http - content-type wasn send by setting it with header() in php -

i have problem setting content-type php function header(); complete code doesn't ever send output. response-object it. before every output send headers. depending on accept-header set content-type , right output, in easy way looks that:

switch($aceptheader){    case 'text/html':    #and othe stupid acept-headers of ie     $this->setheader('content-type: text/html; charset=".."');     $this->sendheaders();     $this->senddefault();     break;   case 'application/json':     $this->setheader('content-type: application/json');     $this->sendjson();     break;     case 'application/xml':     $this->setheader('content-type: application/xml');     $this->sendxml();     break; } 

the method setheader fills array, wicht put foreach-loop header(); function. not important, cause tried in direct way changing $this->setheader() header('content-type..'); has got same result (later) output ist rendering of array twig template. output. setting of headers not problem. positive result, when print_r(header_list());. there see header set before. see same response header in every browser, not in every: ie8 shows me html-code string in body after pre-tag. reason, why tested page w3c validator (and other tools). showed same result:

they no content-type header

what mistake? there mistake before set header? - id no wild inlcude stuff or else - setting of header make no trouble - headers change in models between request , response http status, wich followed $response-send(); in every time.

could there manipulation of header while rendering twig-template?

the question is: disturb setting of content-type header header() function?

an interesting thing ist: put following code begining of index.php

header('content-type: text/html'); echo 'test'; exit; 

and green test validation tool. header send.

i go throught whole code , loose header, long long way. there has had same problem or imagine have done wrong?

this look-a-like example. switch block not problem, sendheader not, too. cause replaced them in different cases whole afternoon setting header directly - every time same result.

i used these output switch different cases , works fine every time. send json, header $.ajax() of jquery accepts json , not string. produced xml restful api, works fine , sends data in format wanted it. validator tool , ie8 doesn't it. , don't understand why...

switch($aceptheader){    case 'text/html':    #and othe stupid acept-headers of ie     $this->setheader('content-type: text/html; charset=".."');     $this->sendheaders();     $this->senddefault();     break;   case 'application/json':     $this->setheader('content-type: application/json');     $this->sendjson();     break;   case 'application/xml':     $this->setheader('content-type: application/xml');     $this->sendxml();     break; } 

forgot breaks in tell code when try next case.