[Resolved] Photo gallery - photo image error **Warning: Cannot modify header information**

[spoons84]

Hi guys,

Ive started creating my own photo gallery

Got a table which hold the gallery folder name, description and a photo (to be shown as the folders front cover)

Ive coded to show all the folders in the table, but having problems showing the photos.....

Ive previously used the following to show a single photo from the db:

		// Connect to the database
		mysql_connect("localhost", "root", "") or die("Could not connect : " . mysql_error());
		mysql_select_db("advertising") or die("Could not select database");

	//Select the image data from the website table
	$query = "select bin_data, image_type from websites where ID=$id";
    $result = @MYSQL_QUERY($query);

    $data = @MYSQL_RESULT($result,0,"bin_data");
	$type = @MYSQL_RESULT($result,0,"image_type");

	//Determine the type of file
	Header( "Content-type: $type");

	//Echo the image file
	echo $data;
}

To use it for all data Ive put:

			//Create a new row for each match
			while($row=mysql_fetch_array($q)) {

			echo('<tr>');
			echo("<td COLSPAN=3 ALIGN=center><A HREF='folder.php'>");

			if ($row["bin_data"]) {

			//Select the image data from the website table
			$query = "select bin_data, image_type from gallery_folder where galleryID=".$row['galleryID']."";
		    $result = @MYSQL_QUERY($query);

			$data = @MYSQL_RESULT($result,0,"bin_data");
			$type = @MYSQL_RESULT($result,0,"image_type");
			//Determine the type of file
			Header( "Content-type: $type");

			echo $data;

		}
			echo ("</A></td>");	

			echo("<td COLSPAN=3 ALIGN=center><I><DIV CLASS=mainText>". $row["title"] ."</DIV></I></td>");	
);	

But everytime I get the error:

Warning: Cannot modify header information - headers already sent by (output started at C:\apachefriends\xampp\htdocs\travel site\gallery.php:160) in C:\apachefriends\xampp\htdocs\travel site\gallery.php on line 199

Line 160 is: echo '<DIV CLASS="mainText">The current folders:</DIV>';

Line 199 is: Header( "Content-type: $type");

So obv doesnt like the Header part, which im not sure whats wrong....am using a session code to maintain the user id whilst they are on the site which is the only thing i can think:

		// start the session
		session_start();
		header("Cache-control: private"); //IE 6 Fix

Any help would be great!

Cheers,
Spoons

[devinemke]

read up on headers

[LoganK]

The real problem is that you're trying to modify the headers after they've been sent. Everytime HTML is sent to the browser, whether it be straight HTML or outputted by an echo() statement in PHP, headers are sent defining and identifying the type of content. Since you send HTML code to make a table, headers are already sent and they cannot be modified. Usually, to fix this all you need to do is move the header() statement to before any echo statements, but in this case it's more complex, because you're outputting HTML code but changing the document type to an image of some sort. Basically, if you didn't understand that, is that you're telling the browser "here comes image data", but then you give it HTML data. What I'd do in your case is for the "show all images at once code", just call the "show one image" code repeatedly, once for each image to be shown. Your best option is to put the image-generating code into a file like image.php and referencing it from within HTML. Like <img src="image.php?id=5">. Then image.php can get the ID, query the database for the image info, and output the image. For the show all images at once, just call the image.php many times:

<img src="image.php?id=1">
<img src="image.php?id=2">
<img src="image.php?id=3">
<img src="image.php?id=4">
...
<img src="image.php?id=99">

Hope this helps!

[Weedpacket]

From the very top thread in this forum
2. Headers Already Sent...

[LoganK]

Didn't realize it...spoons, take a look at Weedpacket's link; it'll give you all you need to know.

[spoons84]

Cheers guys,

Read the headers info and used LoganK's advise to figure it out.

Managed to put the query for finding the image in one file then using the include() function in another to parse data.

Thanks again,

Spoons