Displaying images with php

[BigMike]

I'm trying to create and display an image using php. The code I am using is shown below.

<?php
include("dbAccess.php");
$Text=getTextForID($id);

if ($Text==""){$Test="Boo";}
$png = ImageCreate(200, 80);
$bg = ImageColorAllocate($png, 255, 255, 255);
$tx = ImageColorAllocate($png, 0, 0, 0);
ImageFilledRectangle($png, 0, 0, 200, 80, $bg);
ImageString($png, 5, 45, 25, $Text, $tx);

header("content-type: image/png");

ImagePng($png);
imagedestroy ($png);

?>

It works if the first two lines are removed (getTextForID is a function in dbAccess that returns a string) as in, it displays an image, but if the first two lines are there it falls over saying:

"Warning: Cannot add header information - headers already sent by (output started at /home/xxx/public_html/list/dbAccess.php:157) in /home/xxx/public_html/list/image.php on line 13"

dbAccess contains only functions. ie there is no code executed outside of a function call. I need to get data from the db, and don't wish to move the db connection and access code out of the dbAccess file.

What is the trick on this one ?

Thanks,

Mike

[Rohan_Hill]

Hi, what this is telling you is that on line 13 of dbAccess.php, which is presumably part of the function getTextForID(), some output was sent to the user. If output has already been sent to the user, PHP cannot sent the user an image. Does that help?

[barand]

It certainly sounds as though something in those first 2 lines is sending output to the browser, even if it's just a blank line.

[BigMike]

Originally posted by Rohan Hill
Hi, what this is telling you is that on line 13 of dbAccess.php, which is presumably part of the function getTextForID(), some output was sent to the user. If output has already been sent to the user, PHP cannot sent the user an image. Does that help?

Yeah kind of. Line 13 of the calling file was where the header line is - line 157 is the end of dbAccess - and this is the clue, the output that had stated was blank lines at the end of dbAccess.

Cheers,

Mike

[BigMike]

Originally posted by barand
It certainly sounds as though something in those first 2 lines is sending output to the browser, even if it's just a blank line.

Barand,

this was it - I had blank lines at the end of the dbAccess file. I didn't realise php was so fussy.

I'm just pleased my code was right 😃

Thanks for the suggestion,

Regards,

Mike