Node.js Twitter API游标 [英] Node.js Twitter API cursors

问题描述

我正在使用 npm-twit 来获取特定帐户的关注者。

I'm using npm-twit to get followers of a specific account.

Twitter API从单个GET请求返回最多5000个结果。

The Twitter API returns up to 5000 results from a single GET request.

如果我查询的用户有超过5000个关注者，则返回带有数据的next_cursor值。

If the user I'm querying has over 5000 followers a "next_cursor" value is returned with the data.

要获得接下来的5000个结果，我需要重新运行GET函数，并将next_cursor值作为参数传递给它。我似乎无法理解如何做到这一点。

To get the next 5000 results, I need to re-run the GET function, passing it the "next_cursor" value as an argument. I just can't seem to work out how to do it.

我在想一个while循环，但是我无法重置全局变量，我认为是因为范围：

I was thinking a while loop, but I can't reset the global variable, I think because of scope:

var cursor = -1

while ( cursor != 0 ) { 

  T.get('followers/ids', { screen_name: 'twitter' },  function (err, data, response) {

  // Do stuff here to write data to a file

  cursor = data["next_cursor"];

  })

}

显然我不是JS的天才，所以任何帮助都会非常感激。

Obviously I'm not a JS genius, so any help would be much appreciated.

推荐答案

您遇到的问题是由于Node.js 异步。

The issue you are having is due to Node.js being asynchronous.

T.get('followers/ids', { screen_name: 'twitter' },  function getData(err, data, response) {

  // Do stuff here to write data to a file

  if(data['next_cursor'] > 0) T.get('followers/ids', { screen_name: 'twitter', next_cursor: data['next_cursor'] }, getData);

  })

}

请注意：

1. 我给内部回调函数命名。这样我们就可以从内部递归调用它。


2. 循环被替换为递归回调。


3. 如果有next_cursor数据，然后我们使用相同的函数 getData 调用 T.get 。

1. I gave a name to the internal callback function. That is so that we can recursively call it from the inside.
2. The loop is replaced with a recursive callback.
3. If there is a next_cursor data, then we call T.get using the same function getData.

请注意这里的东西代码将被执行多次（与下一个游标一样多）。因为它是递归回调 - 订单是有保证的。

Be aware that Do stuff here code will be executed many times (as many as there are next cursors). Since it is recursive callback - the order is guaranteed.

如果你不喜欢递归回调的想法，你可以通过以下方式避免它：

If you do not like the idea of recursive callbacks, you can avoid it by:

1. 如果可能，事先找出所有 next_cursor ，并使用 for loop。


2. 或者，使用异步辅助模块，如异步（虽然出于学习目的，我会避免使用模块，除非你已经熟悉这个概念）。

1. Finding out beforehand all the next_cursor's if possible, and generate requests using for loop.
2. Alternatively, use asynchronous-helper modules like Async (though for learning purposes, I would avoid modules unless you are fluent in the concept already).

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