Codeigniter header() error

Question

I have run into this problem in my Codeigniter app:

A PHP Error was encountered
Severity: Warning
Message: Cannot modify header information - headers already sent by (output started at /application/controllers/training.php:1)
Filename: libraries/Session.php
Line Number: 671

I have been checking for whitespaces and I am not sending headers.

The ONLY way this error appears is when I am updating the view and controller files.

My code ran fine until I updated some files, then the error (above) refuses to disappear.

When I clear my cache and log back in again, the error doesn't show.

Does anyone know why?

@JamWaffles: Still doesn't make much sense, the user is asking about a header error, not xml — Cyclone
– Cyclone, Commented Sep 13, 2011 at 21:52
Swear to Cthulhu, next person asking a question about "headers already sent by" will get a downvote and a closevote. RTFM dangit. — NullUserException
– NullUserException, Commented Sep 13, 2011 at 21:54

Timur · Accepted Answer · 2011-09-13 21:59:07Z

2

May be UTF-8 BOM marker? Try saving training.php without BOM (if exists)

answered Sep 13, 2011 at 21:59

Timur

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4 Comments

Kevin Simper Over a year ago

I am going to try that now, but how what that help? Just asking out of curiosity, because you must think it could be a reason.

Kevin Simper Over a year ago

I think you solved my problem! I never heard of BOM, but then i search for it, and find out that it can cause header already send! stackoverflow.com/questions/2558172/… "BOM would cause Headers already sent error, so, you can't use BOM in PHP files" - Now i have to create all my files again, damm.

Timur Over a year ago

This is a common problem... So, have you tried to save your file without BOM? Is this solved your issue?

Syed Abdul Qadeer Over a year ago

someone should give bounty for this answer.

Cyclone · Accepted Answer · 2011-09-13 21:39:46Z

0

I'm not sure why it would appear and disappear like that, but you're sending output in /application/controllers/training.php on line one, which means that any script run after that cannot modify the header. Essentially, something is invoking CI's session library in a way which is modifying the header, but the header's been sent. It'd be helpful if we could see line one of training.php.

answered Sep 13, 2011 at 21:39

Cyclone

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Comments

Paweł Tomkiel · Accepted Answer · 2015-03-14 12:23:00Z

0

I have checked for whitespaces, none. I am not using session yet, i am only setting it to session variables in the login script. The ONLY place i use it.

training.php:

<?php

class Training extends CI_Controller
{

    public function index()
    {
        $data['heading'] = 'Træning';
        $data['smallheading'] = 'Registre dine træningsture og hold styr på dem.';
        $this->load->view('header_view', $data);
        $this->load->view('training_view');
        $this->load->view('footer_view');
    }

}

In the different views there is only echoing php variables and HTML.

edited Mar 14, 2015 at 12:23

Paweł Tomkiel

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answered Sep 14, 2011 at 8:18

Kevin Simper

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