nodejs变量未传递给内部函数

Question

So I have written the code below but am not able to get the inner function .each to be able to call res.write with the results from the MongoDB query.

I initially believed that the problem could be due to the fact that the variable res was not global, but even after trying it as a global variable it still did not work, and it being global or not should not affect the code because the .each function is inside of the showSidebarData function that is being passed the res string.

function showSidebarData(res){
  res.writeHead(200, {'Content-Type': 'text/html'});
  coll.find({}, function(err, cursor) {
    item = new Array();
    cursor.each(function(err, doc) {
      if(doc!==null){
        item.push(doc);
      }else{
        var data = {
          "item": item
        };
        fs.readFile('/usr/share/node/pathtofile.html', 'utf8', function(err, html){
          if (err) {
            console.log(err);
          }
          res.write(dispatcher.templateEngine(html, data));
        });
      }
    });
  });
}

My goal is to be able to write the results from the template engine function inside the file read to the data stream inside of res . As a side note, the else statement for if(doc!==null) is always run after all the collection query results have been iterated over.

Answer 1

the function that was calling showSidebar() was using the correct scope but because of the nature or javascript the respose was being closed before the file stream was done reading the file and wanted to write to res . the solution was to comment out res.end() in the code below.

dispatcher.onGet("/admin/leftSidebar", function(req, res) {
        if(req.params.cookies.session=="session-key"){
showSidebarData(res);

}else{
 res.write("sorry but your username and/or password was invalid please go try brute forcing someone elses site");   
}
// commenting out the line below makes this code work 
    res.end();
});

I would like to thank @johnnyHK for the help.