node.js - Error: Can't set headers after they are sent in node js MVC approach -


i getting following error ...

   events.js:160      throw er; // unhandled 'error' event      ^  error: can't set headers after sent.       @ serverresponse.outgoingmessage.setheader (_http_outgoing.js:357:11)       @ serverresponse.header        (c:\level3proj\node_modules\express\lib\response.js:730:10)

.. when execute following code

    var mongoose = require('mongoose');     var express = require('express');      // express router used define routes     var userrouter= express.router();      var usermodel = mongoose.model('user');     var allusers = [];     var fs = require('fs');      module.exports.controller = function(app) {       userrouter.get('/all',function(req,res) {         res.send("this route information on particular ");         usermodel.find({},function(err,allusers) {           if(err) {             res.send(err);           } else {             res.send(allusers);           }         }); // end user model       }); // end users       app.use('/users', userrouter);     } // end controller code

when load

http://localhost:3000/users/all

the result presented , @ same throwing error in console.

why getting error on console?

you send responce 2 times. first 1 here

 res.send("this route information on particular ");

and after here

if(err) {     res.send(err); } else {     res.send(allusers); }

remove first sending , responce work


Comments

Post a Comment

Popular posts from this blog

Is there a better way to structure post methods in Class Based Views -

i'm using class based views in django , never specify url in ajax calls , omit action parameter in form because know these requests go through post method of class based view. notice view - profile page make many requests depending on user updating on page - post method become convoluted , if/else mess example: def post(self, request, *args, **kwargs): # handle user changing available date if request.post.get('availabledate') != none: self.updateavailabledate(request) return jsonresponse({'result':'success'}) if request.post.get('newprojectname') != none: creative_user = creativeuserprofile.objects.get(id = request.user.id) project = project.create_project(creative_user, request.post['newprojectname']) project.save() return jsonresponse({'projectid': project.id }) if request.post.get('projectimage') != none , request.files['file']: proj...
Read more

performance - Why is XCHG reg, reg a 3 micro-op instruction on modern Intel architectures? -

i'm doing micro-optimization on performance critical part of code , came across sequence of instructions (in at&t syntax): add %rax, %rbx mov %rdx, %rax mov %rbx, %rdx i thought had use case xchg allow me shave instruction , write: add %rbx, %rax xchg %rax, %rdx however, dimay found agner fog's instruction tables , xchg 3 micro-op instruction 2 cycle latency on sandy bridge, ivy bridge, broadwell, haswell , skylake. 3 whole micro-ops , 2 cycles of latency! 3 micro-ops throws off 4-1-1-1 cadence , 2 cycle latency makes worse original in best case since last 2 instructions in original might execute in parallel. now... cpu might breaking instruction micro-ops equivalent to: mov %rax, %tmp mov %rdx, %rax mov %tmp, %rdx where tmp anonymous internal register , suppose last 2 micro-ops run in parallel latency 2 cycles. given register renaming occurs on these micro-architectures, though, doesn't make sense me done way. why wouldn't register renamer ...
Read more

c# - Asp.net web api : redirect unauthorized requst to forbidden page -

im trying redirect unauthorized request forbidden page instead i'm getting forbidden page in response body , how can fix ? here's startup class : app.createperowincontext(storecontext.create); app.createperowincontext<applicationusermanager>(applicationusermanager.create); app.createperowincontext<applicationsigninmanager>(applicationsigninmanager.create); app.usecookieauthentication(new cookieauthenticationoptions { authenticationtype = defaultauthenticationtypes.applicationcookie, expiretimespan = timespan.fromdays(30), }); app.useexternalsignincookie(defaultauthenticationtypes.externalcookie); app.usetwofactorsignincookie(defaultauthenticationtypes.twofactorcookie, timespan.fromminutes(5)); app.usetwofactorrememberbrowsercookie(defaultauthenticationtypes.twofactorrememberbrowsercookie); the method im trying reach : [httpget] [authorize(roles = "admin")] public string getcurrentusername() { return userman...
Read more