let API_HOST = "http://xxx.com/xxx";
let DEBUG = true;//切换数据入口
var Mock = require('mock.js')
function ajax(datahttps://www.wxapp-union.com/= '', fn, method = "get", header = {}) {
    if (!DEBUG) {
        wx.request({
            url: config.API_HOST + data,
            method: method ? method : 'get',
            data: {},
            header: header ? header : { "Content-Type": "application/json" },
            success: function (res) {
                fn(res);
            }
        });
    } else {
        // 模拟数据
        var res = Mock.mock({
            'error_code': '',
            'error_msg': '',
            'data|10': [{
                'id|+1': 1,
                'img': "@image('200x100', '#4A7BF7','#fff','pic')",
                'title': '@ctitle(3,8)',
                'city': "@county(true)",
                'stock_num': '@integer(0,100)',//库存数量  
                'marketing_start': '@datetime()',
                'marketing_stop': '@now()',
                'price': '@integer(100,2000)',//现价，单位：分  
                'original_price': '@integer(100,3000)'
            }]  
        })
        // 输出结果
       // console.log(JSON.stringify(res, null, 2))
        fn(res);
    }
}
module.exports = {
    ajax: ajax
}

//index.js
//获取应用实例
var app = getApp()
var API = require('../../utils/api.js')
Page({
    data: {
    },
    onLoad: function () {
        console.log('onLoad')
        var that = this
        // 使用 Mock
        API.ajax('', function (res) {
            //这里既可以获取模拟的res
            console.log(res)
            that.setData({
                list:res.data
            })
        });

        console.log(this.data.list)
    }
})

<!--index.wxml-->
<block wx:for="{{list}}" wx:key="name">
  <view>{{item.title}}</view>
  <text>{{item.city}}</text>
  <view>
    <text>{{item.marketing_start}}</text>
  </view>
  <image src='https://www.wxapp-union.com/{{item.img}}'></image>
</block>