dapps.md

Creating a Decentralized Library DApp

setting up DApp

1. paste your contract address to variable libraryContractAddress on line 5 in utils.js.

-> insert this statements inside mounted() method in index.vue

    // init contract object
    await setLibraryContract();
    // fetch all books
    const books = await fetchAllBooks();
    this.posts = books;

2. set contract Object inside 'setLibraryContract()' method in [utils.js]

bookRentContract = await window.tronWeb.contract().at(libraryContractAddress);

3. postBook - copy below code inside postAd in bookForm.vue

// convert price from TRX to SUN
postBookInfo(this.title,this.description,tronWeb.toSun(this.price));

-> copy below code inside postBookInfo in utils.js

  const result = await bookRentContract.addBook(name,description,price).send({
    feeLimit:100_000_000,
    callValue:0,
    shouldPollResponse:true
  });

4. borrowBook - copy below code inside book() in detailsModal.vue

      // get Start date
      const startDay = this.getDayOfYear(this.startDate)
      // get End date
      const endDay = this.getDayOfYear(this.endDate)
      // price calculation
      const totalPrice =tronWeb.toSun(this.bookData.price) * (endDay - startDay)
      // call borrowBook function of contract 
      borrowBook(this.bookData.id, startDay, endDay, totalPrice)

-> copy below code inside borrowBook in utils.js

  const result = await bookRentContract.borrowBook(spaceId,checkInDate,checkOutDate).send({
    feeLimit:100_000_000,
    callValue:totalPrice,
    shouldPollResponse:true
  });

5. fetch all properties

-> insert inside fetchAllBooks() method in utils.js

  const bookId  = await bookRentContract.bookId().call();
  //iterate from 0 till bookId
  for (let i = 0; i < bookId; i++){
    const book = await bookRentContract.books(i).call()
    if(book.name!="") // filter the deleted books
    {
      books.push(
        {id: i,name: book.name,description: book.description,price: tronWeb.fromSun(book.price)}
      )
    }
    
  }
  return books

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