从回调返回值的范围内Meteor.method

问题描述

我遇到了一些我不明白流星。我有这种方法，这需要一个查询，它发送到亚马逊，然后在该函数的回调我尝试返回结果。

I am running into something I don't understand with Meteor. I have this method, which takes a query, sends it to amazon, and then in the callback of that function I try to return the results.

Meteor.methods({
    'search': function(query) {
        var bookInfo;
        if (Meteor.isServer) {
            amazon.execute('ItemSearch', {
                'SearchIndex': 'Books',
                'Keywords': query,
                'ResponseGroup': 'ItemAttributes'
            }, function(results) {
                bookInfo = results;
                console.log(bookInfo);
                return bookInfo;
            });
        }
    }
});

但是，当我把下列控制台在我的浏览器（Chrome）：

But when I put the following into the console in my browser (chrome):

Meteor.call('search', 'harry potter', function(error, response) {
    console.log('response:', response);
});

我得到这样的：

undefined
response: undefined          VM13464:3

我想我明白，第一个不确定来自于方法不返回客户端上的任何东西，但回调似乎并没有在所有的工作。

I think I understand that the first undefined comes from the method not returning anything on the client, but the callback doesn't seem to work at all.

该amazon.execute（...）绝对是返回的东西，为的console.log权的回报上面并登录我要找的信息。

The amazon.execute(...) is definitely returning something, as the console.log right above the return does log the info I'm looking for.

任何想法什么错，我该如何解决这个问题？

Any ideas what's going wrong and how I can fix it?

推荐答案

您需要使用未来，以实现自己的目标。

You need to use Future to achieve your goal.

如何使用未来，因为流星0.6？

How to use future since Meteor 0.6?

Meteor.startup(function () {
 Future = Npm.require('fibers/future');

 // use Future here
}

您使用的方法改写未来：

Your method rewritten with Future:

Meteor.methods({
 'search': function(query) {

    var future = new Future();

    amazon.execute('ItemSearch', {
            'SearchIndex': 'Books',
            'Keywords': query,
            'ResponseGroup': 'ItemAttributes'
    }, function(results) {
       console.log(results);

       future["return"](results)

    });

    return future.wait();
 }
});

现在它应该工作。

Meteor.call('search', 'harry potter', function(error, response) {
   if(error){
    console.log('ERROR :', error);
   }else{
    console.log('response:', response);
   }

});

如果您想了解更多关于未来库，我建议看

If you want to learn more about Future library I recommend watching screencast

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