问题描述
var _ = require(’lodash’); var redis = require('redis'); var cheerio = require(’cheerio’); var router = require(’koa-router’)(); var superagent = require(’superagent’); let eventproxy = require(’eventproxy’); var ep = new eventproxy(); let rets = [] var client = redis.createClient(); client.on('error', function (err) { console.log('Error ' + err); }); router.get(’/’, async function (ctx, next) { let keys = JSON.parse(ctx.query.key).split(’,’).reverse() let kVals = []; keys.forEach(key=>{ let url = encodeURI(`http://news.baidu.com/ns?cl=2&rn=20&tn=news&word=${key}`) superagent.get(url) .end((err,res)=>{ console.log(`fetch------${key}------successful-----`) let $ = cheerio.load(res.text) let datas = Array.from($('.result')).splice(0,5) for (var i = datas.length - 1; i >= 0; i--) { let data = { title:$(datas[i]).find(’.c-title’).text(), author:$(datas[i]).find(’.c-author’).text(), summary:$(datas[i]).find(’.c-summary’).text() } kVals.unshift(data) } ep.emit(’news’,kVals) }) })ep.after(’news’,keys.length,rets=>{ rets = rets.map(ret=>{ return(ret) }) }) ctx.state = { title: ’数据搜索结果页’, ret:ret//如何获取异步的信息？ }; await ctx.render(’results’); }) module.exports = router;
问题解答
回答1：这个使用异步流程控制库 async 就可以了
async.map([’file1’,’file2’,’file3’], fs.stat, function(err, results) { // results is now an array of stats for each file});
