我做了一个投票应用程序,现在我试着检查用户是否已经投票给当前的投票。 我的问题我认为是一个回调函数,它不工作在我想要的时间。 我尝试了很多方法并阅读了很多关于回调和同步函数的知识,但仍不知道如何解决这个问题。
现在代码(都在同一条路线后):回调函数问题 - javascript/node.js
在这里,我找到了民意调查用户投票:
Poll.findById(req.params.id,function(err, poll){ //Find the Poll
if(err){
console.log("Vote(find the Poll) post err");
}
var test = function(poll,req){ //check if user already vote to the poll
if(req.user.local){//if it`s auth user
console.log("test");
User.findById(req.user._id,function(err, userFound){
if(err){
console.log("[checkVoted] Error findById");
}
for(var i=0;i<userFound.local.vote.poll_voted.length;i++){//run on poll_voted array
console.log("test for");
if(poll._id == userFound.local.vote.poll_voted[i]){
console.log("**return 1**");
return 1;//User already voted to this poll
}
}//end for
console.log("test return 0");
return 0;//user not voted
});//end user find
} else{ //anonmey user
console.log("[checkVoted] ELSE!");
return false;
}//else end
};//function end
后,我打电话给在这里测试功能:
**if(test(poll,req))**{ //If user already voted, redirect
console.log("already vote");
res.redirect("/poll/"+poll._id);
}**else**{//User not voted.
console.log("test Else not voted");
User.findById(req.user._id, function(err, user) {//find the id and save in voted poll
if(err){
console.log("[VOTE>POST>User.findByID ERROR");
} else{
user.local.vote.poll_voted.push(poll._id);
user.save(function(err){
if(err){
console.log("save user._id in poll_voted ERORR");
}});
}});//end User.findById
var options = poll.options;
var optionIndex = _.findIndex(options,["id", req.params.option_id]);
poll.options[optionIndex].vote++;
poll.save(function(err){
if(err){
console.log("save vote error");
} else{
res.redirect("/poll/"+poll._id);
}
});
}//end of else
});//end of Poll findById
现在用户选择选项并进行投票,其输入功能并记录“返回1”(标记),但不会进入IF(标记),也不会进入其他(已执行)...我做错了什么?
编辑: 我试试这个方法,从日志它`工作,但我现在已经antoher错误: 编辑2: SOLVED.this代码:(感谢所有)
router.post("/poll/:id/:option_id", function(req, res){
Poll.findById(req.params.id,function(err, poll){ //Find the Poll
if(err){
console.log("Vote(find the Poll) post err");
}
var test = function(poll,req, callback){
var flag=0;
if(req.user.local){//if it`s auth user
console.log("test");
User.findById(req.user._id,function(err, userFound){//look for id user
if(err){
console.log("[checkVoted] Error findById");
}
for(var i=0;i<userFound.local.vote.poll_voted.length;i++){//runnig on poll_voted array
console.log("test for");
if(poll._id == userFound.local.vote.poll_voted[i]){
console.log("**return 1**");
flag=1;//User already voted to this poll
}
}{//end for
console.log("test return 0");
callback(flag);
}});//end user find
}//end if auth user
};//test function end
test(poll, req, function(param){
if(param){
console.log("already vote");
res.redirect("/poll/"+poll._id);
} else{
console.log("test Else not voted");
User.findById(req.user._id, function(err, user) {//find the id and save in voted poll
console.log("user findbyid succes");
if(err){
console.log("[VOTE>POST>User.findByID ERROR");
} else{
console.log("user findbyid succes else");
user.local.vote.poll_voted.push(poll._id);
user.save(function(err){
if(err){
console.log("save user._id in poll_voted ERORR");
}});
}});//end User.findById
console.log("user save the vote start");
var options = poll.options;
var optionIndex = _.findIndex(options,["id", req.params.option_id]);
poll.options[optionIndex].vote++;
poll.save(function(err){
if(err){
console.log("save vote error");
} else{
console.log("user save the vote finsh");
res.redirect("/poll/"+poll._id);
}});
}});
});
});
Error: Can't set headers after they are sent
的可能的复制[如何返回从一个异步调用的响应?](https://stackoverflow.com/questions/14220321/how-do-i-return-the-an-asynchronous-call) –
谢谢你,但我读过这篇文章,尝试一些方法,但现在仍然有效。 –
然后你应该再读一遍。你仍然试图从异步调用返回,这是没有道理的。 –