How to create data and render within the one get request - node.js

Question

dashboardRouter.route('/:Teachersubjects/:Class/:Salary')
.get(function(req,res)
{
function handleErr(err,redir)
{
if(redir){
res.end("err");
}
else{
res.writeHead(200, {"content-type": "text/plain"});
res.end('Error occured');
}
}
Verify.verifySchoolUser(req,res,function(err,schooluserId){
if(err){
res.redirect('/schoolusers/login');
return;
}
else{
SchoolUser.findOne({_id:schooluserId}).exec(function(err,schooluser){
if(err)
{
console.log("NOUSER school")
handleErr(err);
return;
}
else
{
if(schooluser.count<4){
console.log(req.params.Class);
vacancies.create(req.params,function(err,vacancy){
if(err){
console.log(err.message);
console.log(err.name);
console.log("create error");
for (field in err.errors) {
console.log(err.errors[field].message);
}
handleErr(err);
return;
}
console.log(vacancy);
schooluser.vacancies.push(vacancy._id);
schooluser.save(function(err){
if(err){
console.log(JSON.stringify(err));
handleErr(err);
}
teacherforms.find({}, function (err, teacherforms) {
if (err) throw err;
else {
var teacherforms = teacherforms;
console.log(teacherforms);
var arr=[];
for(i=0; i<teacherforms.length; i++ ) {
arr.push(teacherforms[i]._id);
console.log(arr);
}
teacherusers.find({checking:{$in:arr}}, function (err, teacherusers){
if (err) throw err;
else{
var data =[];
for(i=0; i<teacherusers.length; i++ ) {
var kdata={};
var str = "";
kdata.firstname = teacherusers[i].firstname;
kdata.profilepic= teacherusers[i].profilepic;
kdata.experience= teacherforms[i].Teachingexperience;
var len= teacherforms[i].Qualifications.length;
console.log(teacherforms[i].Qualifications);
for(j=len-1;j>=0;j--){
if(j==0){
str = str + teacherforms[i].Qualifications[j];
}
else{
str=str + teacherforms[i].Qualifications[j] + ", ";
}
}
kdata.qualifications = str;
data.push(kdata);
}
data.push(vacancy.Class);
//data.push(vacancy.Qualification);
data.push(vacancy.Teachersubjects);
console.log(data);
res.render('../views/dashboard/dashboard_resumes.ejs',{
sdata:data
});
}
});
}
})
});
})
}
else {
res.send("Limit Exceeded");
}
}
});
}
});
});
I want to save a object firstly in MongoDB at get request and then render a page in ejs with a new object.But I am getting a error 500(Internal Server Error),so can we save a object and render the ejs page with new object at same end point?
P.S- The code below is the crucial part of the code and there is no syntax error and schooluser(object) is passed from the upper part of the code.
dashboardRouter.route('/:Teachersubjects/:Class/:Salary')
.get(function(req, res) {
vacancies.create(req.params, function(err, vacancy) {
if (err) {
console.log(err.message);
console.log(err.name);
console.log("create error");
for (field in err.errors) {
console.log(err.errors[field].message);
}
handleErr(err);
return;
}
schooluser.vacancies.push(vacancy._id);
schooluser.save(function(err) {
if (err) {
handleErr(err);
} else {
res.render('../views/dashboard/dashboard_resumes.ejs', {
sdata: data
});
}
});
});
});

Answer 1

There are multiple issues with your route handler. First, whenever an error occurs you run this through your handleErr() function, but you never do anything with res in these cases. This means that the request is never resolved and eventually times out on the client side.
When an error occurs, you should respond with an error code. For instance:
res.status(400).send('Something went wrong');
When you actually do send a response and render the template, you're applying a variable called data. However, this variable doesn't seem to be declared anywhere in your code. Maybe you left out that code, but if that variable is indeed undeclared, it throws a ReferenceError which is caught by the routing framework which in turn responds with a 500 Internal Server Error. So this is probably the source of your issue.
Any uncaught errors thrown by vacancies.create() or schooluser.save() would have the same effect.