LINE Blockchain Developers SDK for JavaScript

Table of Contents

• Introduction
• Getting Started
• Key objects and usage

Introduction

The LINE Blockchain Developers SDK for JavaScript makes it easy to develop a service(dApp) using LINE Blockchain Developers API, and there are no worries about generating signature for each request.

Documentation

See the official LINE Blockchain Developers API documentation for more information.

• English: https://docs-blockchain.line.biz/api-guide/
• Japanese: https://docs-blockchain.line.biz/ja/api-guide/
• Korean: https://docs-blockchain.line.biz/ko/api-guide/

Requirements

• Node.js 10 or higher

Installation

Before getting started, you need to install the library to your project. To make installation easy, use package managers as follows:

Using npm:

npm install @line/lbd-sdk-js

Using yarn

yarn add @line/lbd-sdk-js

Versioning

This project respects semantic versioning.

See http://semver.org/

Contributing

Please check CONTRIBUTING before making a contribution.

License

Copyright (C) 2021 LINE Corp.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    https://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

Getting Started

Requirements

• Node.js >= 10

  • It uses ES2017.

• npm, preferably >=7

Other dependencies are installed via npm(or yarn), and do not need to be pre-installed.

Install

All the dependencies can be install via npm or yarn

• npm

  npm install @line/lbd-sdk-js

• yarn

  yarn add @line/lbd-sdk-js

Instead of using package managers, you can clone and build from source as well. Run the following scripts/commends.

$ git clone https://github.com/line/line-blockchain-developers-sdk-js.git
$ cd line-blockchain-developers-sdk-js
$ npm install
$ npm run build

The built result will be placed in build/.

Test

You can run all the unit tests by following scripts.

npm run test

Integration tests

You can run all the integration tests by following scripts.

npm run test:integration

Note

To run integration tests, integration-test.env is required with following properties.

HOST_URL=[api-url]
SERVICE_ID=[your service-id]
SERVICE_API_KEY=[your service-api-key]
SERVICE_API_SECRET=[your service-api-secret]
OWNER_ADDRESS=[your service wallet address]
OWNER_SECRET=[your service wallet secret]
OWNER_ADDRESS2=[your another service wallet address]
SERVICE_TOKEN_CONTRACT_ID=[your service-token contract-id]
ITEM_TOKEN_CONTRACT_ID=[your item-token contract-id]
LINE_USER_ID=[your line user id]
LINE_USER_WALLET_ADDRESS=[BitMax wallet address of the user]

Basic Usage

It can be imported with CommonJS, ES2015 modules, and preferably TypeScript.

The library is written in TypeScript and includes TypeScript definitions by default. Nevertheless, it can surely be used with plain JavaScript too.

Create HttpClient

// CommonJS
const devSdk = require('@line/lbd-sdk-js');
const httpClient = new devSdk.HttpClient(BASE_URL, SERVICE_API_KEY, SERVICE_API_SECRET)

// ES2015 modules or TypeScript
import * as devSdk from '@line/lbd-sdk-js';
const httpClient = new devSdk.HttpClient(BASE_URL, SERVICE_API_KEY, SERVICE_API_SECRET)

Example to get server time

Using promise

httpClient.time().then(response => {
    console.log("statusCode", response.statusCode);
    console.log("responseTime", response.responseTime);
    console.log("statusMessage", response.statusMessage);
    console.log("responseData", response.responseData);
})

Using async function

async function checkServerTime() {
    var response = await httpClient.time();
    console.log("statusCode", response.statusCode);
    console.log("responseTime", response.responseTime);
    console.log("statusMessage", response.statusMessage);
    console.log("responseData", response.responseData);
}

Key objects and usage

HttpClient

This class represents an HTTP client to connect and interact with the LINE Blockchain Developers API server. It provides functions to call the endpoints of the API with mandatory and optional parameters. It's an entry point for this library, every dApp for LINE Blockchain Developers should have an instance of HttpClient.

Create an instance with your connection and authentication information as follows:

// Directly import
import { HttpClient } from './lib/http-client-base';
const httpClient = new HttpClient(baseUrl, apiKey, apiSecret);

// CommonJS
const devSdk = require('@line/lbd-sdk-js');
const httpClient = new devSdk.HttpClient(BASE_URL, SERVICE_API_KEY, SERVICE_API_SECRET)

// ES2015 modules or TypeScript
import * as devSdk from '@line/lbd-sdk-js';
const httpClient = new devSdk.HttpClient(BASE_URL, SERVICE_API_KEY, SERVICE_API_SECRET)

• baseUrl is the address of API server. Find one for the chain your service runs on in API guide.
• apiKey is your service's API key.
• apiSecret is your service's API secret. Never use the secret hard-coded in the source code.

Now, you can call any endpoints via the functions of the instance. A simple example is to get the server time:

(async() => {
  const response = await httpClient.time();
  console.log(response['statusCode']);
})();

Remember that you must handle it in an asynchronous way.

Request and response

When requesting, you can use predefined request data classes in lib/request.ts. Try to send a memo save request for example as follows:

//Directly import
import { MemoRequest } from './lib/request';

(async() => {
  const request = new MemoRequest('my first memo', walletAddress, walletSecret);
  const response = await httpClient.createMemo(request);
})();

When you need to parse a JSON-formatted responseData in a response, find and use the proper response data class in lib/response.ts. To get the txhash or the above request for example:

import { GenericResponse, TxResultResponse } from './lib/response';

(async() => {
  const request = new MemoRequest('my first memo', walletAddress, walletSecret);
  let response: GenericResponse<TxResultResponse> = await httpClient.createMemo(request);
  console.log(response.responseData.txhash);
})();

SignatureGenerator

This class provides a functionality to generate signatures for a request.

All API requests, except for the endpoint to retrieve the server time, must pass authentication information and be signed. Signing is a bit annoying, but never mind, fortunately, HttpClient itself will import this and generate signatures before sending a request.

If you do want to study how LINE Blockchain signature created, it's okay to dive into the source code.

New transaction result

Please refer to New transaction result