javascript - 两个for循环内的node.js同步请求

Question

我想让我的代码同步，因为如果我们以异步方式发送太多请求，Google 就会阻止。

for (var i = 0; i < titles.length; i++) {
    for (var j = 0; j < filter.length; j++) {
     (function(e,u){
    console.log(titles[e]+" - "+filter[u]);
    request('http://suggestqueries.google.com/complete/search?  client=chrome&output=json&hl=tr&q='+ titles[e] +" "+filter[u] ,{"json":true,"encoding":"binary"}, function (error, response, tags) {
        console.log(tags.toString());
     });

    }(i,j));

    }
  }

这段代码工作正常，但它是异步的，我知道如何用一个循环来完成它，但我不知道如何使用两个循环。

Answer 1

您可以尝试使用async.js与 eachSeries ，像这样

var requests = [];

for (var i = 0; i < titles.length; i++) {
  for (var j = 0; j < filter.length; j++) {
    requests.push({title: titles[i], filter: filter[j]});
  }
}

async.eachSeries(requests, function (req, next) {
    request('http://suggestqueries.google.com/complete/search?client=chrome&output=json&hl=tr&q=' + req.title + " " + req.filter, {
        json: true,
        encoding: 'binary'
    }, function(error, response, tags) {
        console.log(tags.toString());

        next(error);
    });
}, function () {
  console.log('done');
});

The next iterator is only called once the current one has completed. This means the iterator functions will complete in order.