Chrome Plugin

Integrating the Google Chrome Cyano wallet plugin

Before using the dAPI for Chrome, it is necessary to first install and implement a wallet that has the dAPI provider functionality built into it, for e.g., Cyano Wallet for Chrome.

The dAPI can be implemented using TypeScript, and can also be used in JavaScript programs.

Some of the more popular usage channels of dApps, apart from opening the dApp in the Chrome browser, also consist of launching the dApp from withing the mobile wallet. The access scheme for opening a dApp in the wallet is illustrated here.

Here is a step by step guide to assist developers with the integration process:

1. Development environment set-up and installation

Before starting with the actual development process, do ensure that the following tools are installed and set-up on your local machine.

• Node.js v6+ (LTS with npm) - Download link

• Google Chrome - Download link

• Cyano Wallet Chrome Plugin - Download link

• Git - Download link

Next, we can install Ontology's dAPI. While building dApps, this dAPI serves as one of the core APIs that allow us to communicate with the chain. The source code can be downloaded here. To carry out the installation using npm, use the following shell command:

npm install ontology-dapi

2. Creating a dAPI instance

Creating a dAPI instance involves importing and registering the client-side, as such:

import { client } from 'ontology-dapi';
client.registerClient({});

3. Deploying dAPI methods

Once a dAPI instance is created successfully, dAPI methods can be used in a given dApp.

Fetching account or identity information

account = await client.api.asset.getAccount()
res = await client.api.identity.getIdentity();

Smart contract methods

const result = await client.api.smartContract.invoke({contract,method,parameters,gasPrice,gasLimit,requireIdentity});
const result = await client.api.smartContract.invokeRead({ contract, method, parameters });
const result = await client.api.smartContract.deploy({code,name,version,author,email,description,needStorage,gasPrice,gasLimit});

Communication methods that assist interaction with the chain

const network = await client.api.network.getNetwork();
const height = await client.api.network.getBlockHeight();
const block = await client.api.network.getBlock({ block: 1 });
const transaction = await client.api.network.getTransaction({txHash: '314e24e5bb0bd88852b2f13e673e5dcdfd53bdab909de8b9812644d6871bc05f'});
const balance = await client.api.network.getBalance({ address: 'AcyLq3tokVpkMBMLALVMWRdVJ83TTgBUwU' });

Account transfer method

const result = await client.api.asset.makeTransfer({ recipient, asset, amount });

Data signature methods

const message: string = values.message;
const signature: Signature = {
  data,
  publicKey
};
const result = await client.api.message.signMessage({ message });
const result = await client.api.message.verifyMessage({ message, signature });

For a comprehensive list of all the available dAPI methods, please refer to the dAPI Specification.

4. dAPI demonstration

Follow the link below to refer to a demo dApp that utilizes the dAPI methods mentioned above.

Using the dAPI

How to set the gaslimit and gasprice

Every transaction that takes place on the chain includes a gaslimit and gasprice.

gasprice has a correlation with the amount of standby time while the given transaction is packaged. Currently, the lowest value of gasprice is 500 units on the TestNet and MainNet.

The gaslimit of deployment contracts is set based on the complexity of smart contract's execution process. The minimum gaslimit value of a contract can be determined before deploying it by carrying out a pre-execution. The default gaslimit value of native contracts is 20000, while that of deployment contracts is usually higher than 20000000 units, generally speaking.

How to handle addresses

The Chrome plugin Cyano wallet only accepts addresses in ByteArray format when importing addresses. While testing smart contracts in SmartX, the IDE automatically converts addresses to ByteArray format. So, there will be no address related issues during the deployment phase. However, in the developer's local environment, if the conversion is not carried out manually, the system will return an error.

The following method can be used to convert addresses to ByteArray format in JavaScript:

import {Crypto} from 'ontology-ts-sdk';
var address = new Crypto.Address(account).serialize() //The "address" assigned here is in ByteArray format