图API的While循环中的异步方法分页 [英] Asynchronous method in while loop with Graph API paged

问题描述

我正在使用 facebook节点sdk 来获取node.js.来自Facebook用户的信息(例如其供稿和朋友)，效果很好.

I'm using facebook node sdk for node.js to get information from a facebook user such as their feed and friends, which is working fine.

但是，在返回的数据被分页时，我遇到了问题-我需要以递归模式构建某些内容.让我解释一下:

However I'm having an issue where the returned data is paged - I need to build something in recursive mode. Let me explain:

FB.api('/me/feed?limit=5000', {
    access_token: token
}, function(response) {
  // response is an object that could have as response.paging.next attribute
}); 

限制在这里不起作用，因为它最多返回245，并返回指示下一页结果的 paging 对象.

Limit isn't working here, because it returns a max of 245 and returns paging object indicating the next page of results.

由于下一个调用取决于上一个异步调用的结果，因此我尝试执行以下操作:

Because the next call depends of the result of the previous async call, I tried to do something like this:

// first call before
var hasNext = response.paging.next ? true : false;
while (hasNext){
    FB.api('/me/feed', {
        access_token: token
    }, function(response_paged) {
       response.data.concat(response_paged.data);
       // If do not have a next page to break the loop
       if (!response_paged.paging.next) hasNext = false;
    });
} 

获取下一个令牌的方式目前并不重要

关键是我试图以递归模式进行异步调用，但是它不起作用，这样我就遇到了无限循环.

The point is I'm trying to do async calls in recursive mode, but its not working, this way I'm getting an infinite loop.

推荐答案

我用async/await解决此问题的想法:

My idea of solving this with async/await:

async function getFeed(token) {
    let feedItems = [],
        hasNext = true,
        apiCall = '/me/feed';

    while (hasNext) {
        await new Promise(resolve => {
            FB.api(apiCall, {access_token: token}, (response) => {
                feedItems.concat(response.data);
                if (!response.paging.next) {
                    hasNext = false;
                } else {
                    apiCall = response.paging.next;
                }
                resolve();
            });
        });
    }
    return feedItems;
}

getFeed().then((response) => {
    console.log(response);
});

请注意，您需要为此使用Node.js 7.9.0+: http://node.green/

Be aware that you need Node.js 7.9.0+ for this: http://node.green/

对于旧版本，请安装以下版本: https://github.com/yortus/asyncawait

For older versions, install this: https://github.com/yortus/asyncawait

您还可以使用递归函数，但是平滑/现代的方式是异步/等待.

You can also use a recursive function, but the smooth/modern way would be async/await.

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