REST API Gateway Samples

pragma solidity >0.4.24;

contract SimpleStorage {

    event ValueChanged(address indexed author, string oldValue, string newValue);

    string storedValue;

    constructor(string memory newValue) public {
        emit ValueChanged(msg.sender, storedValue, newValue);
        storedValue = newValue;
    }

    function getValue() public view returns (string memory value) {
        return storedValue;
    }

    function setValue(string memory newValue) public {
        emit ValueChanged(msg.sender, storedValue, newValue);
        storedValue = newValue;
    }
}

npm install swagger-client request-promise-native

const request = require('request-promise-native')
const filePath = "./simplestorage.sol";
const fs = require('fs')
const Swagger = require('swagger-client');
const {URL} = require('url');

const NODE_URL = `https://YOURENV-YOURNODE-connect.us0-aws.kaleido.io`;
const FROM_ADDRESS = "CHANGE ME";
const USERNAME = "CHANGE ME";
const PASSWORD = "CHANGE ME";

function authHelper(username, password) {
  return req => {
    req.headers.authorization = `Basic ${Buffer.from(`${username}:${password}`).toString("base64")}`;
  }
}
async function deploy() {

  // Teach the REST API Gateway about our solidity code
  const url = new URL(NODE_URL);
  url.username = USERNAME;
  url.password = PASSWORD;
  url.pathname = "/abis";
  const req = request.post({
    url: url.href,
    qs: { compiler: "0.5" }
  });
  req.form().append("file", fs.createReadStream(filePath));

  // Retrieve a Gateway API that can:
  // - get data from any existing deployed contract that conforms to the ABI
  // - deploy new instances of the contract
  // - subscribe for events that match the signatures in this ABI (globally or on specific instances)
  console.log('Generating Gateway API');
  const { openapi } = await req.json();

  // Create a Swagger client for the OpenAPI specification we just downloaded
  console.log('Downloading OpenAPI defintion for Gateway API');
  let client = await Swagger(openapi, {
    requestInterceptor: authHelper(USERNAME,PASSWORD) // Include security credentials
  });

  // Invoke the constructor with arguments to deploy a new instance
  console.log('Deploying Contract Instance via Gateway API');
  const deploy = await client.apis.default.constructor_post({
    body: {
      // Here we set the constructor parameters
      newValue: "11111111"
    },
    "kld-from": FROM_ADDRESS
  });

  // Retrieve the address of the deployed contract
  let {contractAddress} = deploy.body;

  // Query the contract using the Gateway API (that can talk to any contract)
  console.log('Getting initial value via the getValue() method of the contract');
  const result = await client.apis.default.getValue_get({address: contractAddress});
  console.log(`Initial Value: ${JSON.stringify(result.body)}`);

  // Update the conract by submitting a transaction
  console.log('Setting value via the setValue() method of the contract');
  const resultPost = await client.apis.default.setValue_post({
    body: {
      newValue: "22222222"
    },
    "kld-from": FROM_ADDRESS,
    "kld-sync": "true", // Block waiting for the response, rather than using full TX streaming
    address: contractAddress,
  });
  console.log(`Update TX hash: ${JSON.stringify(resultPost.body.transactionHash)}`);

  // Query the value again from the contract
  const resultNew = await client.apis.default.getValue_get({
    address: contractAddress
  });
  console.log(`Updated Value: ${JSON.stringify(resultNew.body)}`);

}
deploy().catch(err => {
  console.error(err.stack);
  process.exit(1);
});