Solved

Use a Class's Method as the callback function for ob_start()

Posted on 2008-10-14
4
1,206 Views
Last Modified: 2012-05-05
How can I, or even may I, sue a class's method as the call back function for ob_start()?

I tried several ideas and googled, but nothing doing so far.

The output of the attached code returns:
--------------------------------------------------------------------------------------------
Hello World, and hello {testvar}
Goodbye World, and goodbye {testvar}
Hello World, and hello Beautiful
Goodbye World, and goodbye Ugly
--------------------------------------------------------------------------------------------

When I trying to get this result:
--------------------------------------------------------------------------------------------
Hello World, and hello Beautiful
Goodbye World, and goodbye Ugly
Hello World, and hello Beautiful
Goodbye World, and goodbye Ugly
--------------------------------------------------------------------------------------------

Thanks for the help!
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" /><title>Buffer Testing</title></head>
 
<body>
<?php
class Testclass {
	public $testvar;
	public $html;
 
	public function Testclass() {
		$this->testvar="unknown";
		$this->html="helloworld.html";
	}
	
	public function displayOutput() {
		include($this->html);
	}
	
	public function adjustOutput($buffer){
		return (str_replace("{testvar}", $testvar, $buffer));
	}
	
}//END class Testclass
 
$ONE= new Testclass();
$TWO= new Testclass();
$ONE->testvar="Beautiful";
$ONE->html="helloworld.html";
$TWO->testvar="Ugly";
$TWO->html="goodbyeworld.html";
 
function cheatOne($buffer){
	return (str_replace("{testvar}", "Beautiful", $buffer));
}
function cheatTwo($buffer){
	return (str_replace("{testvar}", "Ugly", $buffer));
}
 
ob_start();//START MAIN BUFFER
 
  ob_start("$ONE->adjustOutput");//buffer one
    $ONE->displayOutput();
  ob_end_flush();
  
  ob_start("$TWO->adjustOutput");//buffer two
    $TWO->displayOutput();
  ob_end_flush();
 
  ob_start("cheatOne");//CHEATING buffer one
    $ONE->displayOutput();
  ob_end_flush();
  
  ob_start("cheatTwo");//CHEATING buffer two
    $TWO->displayOutput();
  ob_end_flush();
 
ob_end_flush();//OUTPUT THE MAIN BUFFER
 
?>
</body>
</html>

Open in new window

0
Comment
Question by:dban00b
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
  • 2
4 Comments
 
LVL 1

Author Comment

by:dban00b
ID: 22716543
There's a typo in Testclass::adjustOutput()  "$testvar"  should read "$this->testvar" -- no change in the original question though, just didn't want anyone to get hung up on that typo.
0
 
LVL 25

Accepted Solution

by:
Marcus Bointon earned 500 total points
ID: 22719629
This is a common thing. instead of providing the name of the function to call, you pass an array containing the instance and the function name, like this:

ob_start(array($ONE, 'adjustOutput');

Docs are here: http://www.php.net/manual/en/language.pseudo-types.php#language.types.callback
0
 
LVL 25

Expert Comment

by:Marcus Bointon
ID: 22719631
Oops, missed a bracket:

ob_start(array($ONE, 'adjustOutput'));
0
 
LVL 1

Author Comment

by:dban00b
ID: 22722001
Awesome!  Thanks!
0

Featured Post

Enroll in June's Course of the Month

June's Course of the Month is now available! Every 10 seconds, a consumer gets hit with ransomware. Refresh your knowledge of ransomware best practices by enrolling in this month's complimentary course for Premium Members, Team Accounts, and Qualified Experts.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Developers of all skill levels should learn to use current best practices when developing websites. However many developers, new and old, fall into the trap of using deprecated features because this is what so many tutorials and books tell them to u…
Since pre-biblical times, humans have sought ways to keep secrets, and share the secrets selectively.  This article explores the ways PHP can be used to hide and encrypt information.
The viewer will learn how to dynamically set the form action using jQuery.
The viewer will learn how to look for a specific file type in a local or remote server directory using PHP.

696 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question