Cloud based Library Management Service (IT752 Internet and Web Technology Lab Project)

Project Statement

There are two types of users: student and faculty. They can browse books available. For students the maximum duration to hold a title is 30 days and for faculty it is 180 days. 5 and 8 are the upper limits of holding number of books for student and faculty respectively. Same title cannot be issued to a user. Holding a title more than the speculated duration will be charged ₹ 1/- per day. A mail will be sent as a warning two days before the due date of each title held.

Demo

View demo discussion.

Tech Stack

So far (project in progress)

The project is built using the MERN stack plus PostgreSQL and GraphQL. TypeScript instead of conventional JavaScript is used throught.

Front end

• React
• SASS

Back end

• Node
• Express
• GraphQL.js
• Mongo DB (Atlas - AWS)
• Mongoose
• PostgreSQL (AWS)
• AMQP (RabbitMQ)

Architecture

• The application has a loosely coupled frontend and backend architecture.
• The frontend is implemented in React 17 and SASS.
• The backend is implemented in Node.js and Express.js.
• The communication API is implemented in GraphQL.js which is configured in the backend.
• A polygot DBMS is used — stationary data handling is done by (NoSQL) MongoDB via Mongoose, while transaction data handling is done by (SQL) PostgreSQL.
• Both the DBMS are cloud hosted — MongoDB Atlas is used for MongoDB, while ElephantSQL is used for PostgreSQL.
• A single channel message queue is implemented via RabbitMQ to communicate between transaction resolvers of the API and the backend operations.

Note: I encountered some problems with my implementation of the message queue via RabbitMQ. The stringified JSON had some problems, and so, I've reversed the changes by directly resetting the main branch. I'll fix that and push the feature soon.

How to Run

Setup Databases

MongoDB

• Create a MongoDB Atlas account and create a cluster.
• Open collections in the cluster and visit the Command Line Tools tab.
• Scroll down to Data Import and Export Tools section and copy the import string. It should look like mongoimport --uri mongodb+srv://<USERNAME>:<PASSWORD>@cluster0.snhzr.mongodb.net/<DATABASE> --collection <COLLECTION> --type <FILETYPE> --file <FILENAME>
• Install MongoDB Tools and then open terminal.
• Follow for all 3 files in dummy database content: paste the string from above while filling the data in the <...> parts — for DATABASE use library, for COLLECTION use authors, books, users, one at a time, for FILETYPE use json, and finally for FILENAME provide path to each file relative to the terminal's PWD.

PostgreSQL

• Create an ElephantSQL account and create an instance.
• Install PostgreSQL (installs pgAdmin).
• Launch pgAdmin -> Right Click on Servers (left panel) -> Create Server.
• Fill in details (name, host, database, username, password) which you'll get once you create the ElephantSQL instance.
• After Server is added, expand it (left panel) -> expand Databases then scroll down to find your database and expand it -> expand Schemas -> expand Public.
• Right click on Tables -> Create Table for each table according to the schema: Joins are not being used here so it doesn't matter whether you use PRIMARY KEYs (PKs), but it serves as a constraint
  • "shelf" ("bookID" VARCHAR(16) PK, "quantity" numeric)
  • "notifications" ("userID" VARCHAR(16) PK, "bookID" VARCHAR(16) PK)
  • "awaiting" ("userID" VARCHAR(16) PK, "bookID" VARCHAR(16) PK, "type" VARCHAR(8), "createdAt" TIMESTAMP without Timezone)
  • "transactions" ("transID" VARCHAR(16) PK, "userID" VARCHAR(16), "bookID" VARCHAR(16), "borrowDate" TIMESTAMP without Timezone, "returnDate" TIMESTAMP without Timezone - can be NULL)
• For each table, Right click on table name after expanding Tables -> visit Tools (menu bar) -> click Import/Export -> Select file path followed by filename for each .csv file corresponding to each of the 4 tables, and import the dummy data.

Steps

• Install Node JS
• Clone Repository
• Setup Databases
• Install RabbitMQ
• Navigate to each of frontend and backend directories and run (in terminal) npm ci
• In frontend directory, run npm start
• In backend directory, edit the contents of .env file with your databases configuration information
• Start RabbitMQ service
• In backend directory, run npm run dev
• Launch web app from localhost:3000
• (optional) Launch GraphiQL app from localhost:8000/api

Note: Project doesn't adapt to varying screen sizes; designed and tested on a monitor having resolution 2560 × 1080 with 100% display scaling, checked to appear fine on 1920 × 1080 at 125% scaling. For other configurations, front-end design may look out of place.