[TYPO3-english] Build HTML page in backend : I get a warning

[David Bruchmann]

----- Ursprüngliche Nachricht -----
Von:        Gregory Loichot <gloichot at cross-systems.ch>
Gesendet:   Freitag, 24. April 2009 14:14:48
An:         typo3-english at lists.netfielders.de
CC:
Betreff:    Re: [TYPO3-english] Build HTML page in backend : I get a warning
> Hello,
> 
> Thank you for your answer, but it doesn't work : I still have the 
> warning and there is no more formated style (white background, ...)
> 

Hello Gregory,

sorry, I had a look at an own class and remarked my tip was wrong.

Is it possible that a function like printContent() is called afterwards?
Due to your programmed lines the content is echoed already in the 
main-function. If you call a print-function with the same function 
afterwards it's echoed two times perhaps.

Two other reasons for the errormessage could be:
1) you have html, empty lines or spaces before "<?php" in your file.
2) you have included another script that echoes already some header or 
content.

Your lines present a simplified kind of the base-code that is created 
automatically by the kickstarter for new extensions. I don't know why 
you changed it to that simplified version but apart from the included 
class getParentElement.php you have nothing inside your code that could 
be responsable for that fault.

Perhaps you debugged something in your foreign class or above your lines 
with echo(), print(), debug(), var_dump(), t3lib_div::debug() or another 
function. Than two headers are created: One at the start of your 
debug-output and another one with $doc->startPage().

Apart from a temporary debug-output (which has to be deactivated for the 
productional version) nothing has to be echoed before $doc->startPage 
and after $doc->endPage(). In your lines you only have one output 
including the content of these functions - that's usual and OK too.

Best Regards
David