在异步加载时不等待值加载到ngOnInit中

Question

以下是组件：

import { Component, OnInit } from '@angular/core';
import { imageApi } from 'app/apis';

import { default as Web3} from 'web3';
import { default as contract } from 'truffle-contract'

import store_artifacts from 'build/contracts/Store.json'

import { LogService } from 'app/services';

@Component({
    selector: 'bcs-app',
    templateUrl: './bcs.component.html',
    styleUrls: [
        './bcs.component.scss'
    ]
})
export class BcsComponent implements OnInit {        
    public accounts: any[] = [];
    public account: any;
    private _web3: any;

    public Store: any;
    constructor(private logger: LogService) { }
    public ngOnInit() {
      console.log('BCS component loaded');//prints as expected
      this.initWeb3();
      this.Store = contract(store_artifacts);
      this.Store.setProvider((window as any).web3.currentProvider);
      this._web3 = (window as any).web3;
      this._web3.eth.getAccounts((err, accs) => {
          if (err != null) {
            alert("There was an error fetching your accounts.");
            return;
          }
          if (accs.length == 0) {
            this.account = "Couldn't get any accounts"
          } else{
            this.accounts = accs;
            this.account = (accs.length == 1)?this.accounts : this.accounts[0];
          }
          console.log(this.account);//<= Here value exists
        });
    }

    public initWeb3() {
      // some code
    }
}

模板是这样的：

                <div class="well">
                  Your account: {{account}}
                </div>

在UI上无需渲染