将附加参数传递给Javascript回调函数 [英] Pass additional parameter to Javascript callback function

问题描述

我需要在Node.JS应用程序中观看少量目录：

 函数已更新（event，filename） {
 log（CHANGED\t / share / channels /+ filename）; 
} 
 for（i in channels）
 fs.watch（'share / channels /'+ channels [i]，{persistent：false}，updated）;问题是fs.watch只传递文件名到回调函数，而不包括它的目录​​。有没有办法我能以某种方式传递一个额外的参数到updated（）函数，所以它知道文件的位置？
 
 
 
我想我正在寻找类似于Python的 functools.partial ，如果这有助于任何。
解决方案
您可以使用  Function.bind  ：
 函数已更新（extraInformation，event，filename）{
 log \t / share / channels /+ extraInformation + filename）; 
} 
 
 for（i in channels）
 fs.watch（'share / channels /'+ channels [i]，{persistent：false}，
 updated .bind（null，'wherever / it / is /'））; 
  
 
I need to watch a small number of directories in a Node.JS application:
function updated(event, filename){
    log("CHANGED\t/share/channels/" + filename);
}
for(i in channels)
    fs.watch('share/channels/' + channels[i], {persistent: false}, updated);
The problem is that fs.watch only passes the filename to the callback function, without including the directory it's in. Is there a way I can somehow pass in an extra parameter to the updated() function so it knows where the file is?

I think I'm looking for something similar to Python's functools.partial, if that helps any.
解决方案
You can use Function.bind:
function updated(extraInformation, event, filename) {
    log("CHANGED\t/share/channels/" + extraInformation + filename);
}

for(i in channels)
    fs.watch('share/channels/' + channels[i], {persistent: false},
              updated.bind(null, 'wherever/it/is/'));


                        
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