What is the PaperNet Chaincode (Smart Contract), papercontract.js?

papercontract.js is the chaincode (or smart contract) for the PaperNet written in Node.js language.

1. View papercontract.js source code:

(magnetocorp admin)$ cd ~/hyperledger-binaries/fabric-samples
(magnetocorp admin)$ cd commercial-paper/organization/magnetocorp/contract
(magnetocorp admin)$ more lib/papercontract.js

/* SPDX-License-Identifier: Apache-2.0
*/

'use strict';

// Fabric smart contract classes
const { Contract, Context } = require('fabric-contract-api');

// PaperNet specifc classes
const CommercialPaper = require('./paper.js');
const PaperList = require('./paperlist.js');

/** A custom context provides easy access to list of all commercial papers
 */
class CommercialPaperContext extends Context {
    constructor() {
        super();
        // All papers are held in a list of papers
        this.paperList = new PaperList(this);
    }
}

/** Define commercial paper smart contract by extending Fabric Contract class
 *
 */
class CommercialPaperContract extends Contract {
    constructor() {
        // Unique namespace when multiple contracts per chaincode file
        super('org.papernet.commercialpaper');
    }

    createContext() {
        return new CommercialPaperContext();
    }

    /** Instantiate to perform any setup of the ledger that might be required.
     * @param {Context} ctx the transaction context
     */
    async instantiate(ctx) {
        // No implementation required with this example
        // It could be where data migration is performed, if necessary
        console.log('Instantiate the contract');
    }

    /** Issue commercial paper
     *
     * @param {Context} ctx the transaction context
     * @param {String} issuer commercial paper issuer
     * @param {Integer} paperNumber paper number for this issuer
     * @param {String} issueDateTime paper issue date
     * @param {String} maturityDateTime paper maturity date
     * @param {Integer} faceValue face value of paper
    */
    async issue(ctx, issuer, paperNumber, issueDateTime, maturityDateTime, faceValue) {
        ...
        return paper.toBuffer();
    }

    /** Buy commercial paper
     *
     * @param {Context} ctx the transaction context
     * @param {String} issuer commercial paper issuer
     * @param {Integer} paperNumber paper number for this issuer
     * @param {String} currentOwner current owner of paper
     * @param {String} newOwner new owner of paper
     * @param {Integer} price price paid for this paper
     * @param {String} purchaseDateTime time paper was purchased (i.e. traded)
    */
    async buy(ctx, issuer, paperNumber, currentOwner, newOwner, price, purchaseDateTime) {
        ...
        return paper.toBuffer();
    }

    /** Redeem commercial paper
     *
     * @param {Context} ctx the transaction context
     * @param {String} issuer commercial paper issuer
     * @param {Integer} paperNumber paper number for this issuer
     * @param {String} redeemingOwner redeeming owner of paper
     * @param {String} redeemDateTime time paper was redeemed
    */
    async redeem(ctx, issuer, paperNumber, redeemingOwner, redeemDateTime) {
        ...
        return paper.toBuffer();
    }

}

module.exports = CommercialPaperContract;

As you can see, papercontract.js offers 3 functions: issue, buy and redeem for the PaperNet chaincode. Client applications can submit transactions correspondingly to issue, buy and redeem commercial paper on the ledger.

 

⇒ Install PaperNet Chaincode (Smart Contract)

⇐ Start CLI Container for MagnetoCorp Admin

⇑ commercial-paper Sample Network

⇑⇑ Hyperledger Tutorials