从存储调用api，并将数据绑定到ReactJS/Flux中的组件状态

Question

使用React-router-component，我设置了用一个名为gigist的组件加载我的主页，该组件如下：

var React = require('react');
var AppStore =require('../../stores/app-store.js');
var GigsListItem = require('./giglistitem.js');
var StoreWatchMixin =require('../../mixins/StoreWatchMixin.js');

function getGigs()
{

    return {items:AppStore.getGigs()}
}

var GigsList= React.createClass({
  mixins:[new StoreWatchMixin(getGigs)],
  componentWillMount:function()
  {
     this.setState(getGigs());
     console.log(this.state);
  },
  componentDidMount:function()
  {
     this.setState(getGigs());
     console.log(this.state);
  },
    render:function()
    {
        console.log("rendered view");
        var liststyle={border:'1px solid black'};

        /*
        var items=this.state.items.map(function(item)
        {
            return <GigsListItem gig={item} />
        })  */
        return (

                <div className="row" style={liststyle}>
                {this.state.items}

                </div>
               )
    }
});

module.exports=GigsList;

在控制台中，'1'是为组件giglist设置初始状态，'3'是组件将装入，'Rendered View'是在呈现组件时，'2'是ajax请求

它清楚地表明，在ajax调用之后，数据没有被设置为组件状态。

var AppDispatcher = require('../dispatchers/app-dispatcher');
var AppConstants = require('../constants/app-constants');
var reqwest = require('reqwest');
var merge = require('react/lib/merge');
var EventEmitter = require('events').EventEmitter;

var CHANGE_EVENT = "change";

var _gigs = [];

function getGigsList()
{

reqwest({url:'myapi',
type:'get',
success:function(resp)
{
  console.log(2);
  return resp.gigs;  
  //alert(JSON.stringify(_gigs));
}.bind(this)})  


}  



var _cartItems = [];


function _removeItem(index){
  _cartItems[index].inCart = false;
  _cartItems.splice(index, 1);
}

function _increaseItem(index){
  _cartItems[index].qty++;
}

function _decreaseItem(index){
  if(_cartItems[index].qty>1){
    _cartItems[index].qty--;
  }
  else {
    _removeItem(index);
  }
}


function _addItem(item){
  if(!item.inCart){
    item['qty'] = 1;
    item['inCart'] = true;
    _cartItems.push(item);
  }
  else {
    _cartItems.forEach(function(cartItem, i){
      if(cartItem.id===item.id){
        _increaseItem(i);
      }
    });
  }
}

function _CartTotals()
{
  var qty=0,total=0;
  _cartItems.forEach(function(cartItem)
    {
       qty+=cartItem.qty;
       total+=cartItem.cost * cartItem.qty;

    });
  return {'qty':qty,'total':total}
}


var AppStore = merge(EventEmitter.prototype, {
  emitChange:function(){
    this.emit(CHANGE_EVENT)
  },

  addChangeListener:function(callback){
    this.on(CHANGE_EVENT, callback)
  },

  removeChangeListener:function(callback){
    this.removeListener(CHANGE_EVENT, callback)
  },

  getCart:function(){
    return _cartItems
  },

  getGigs:function(){
    alert(JSON.stringify(getGigsList()));
    return getGigsList();
  },

  getCartTotals:function()
  {
    return _CartTotals();
  },

  dispatcherIndex:AppDispatcher.register(function(payload){
    var action = payload.action; // this is our action from handleViewAction
    switch(action.actionType){
      case AppConstants.ADD_ITEM:
        _addItem(payload.action.item);
        break;

      case AppConstants.REMOVE_ITEM:
        _removeItem(payload.action.index);
        break;

      case AppConstants.INCREASE_ITEM:
        _increaseItem(payload.action.index);
        break;

      case AppConstants.DECREASE_ITEM:
        _decreaseItem(payload.action.index);
        break;
    }
    AppStore.emitChange();

    return true;
  })
})

module.exports = AppStore;

有人能指出我哪里做错了吗？我希望我说清楚了。提前谢谢

Answer 1

不能在异步代码中使用return语句，即在Ajax-call的成功回调中。

相反，尝试检查存储中是否已经有gigs，在这种情况下，您返回它们，如果存储中没有gigs，则请求获取一些gigs，在success回调中将存储状态设置为新数据，并发出一个更改，告诉组件再次尝试获取存储状态。

    function getGigsList()
    {
        if (_gigs.length > 0) { return _gigs; } //return immediately if data exists

        reqwest({url:'myapi',
        type:'get',
        success:function(resp)
        {
            console.log(2);
            _.gigs = resp.gigs;  
            this.emit(CHANGE_EVENT);
        }.bind(this)}) 

        return _gigs; //currently an empty array. this way you don't have to check for undefined in the component, you can just iterate over it directly
    }