nkn实现频道聊天功能

1.创建一个nkn客户端

import NKN from 'nkn-multiclient';

const nknClient = new NKN({
    identifier: "any thing"
});

2.创建一个钱包

import nknWallet from 'nkn-wallet';
const seed = "64位字符串";
const wallet = nknWallet.restoreWalletBySeed(seed, 'password');

钱包和客户端建立联系

import rpcCall from 'nkn-client/lib/rpc';

nknWallet.configure({
    rpcAddr: 'https://ip:port',// 用于转发成nkn节点的地址
});

const client = nkn({
    originalClient: true,
    identifier: 'identifier',
    seed: wallet.getSeed(),
    seedRpcServerAddr: 'https://ip:port',
});

4.用钱包订阅一个主题

wallet.subscribe('topic', 5000, 'identifier') // 主题，订阅主题的有效时长（区块大小），对应客户端的 identifier
.then(function(data) {
    console.log('Subscribe success:', data, '');
}).catch(function(error) {
    console.log('Subscribe fail:', error);
});

5.发送信息以及接收信息

client.on('connect', ()=>{
    client.on('message', (src, payload, payloadType, encrypt) => {
        console.log( payloadType + 'Receive', encrypt ? 'encrypted' : 'unencrypted',  'message', '"' + payload + '"','from', src, 'afterms');
        // Send a text response
        return 'Well received!';
    });
})

client.publish("topic", 'hello world', { txPool: true });

6.获取当前订阅主题的区块高度以及最近的区块高度

const latestBlockHeight = rpcCall(
	'https://ip:port',
	'getlatestblockheight',
);
const subinfo = client.defaultClient.getSubscription('topic', client.addr)

Promise.all([subinfo,latestBlockHeight]).then(([info, blockheight])=>{
    if(info.expiresAt - blockheight > 5000){
        return Promise.reject('Too soon.');
    }else{
        wallet.subscribe('topic', 5000, 'identifier');
    }
})

7.获取订阅频道的人数

	client.defaultClient.getSubscribers('tpoic', options); // options = {offset: 0,limit: 1000, meta: false, txPool: true};