Parcel Bustle (Backend)

Parcel Bustle is a cutting-edge courier service app designed to streamline your courier and logistic needs. With this app, you can manage parcel deliveries and track shipments in real-time with no hassle.

This app is targeted for last-mile delivery services providers, specialising in transporting good from a distribution center to the end customer's doorstep. It allows workers to save parcel details into the system either using an Optical Character Recognition (OCR) tool, or by manual input. Customers will be contactable via WhatsApp with the click of a button, while the host can manage the parcels and workers' permission through the frontend interface.

• Frontend Repository (React Native with Redux, Expo)
• Backend Repository (Golang - Gin, GORM, MySQL)

Table of Contents

1. System Design
2. Functionalities
3. Technologies Used
4. Deployment
5. References

System Design

Entity Relationship Diagram

SQL Schema Diagram

Given the relationship between entities, a relational DB (in this case MySQL) would be more ideal to store the data. The schema is as shown below.

Do note that the password field will be hashed using bcrypt before it is stored in the DB.

System Architecture

An Object Relational Mapper (ORM) is used due to its

1. Flexibility: Isolates the code from the database queries, making it easier to amend the codes if the database technology were to be changed (e.g. from MySQL to PostgresSQL)
2. Simplicity: Performs data queries and manipulation using Golang rather than SQL language
3. Security: Prevents injection attack by using the database/sql argument placeholders to contruct the SQL statements

API Routes Overview

The detailed information of each API routes can be found below.

• Workers
• Parcels
• Customers
• Hosts
• Authentication

API Routes for Workers

Base URL for workers http://{domain-name}.com/api/workers.

Endpoint	Method	Description	Request Body	Response	Authentication Response
/	POST	Creates a new worker from request data sent as JSON	{  "username": string,  "email": string,  "password": string,  "first_name": string,  "last_name": string,  "contact": string,  "profile_image": string }	Status 200 - returns a success message Status 400 - returns an error message Status 500 - returns an error message
/	GET	Get a list of all workers, returned as JSON		Status 200 - returns data of all workers Status 500 - returns an error message
/:workerId	GET	Get a worker by their ID, returning worker data as JSON		Status 200 - returns data of the specific worker Status 404 - returns an error message indicating that the worker is not found Status 500 - returns an error message
/:workerId	PUT	Update data of a specific worker	{  "username": string,  "email": string,  "password": string,  "first_name": string,  "last_name": string,  "contact": string,  "profile_image": string }	Status 200 - returns data of the updated worker Status 400 - returns an error message Status 404 - returns an error message indicating that the worker is not found Status 500 - returns an error message	Status 401 - returns an error message requiring login Status 403 - returns an error message for invalid access token
/:workerId	DELETE	Delete a specific worker		Status 200 - returns data of the deleted worker Status 404 - returns an error message indicating that the worker is not found Status 500 - returns an error message	Status 401 - returns an error message requiring login Status 403 - returns an error message for invalid access token

API Routes for Parcels

Base URL for parcels http://{domain-name}.com/api/parcels.

Endpoint	Method	Description	Request Body	Response	Authentication Response
/	POST	Creates a new parcel from request data sent as JSON	{  "status": string,  "delivery_address": string,  "return_address": string,  "deliver_by": datetime,  "delivered_image": string,  "payment_type": string,  "payment_mode": boolean }	Status 200 - returns a success message Status 400 - returns an error message Status 500 - returns an error message	Status 401 - returns an error message requiring login Status 403 - returns an error message for invalid access token
/	GET	Get a list of all parcels, returned as JSON		Status 200 - returns data of all parcels Status 500 - returns an error message
/:parcelId	GET	Get a parcel by its ID, returning parcel data as JSON		Status 200 - returns data of the specific parcel Status 404 - returns an error message indicating that the parcel is not found Status 500 - returns an error message
/:parcelId	PUT	Update data of a specific parcel	{  "status": string,  "delivery_address": string,  "return_address": string,  "deliver_by": datetime,  "delivered_image": string,  "payment_type": string,  "payment_mode": boolean }	Status 200 - returns data of the updated parcel Status 400 - returns an error message Status 404 - returns an error message indicating that the parcel is not found Status 500 - returns an error message	Status 401 - returns an error message requiring login Status 403 - returns an error message for invalid access token
/:parcelId	DELETE	Delete a specific parcel		Status 200 - returns data of the deleted parcel Status 404 - returns an error message indicating that the parcel is not found Status 500 - returns an error message	Status 401 - returns an error message requiring login Status 403 - returns an error message for invalid access token
/worker/:workerId	GET	Get a parcel by worker ID, returning parcel data as JSON		Status 200 - returns data of the specific worker Status 404 - returns an error message indicating that the worker is not found Status 500 - returns an error message
/customer/:customerId	GET	Get a parcel by customer ID, returning parcel data as JSON		Status 200 - returns data of the specific customer Status 404 - returns an error message indicating that the customer is not found Status 500 - returns an error message

API Routes for Customers

Base URL for customers http://{domain-name}.com/api/customers.

Endpoint	Method	Description	Request Body	Response	Authentication Response
/	POST	Creates a new customer from request data sent as JSON	{  "first_name": string,  "last_name": string,  "contact": string }	Status 200 - returns a success message Status 400 - returns an error message Status 500 - returns an error message
/	GET	Get a list of all customers, returned as JSON		Status 200 - returns data of all customers Status 500 - returns an error message
/:customerId	GET	Get a customer by their ID, returning customer data as JSON		Status 200 - returns data of the specific customer Status 404 - returns an error message indicating that the customer is not found Status 500 - returns an error message
/:customerId	PUT	Update data of a specific customer	{  "first_name": string,  "last_name": string,  "contact": string }	Status 200 - returns data of the updated customer Status 400 - returns an error message Status 404 - returns an error message indicating that the customer is not found Status 500 - returns an error message	Status 401 - returns an error message requiring login Status 403 - returns an error message for invalid access token
/:customerId	DELETE	Delete a specific customer		Status 200 - returns data of the deleted customer Status 404 - returns an error message indicating that the customer is not found Status 500 - returns an error message	Status 401 - returns an error message requiring login Status 403 - returns an error message for invalid access token

API Routes for Hosts

Base URL for hosts http://{domain-name}.com/api/hosts.

Endpoint	Method	Description	Request Body	Response	Authentication Response
/	POST	Creates a new host from request data sent as JSON	{  "username": string,  "email": string,  "password": string,  "first_name": string,  "last_name": string, }	Status 200 - returns a success message Status 400 - returns an error message Status 500 - returns an error message
/	GET	Get a list of all hosts, returned as JSON		Status 200 - returns data of all hosts Status 500 - returns an error message
/:hostId	GET	Get a host by their ID, returning host data as JSON		Status 200 - returns data of the specific host Status 404 - returns an error message indicating that the host is not found Status 500 - returns an error message
/:hostId	PUT	Update data of a specific host	{  "username": string,  "email": string,  "password": string,  "first_name": string,  "last_name": string, }	Status 200 - returns data of the updated host Status 400 - returns an error message Status 404 - returns an error message indicating that the host is not found Status 500 - returns an error message	Status 401 - returns an error message requiring login Status 403 - returns an error message for invalid access token
/:hostId	DELETE	Delete a specific host		Status 200 - returns data of the deleted host Status 404 - returns an error message indicating that the host is not found Status 500 - returns an error message	Status 401 - returns an error message requiring login Status 403 - returns an error message for invalid access token

API Routes for Authentication

Base URL for hosts http://{domain-name}.com/api/auth.

Endpoint	Method	Description	Request Body	Response	Authentication Response
/login	POST	Validate credentials and generate authorisation cookies	{  "username": string,  "email": string,  "password": string }	Status 200 - returns a success message Status 400 - returns an error message Status 401 - returns an error message for wrong credentials Status 500 - returns an error message
/refresh	POST	Refresh expired access token with a refresh token		Status 200 - returns a new access token Status 500 - returns an error message	Status 401 - returns an error message requiring login Status 403 - returns an error message for invalid access token
/refresh	POST	Refresh expired access token with a refresh token		Status 204 - no response returned Status 500 - returns an error message	Status 401 - returns an error message requiring login Status 403 - returns an error message for invalid access token

Functionalities

Technologies Used

Frontend

• React Native
• Expo

Backend

• Gin - Server environment. GORM, CompileDaemon, godotenv, bcrypt, jwt, uuid
• MySQL/PostgresSQL - Database management

Deployment

Live Links

• React Native Frontend
• Gin Backend

Test Accounts

Account Type	Name	Email	Password
Worker	Mulan Hua	mulanhua@parcelbustle.com	mulanhua123@
Worker	Shang Li	shangli@parcelbustle.com	shangli123@
Worker	Chi Fu	chifu@parcelbustle.com	shangli123@
Host	Host 1	host1@parcelbustle.com	Not provided
Host	Host 2	host2@parcelbustle.com	Not provided
Host	Host 3	host3@parcelbustle.com	Not provided

References

1. Marcus, K. (2024 January 18). Go ORMs in 2024.