怎样散布? [英] How to promisify?

问题描述

我有这种功能:

someFunction.someMethod('param1', function(err, res1, res2) {
  req.method(res1, function(err) {
    if (!err) {
      console.log('Yes!');
    }
  });
})(req, res); // <-- This one's the problem!

现在，当我尝试传播它时:

Now when I try to promisify it:

var a = Promise.promisify(someFunction.someMethod);

a('param1').spread(function(res1, res2) {
  console.log('Yes!');
}).catch(function(err) {

});

它不再工作了，因为我不能在其末尾放置(req，res).如何实现呢?

it doesn't work anymore, because I cannot put the (req, res) at the end of it. How to achieve this?

推荐答案

我会尝试这样做:

var a = Promise.promisify(function(arg, cb) {
    someFunction.someMethod(arg, cb)(req, res);
});

a('param1').spread(function(res1, res2) {
  console.log('Yes!');
}).catch(function(err) {

});

...是的，这很丑.但是，此部分应用程序可能表明 someFunction.someMethod('param1'，…)返回的函数应被多次调用；并且您的回调将被调用多次-您将无法再使用promises.

…and yes, it's ugly. This partial application might however be a sign that the function returned by someFunction.someMethod('param1', …) is supposed to be called multiple times; and your callback would be called as many times - where you cannot use promises any more.

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