Library

Requirements

• Node >= v12

Setup and test

# Install Dependencies
npm install

# Compile contracts
./node_modules/.bin/truffle compile

# Run local development RPC instance
./node_modules/.bin/ganache-cli

# Run tests
./node_modules/.bin/truffle test

Key terms

Administrator

Administrator is the person which can add new books in library

Book

Book consist of name, id and copies which is available in library of a given book.

Borrower

Borrower is a user which can take a book from library. He can only take a 1 copy of book per book.

BookLedger

BookLedger contain one - one mapping of ids with books.

Functions description

addBook(string memory _name, uint256 _copies)

• Only Adminstrator can call this function.
• It is used to add books in library.
• It also autogenerate an id and assign it to book.

Parameter description

• _name: name of book. Name of book is also unique. So there will be no 2 books having same name
• _copies: total number of copies of a book included in library

addBookCopies(uint256 _bookId, uint256 _copies)

• Only Adminstrator can call this function.
• It is used to add more copies of an existing book.

Parameter description

• _bookId: Id of book
• _copies: total number of copies of the book to add.

borrowBook(uint256 _id)

• It is a public function.
• It can only borrow a book which is available in the library
• User can only borrow 1 copy of book with given Id.
• Borrowing of book reduce the available copies of book by 1
• User cannot borrow books more than available copies of book with given id.

Parameter description

• id: id of a book present in library

returnBook(uint256 _id)

• It is a public function.
• User can only return a book if it is borrowed by given user.
• Returning of book will increase available copies by 1.

Parameter description

• id: id of a book present in library

getAllAvailableBooks()

• It is a public function.
• Return an array of bookIds which given user can borrow ie.. only books which are not borrowed by user and books whose copies are available in the library

getOwnerHistoryOfBook(uint256 _id)

• It is a public function.
• Return an array of addresses of user who borrowed the book untill present

Parameter description

• id: id of a book present in library

getBookDetail(uint256 _id)

• It is a public function.
• returns an name of book and available copies of given book

Parameter description

• id: id of a book present in library