fabcar.js

/*
# Copyright IBM Corp. All Rights Reserved.
#
# SPDX-License-Identifier: Apache-2.0
*/

'use strict';
const shim = require('fabric-shim');
const util = require('util');

let Chaincode = class {

	// The Init method is called when the Smart Contract 'fabcar' is instantiated by the blockchain network
	// Best practice is to have any Ledger initialization in separate function -- see initLedger()
	async Init(stub) {
		console.info('=========== Instantiated fabcar chaincode ===========');
		return shim.success();
	}

	// The Invoke method is called as a result of an application request to run the Smart Contract
	// 'fabcar'. The calling application program has also specified the particular smart contract
	// function to be called, with arguments
	async Invoke(stub) {
		let ret = stub.getFunctionAndParameters();
		console.info(ret);

		let method = this[ret.fcn];
		if (!method) {
			console.error('no function of name:' + ret.fcn + ' found');
			throw new Error('Received unknown function ' + ret.fcn + ' invocation');
		}
		try {
			let payload = await method(stub, ret.params);
			return shim.success(payload);
		} catch (err) {
			console.log(err);
			return shim.error(err);
		}
	}

	async queryCar(stub, args) {
		if (args.length != 1) {
			throw new Error('Incorrect number of arguments. Expecting CarNumber ex: CAR01');
		}
		let carNumber = args[0];

		let carAsBytes = await stub.getState(carNumber); //get the car from chaincode state
		if (!carAsBytes || carAsBytes.toString().length <= 0) {
			throw new Error(carNumber + ' does not exist: ');
		}
		console.log(carAsBytes.toString());
		return carAsBytes;
	}

	async initLedger(stub, args) {
		console.info('============= START : Initialize Ledger ===========');
		let cars = [];
		cars.push({
			make: 'Toyota',
			model: 'Prius',
			color: 'blue',
			owner: 'Tomoko'
		});
		cars.push({
			make: 'Ford',
			model: 'Mustang',
			color: 'red',
			owner: 'Brad'
		});
		cars.push({
			make: 'Hyundai',
			model: 'Tucson',
			color: 'green',
			owner: 'Jin Soo'
		});
		cars.push({
			make: 'Volkswagen',
			model: 'Passat',
			color: 'yellow',
			owner: 'Max'
		});
		cars.push({
			make: 'Tesla',
			model: 'S',
			color: 'black',
			owner: 'Adriana'
		});
		cars.push({
			make: 'Peugeot',
			model: '205',
			color: 'purple',
			owner: 'Michel'
		});
		cars.push({
			make: 'Chery',
			model: 'S22L',
			color: 'white',
			owner: 'Aarav'
		});
		cars.push({
			make: 'Fiat',
			model: 'Punto',
			color: 'violet',
			owner: 'Pari'
		});
		cars.push({
			make: 'Tata',
			model: 'Nano',
			color: 'indigo',
			owner: 'Valeria'
		});
		cars.push({
			make: 'Holden',
			model: 'Barina',
			color: 'brown',
			owner: 'Shotaro'
		});

		for (let i = 0; i < cars.length; i++) {
			cars[i].docType = 'car';
			await stub.putState('CAR' + i, Buffer.from(JSON.stringify(cars[i])));
			console.info('Added <--> ', cars[i]);
		}
		console.info('============= END : Initialize Ledger ===========');
	}

	async createCar(stub, args) {
		console.info('============= START : Create Car ===========');
		if (args.length != 5) {
			throw new Error('Incorrect number of arguments. Expecting 5');
		}

		var car = {
			docType: 'car',
			make: args[1],
			model: args[2],
			color: args[3],
			owner: args[4]
		};

		await stub.putState(args[0], Buffer.from(JSON.stringify(car)));
		console.info('============= END : Create Car ===========');
	}

	async queryAllCars(stub, args) {

		let startKey = 'CAR0';
		let endKey = 'CAR999';

		let iterator = await stub.getStateByRange(startKey, endKey);

		let allResults = [];
		while (true) {
			let res = await iterator.next();

			if (res.value && res.value.value.toString()) {
				let jsonRes = {};
				console.log(res.value.value.toString('utf8'));

				jsonRes.Key = res.value.key;
				try {
					jsonRes.Record = JSON.parse(res.value.value.toString('utf8'));
				} catch (err) {
					console.log(err);
					jsonRes.Record = res.value.value.toString('utf8');
				}
				allResults.push(jsonRes);
			}
			if (res.done) {
				console.log('end of data');
				await iterator.close();
				console.info(allResults);
				return Buffer.from(JSON.stringify(allResults));
			}
		}
	}

	async changeCarOwner(stub, args) {
		console.info('============= START : changeCarOwner ===========');
		if (args.length != 2) {
			throw new Error('Incorrect number of arguments. Expecting 2');
		}

		let carAsBytes = await stub.getState(args[0]);
		let car = JSON.parse(carAsBytes);
		car.owner = args[1];

		await stub.putState(args[0], Buffer.from(JSON.stringify(car)));
		console.info('============= END : changeCarOwner ===========');
	}
};

shim.start(new Chaincode());