is actually called and returns void.

The list of parcels in Ark is maintained to be always in sorted order according to delivery dates, with the earliest being on the top. This is so that the user will be able to look at the more pertinent deliveries.

The list is sorted whenever a parcel is added, edited or if a redo command is made. This is because these commands are the ones that might possibly cause the new parcel to be placed in the wrong position.

To maintain the selected element despite sorting however, we require a way to track which parcel is selected. Static variables to track which card has been selected has been added to the Model class. The Model class now has the following methods: select, unselect, getPrevIndex, hasSelected and forceSelect. Whenever we select an item, we will use select to indicate that we have selected a parcel card and we will then re-select that particular card after we have sorted.

4.14.1. Design Considerations

Aspect: Implementation of maintainSorted
Alternative 1 (current choice): Constant sort the list of parcels whenever there is a change that potentially could disrupt the order of the list.
Pros: Intuitive and guarantees that list is sorted in the right order
Cons: Many commands have to be changed
Alternative 2: Insert the new / edited parcel to fit into the sorted list.
Pros: Use less computation as the list of parcels is already sorted.
Cons: More difficult to implement as we’ll need to implement our own sorting algorithm as opposed to just using the built in sorting methods.

5. Documentation

We use asciidoc for writing documentation.

ℹ️	We chose asciidoc over Markdown because asciidoc, although a bit more complex than Markdown, provides more flexibility in formatting.

5.1. Editing Documentation

See UsingGradle.adoc to learn how to render .adoc files locally to preview the end result of your edits. Alternatively, you can download the AsciiDoc plugin for IntelliJ, which allows you to preview the changes you have made to your .adoc files in real-time.

5.2. Publishing Documentation

See UsingTravis.adoc to learn how to deploy GitHub Pages using Travis.

5.3. Converting Documentation to PDF format

We use Google Chrome for converting documentation to PDF format, as Chrome’s PDF engine preserves hyperlinks used in webpages.

Here are the steps to convert the project documentation files to PDF format.

Follow the instructions in UsingGradle.adoc to convert the AsciiDoc files in the docs/ directory to HTML format.
Go to your generated HTML files in the build/docs folder, right click on them and select Open with → Google Chrome.
Within Chrome, click on the Print option in Chrome’s menu.
Set the destination to Save as PDF, then click Save to save a copy of the file in PDF format. For best results, use the settings indicated in the screenshot below.

Figure 5.3.1 : Saving documentation as PDF files in Chrome

6. Testing

6.1. Running Tests

There are three ways to run tests.

💡	The most reliable way to run tests is the 3rd one. The first two methods might fail some GUI tests due to platform/resolution-specific idiosyncrasies.

Method 1: Using IntelliJ JUnit test runner

To run all tests, right-click on the src/test/java folder and choose Run 'All Tests'
To run a subset of tests, you can right-click on a test package, test class, or a test and choose Run 'ABC'

Method 2: Using Gradle

Open a console and run the command gradlew clean allTests (Mac/Linux: ./gradlew clean allTests)

ℹ️	See UsingGradle.adoc for more info on how to run tests using Gradle.

Method 3: Using Gradle (headless)

Thanks to the TestFX library we use, our GUI tests can be run in the headless mode. In the headless mode, GUI tests do not show up on the screen. That means the developer can do other things on the Computer while the tests are running.

To run tests in headless mode, open a console and run the command gradlew clean headless allTests (Mac/Linux: ./gradlew clean headless allTests)

6.2. Types of tests

We have two types of tests:

GUI Tests - These are tests involving the GUI. They include,
1. System Tests that test the entire App by simulating user actions on the GUI. These are in the systemtests package.
2. Unit tests that test the individual components. These are in seedu.address.ui package.
Non-GUI Tests - These are tests not involving the GUI. They include,
1. Unit tests targeting the lowest level methods/classes.
  e.g. seedu.address.commons.StringUtilTest
2. Integration tests that are checking the integration of multiple code units (those code units are assumed to be working).
  e.g. seedu.address.storage.StorageManagerTest
3. Hybrids of unit and integration tests. These test are checking multiple code units as well as how the are connected together.
  e.g. seedu.address.logic.LogicManagerTest

6.3. Troubleshooting Testing

Problem: HelpWindowTest fails with a NullPointerException.

Reason: One of its dependencies, UserGuide.html in src/main/resources/docs is missing.
Solution: Execute Gradle task processResources.

7. Dev Ops

7.1. Build Automation

See UsingGradle.adoc to learn how to use Gradle for build automation.

7.2. Continuous Integration

We use Travis CI and AppVeyor to perform Continuous Integration on our projects. See UsingTravis.adoc and UsingAppVeyor.adoc for more details.

7.3. Making a Release

Here are the steps to create a new release.

Update the version number in MainApp.java.
Generate a JAR file using Gradle.
Tag the repo with the version number. e.g. v0.1
Create a new release using GitHub and upload the JAR file you created.

7.4. Managing Dependencies

A project often depends on third-party libraries. For example, Address Book depends on the Jackson library for XML parsing. Managing these dependencies can be automated using Gradle. For example, Gradle can download the dependencies automatically, which is better than these alternatives.
a. Include those libraries in the repo (this bloats the repo size)
b. Require developers to download those libraries manually (this creates extra work for developers)

Appendix A: User Stories

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

Priority	As a …	I want to …	So that I can…
`* * *`	new user	see usage instructions	refer to instructions when I forget how to use the App
`* * *`	onging user	have a backup of my addressbook data	restore my addressbook if the storage file becomes corrupted
`* * *`	user	add a new parcel
`* * *`	user	delete a parcel
`* * *`	user	find a parcel by name	locate details of parcels without having to go through the entire list
`* * *`	user	filter parcels by tags	view specific parcels that are assigned with specific tags
`* * *`	user	the browser to automatically search for the address of the selected parcel in Google Maps	so that I can automatically get information on how to get to an address automatically, on click.
`* * *`	delivery man who travels a lot	to know the shortest distance from one contact’s address to another
`* * *`	delivery man who travels a lot	set a reference location	find the shortest distance from my reference location to a parcel’s delivery location
`* * *`	delivery company	be able to keep track of my deliveries	deliver the packages on time
`* * *`	delivery company	be alerted for any deliveries to be done today	deliver the packages on time
`* * *`	delivery company	sort my deliveries by date	know which packages are more urgent to handle
`* * *`	delivery man	generate deliver route based on my list of deliveries	know schedule for the day
`* * *`	delivery company	add a list of deliveries in one shot using Comma Separated Values	conveniently parse information from other sources
`* * *`	delivery company	add deliveries individually
`* * *`	delivery company	check for deliveries close to deadline	better prepare for busy periods
`* * *`	delivery company	archive completed deliveries	refer to them in the future
`* *`	new user	to have an autocomplete for the commands	I do not need to remember the format of commands
`* *`	user	store the sender and receiver addresses	use these addresses as destinations/sources of my deliveries
`* *`	lazy user	send and receive parcel details to and from other companies	minimize the amount of data inputs
`* *`	forgetful user	be reminded of a parcel’s delivery date (if valid)	in case I forget the date
`* *`	user	share details with contacts with a specific tag	minimize chance of someone else seeing them by accident
`* *`	busy user	add and remove tasks	use addressbook as a task manager
`* *`	user with a changing schedule	edit created tasks	change the details of task
`* *`	user	assign contacts and locations to tasks	link my tasks with people and places
`* *`	user	assign an expiry date to tasks	tasks are deleted automatically
`* *`	lazy user	to be notified of the most optimal path of completing my deliveries based on travelling distance
`* *`	user	filter tasks according to location	be notified of deliveries I have at a specific location
`* *`	forgetful user	view daily deliveries	keep track of daily deliveries
`* *`	user	retrieve my exact location on my device	remember the current address and store my location
`*`	new user	input instructions into a chatbot interface	I do not need to remember the format of commands
`*`	user with many parcels in the address book	sort parcels by name	locate a parcel easily

{More to be added}

Appendix B: Use Cases

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

Use case: Delete parcel

MSS

User requests to list parcels
AddressBook shows a list of parcels and maximizes the ParcelListPanel in the MainWindow UI
User requests to delete a specific parcel in the list
AddressBook deletes the parcel

Use case ends

Extensions

2a. The list is empty

Use case ends
3a. The given index is invalid
- 3a1. AddressBook shows an error message.
  
  Use case resumes at step 2

Use case: Add parcel by prompt

MSS

User requests to add parcels without further details
AddressBook prompts user to input parcel identification number of parcel to add
User inputs identification number as requested
AddressBook prompts user to input name of recipient of parcel to add
User inputs name of recipient as requested
AddressBook prompts user to input phone number of recipient of parcel to add
User inputs phone number as requested
AddressBook prompts user to input email of recipient of parcel to add
User inputs email as requested
AddressBook prompts user to input delivery address of parcel to add
User inputs address as requested
AddressBook prompts user to input tags of parcel to add
User inputs tags as requested [optional]
AddressBook adds parcel

Use case ends

Extensions

3a. The user does not input a parcel identification number
- 3a1. AddressBook shows an error message
  
  Use case resumes at step 2

5a. The user does not input a name
- 5a1. AddressBook shows an error message
  
  Use case resumes at step 4
7a. The user does not input a valid phone number
- 7a1. AddressBook shows an error message
  
  Use case resumes at step 6

9a. The user does not input a valid email
- 9a1. AddressBook shows an error message
  
  Use case resumes at step 8
11a. The user does not input a valid address
- 11a1. AddressBook shows an error message
  
  Use case resumes at step 10
13a. The user does not input a tag
- 13a1. AddressBook shows that no tag has been entered
  
  Use case resumes at step 14

14. AddressBook shows error message if same parcel found

Use case ends

Use case: Upload image of Parcel from local files

MSS

User requests to list parcels
AddressBook shows a list of parcels and maximizes the ParcelListPanel in the MainWindow UI
User requests to upload image of a specific parcel in the list
AddressBook prompts for location of image
User inputs file path
AddressBook updates image

Use case ends

Extensions

2a. The list is empty

Use case ends.
6a. The file path given is invalid
- 6a1. AddressBook shows an error message
  
  Use case resumes at step 4
6b. The file type of file given is invalid
- 6b1. AddressBook shows an error message
  
  Use case resumes at step 4

Use case: Set user reference location

MSS

User requests to set reference location
AddressBook updates reference location

Use case ends

{More to be added}

Appendix C: Non Functional Requirements

Should work on any mainstream OS as long as it has Java 1.8.0_60 or higher installed.
Should be able to hold up to 1000 parcels without a noticeable sluggishness in performance for typical usage.
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.
Each Command should take at most 1 second to finish execution.
Should be able to handle any valid or invalid user input.
Should back up data inside the address book each time the user makes changes to the data.
Commands that do not require internet connection should still work when the user is not connected to the internet.
Should come with automated unit tests.
A new user should be able to use basic commands like add and delete without needing to refer to the help window after their first time using the application.
Should allow the user to upload images of any mainstream image format.
Hash String of the users personal contact information should only be made up of alphanumeric characters.
Should update the map automatically when the user changes their starting location.

{More to be added}

Appendix D: Glossary

Mainstream OS

Windows, Linux, Unix, OS-X

Appendix E: Product Survey

Product Name

Author: …

Pros:

…
…

Cons:

…
…

Files

DeveloperGuide.adoc

Latest commit

History

DeveloperGuide.adoc

File metadata and controls

Ark - Developer Guide

1. Introduction

1.1. What is Ark?

1.2. About this guide

2. Setting up

2.1. Prerequisites

2.2. Setting up the project in your computer

2.3. Verifying the setup

2.4. Configurations to do before writing code

2.4.1. Configuring the coding style

2.4.2. Updating documentation to match your fork

2.4.3. Setting up CI

2.4.4. Getting started with coding

3. Design

3.1. Architecture

Events-Driven nature of the design

3.2. UI component

3.3. Logic component

3.4. Model component

3.5. Storage component

3.6. Common classes

4. Implementation

4.1. Undo/Redo mechanism

4.1.1. Design Considerations

4.2. Logging

4.3. Configuration

4.4. Google Maps Search Browser

4.4.1. Design Considerations

4.5. Delete Tag mechanism

4.5.1. Design Considerations

4.6. Backup Mechanism

4.6.1. Design Considerations

4.7. Import Mechanism

4.7.1. Design Considerations

4.8. Tab autocomplete mechanism

4.8.1. Design Considerations

4.9. TrackingNumber Field

4.10. PostalCode Field

4.11. Status field

4.11.1. Design Considerations

4.12. Delivery Date field

4.13. Tags

4.13.1. Design Considerations

4.14. Maintain sorted mechanism

4.14.1. Design Considerations

5. Documentation

5.1. Editing Documentation

5.2. Publishing Documentation

5.3. Converting Documentation to PDF format

6. Testing

6.1. Running Tests

6.2. Types of tests

6.3. Troubleshooting Testing

7. Dev Ops

7.1. Build Automation

7.2. Continuous Integration

7.3. Making a Release

7.4. Managing Dependencies

Appendix A: User Stories

Appendix B: Use Cases

Use case: Delete parcel

Use case: Add parcel by prompt

Use case: Upload image of Parcel from local files

Use case: Set user reference location

Appendix C: Non Functional Requirements

Appendix D: Glossary

Appendix E: Product Survey