小编Var*_*ath的帖子

我试图从Firebase获取数据并将其设置为Class中的变量.我面临的问题是ngAfterViewInit()中的变量未定义.

我知道它是在ngOnInit()中设置的.我已经在Angular文档页面中阅读了Angular生命周期方法和英雄之旅示例,看看我是否正确获取数据,但它仍然无法解释这种奇怪的行为(至少对我而言!).

ngOnInit() {
    this.http.get('https://xxxxxxxx-xxxxx.firebaseio.com/data.json').map(response => response.json())
    .subscribe(
    data => {
      for (var i = 0; i < data.length; i++) {
        var a: string = data[i]['date'];
        data[i]['date'] = new Date(a);
      }
      this.timeline = data; // declared in class
      this.timelineElements = data; // declared in class
      console.log(data); // data is not empty
      console.log(TIMELINE); // data is not empty
    },
    error => {
      console.log(error);
    }
  )}


ngAfterViewInit() {
    console.log(this.timeline); // Undefined if fetched from firebase. Works perfectly if the data is fetched …

这些是webpack.config.js文件的内容

var webpack = require('webpack');
var path = require('path');

process.env.NODE_ENV = process.env.NODE_ENV || 'development';
module.exports =  {
  entry: [
  'script!jquery/dist/jquery.min.js',
  'script!foundation-sites/dist/foundation.min.js',
  './app/app.jsx'
  ],
  externals:{
    jquery: 'jQuery'
  },
  plugins:[
  new webpack.ProvidePlugin({
    '$': 'jquery',
    'jQuery': 'jquery'
  }),
  new webpack.optimize.UglifyJsPlugin({
    compressor: {
      warnings: false
    }
  })
  ],

  output: {
    path: __dirname,
    filename: './public/bundle.js'
  },
  resolve:{
    root: __dirname,
    modulesDirectories: [
    'node_modules',
    './app/components',
    './app/api'
    ],
    alias: {
        app: 'app',
        applicationStyles:'app/styles/app.scss',
        actions:'app/actions/actions.jsx',
        reducers:'app/reducers/reducers.jsx',
        configureStore:'app/store/configureStore.jsx'

      },
    extensions: ['','.js',['.jsx']]
  },
  module:{
    loaders: [
    {
      loader: 'babel-loader',
      query: { …