How do I capture PHP output into a variable?

Question

I'm generating a ton of XML that is to be passed to an API as a post variable when a user click on a form button. I also want to be able to show the user the XML before hand.

The code is sorta like the following in structure:

<?php
    $lots of = "php";
?>

<xml>
    <morexml>

<?php
    while(){
?>
    <somegeneratedxml>
<?php } ?>

<lastofthexml>

<?php ?>

<html>
    <pre>
      The XML for the user to preview
    </pre>

    <form>
        <input id="xml" value="theXMLagain" />
    </form>
</html>

My XML is being generated with a few while loops and stuff. It then needs to be shown in the two places (the preview and the form value).

My question is. How do I capture the generated XML in a variable or whatever so I only have to generate it once and then just print it out as apposed to generating it inside the preview and then again inside the form value?

moo · Accepted Answer · 2018-10-02 22:32:46Z

131

<?php ob_start(); ?>
<xml/>
<?php $xml = ob_get_clean(); ?>
<input value="<?php echo $xml ?>" />͏͏͏͏͏͏

edited Oct 2, 2018 at 22:32

user7090116

answered Oct 5, 2008 at 1:33

moo

7,8379 gold badges46 silver badges40 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

lejahmie Over a year ago

@Jleagle $xml = ob_get_clean() will return output buffert and clean output. It essentially executes both ob_get_contents() and ob_end_clean()

kajacx Over a year ago

Don't forget to use htmlentities($xml), or else your site will break if the xml has " in it.

Community · Accepted Answer · 2023-11-17 20:38:18Z

55

Put this at your start:

ob_start();

And to get the buffer back:

$value = ob_get_contents();
ob_end_clean();

See https://www.php.net/manual/en/ref.outcontrol.php and the individual functions for more information.

edited Nov 17, 2023 at 20:38

CommunityBot

11 silver badge

answered Oct 5, 2008 at 1:31

Robert K

30.4k12 gold badges64 silver badges79 bronze badges

Comments

Community · Accepted Answer · 2023-11-17 20:42:18Z

11

It sounds like you want PHP Output Buffering

ob_start(); 
// make your XML file

$out1 = ob_get_contents();
//$out1 now contains your XML

Note that output buffering stops the output from being sent, until you "flush" it. See the Documentation for more info.

edited Nov 17, 2023 at 20:42

CommunityBot

11 silver badge

answered Oct 5, 2008 at 1:33

maxsilver

4,6144 gold badges30 silver badges24 bronze badges

Comments

David Wolf · Accepted Answer · 2022-02-24 20:40:17Z

3

When using frequently, a little helper could be helpful:

class Helper
{
    /**
     * Capture output of a function with arguments and return it as a string.
     */
    public static function captureOutput(callable $callback, ...$args): string
    {
        ob_start();
        $callback(...$args);
        $output = ob_get_contents();
        ob_end_clean();
        return $output;
    }
}

edited Feb 24, 2022 at 20:40

answered Feb 24, 2022 at 20:33

David Wolf

1,7382 gold badges14 silver badges21 bronze badges

Comments

mattoc · Accepted Answer · 2008-10-06 01:23:56Z

2

You could try this:

<?php
$string = <<<XMLDoc
<?xml version='1.0'?>
<doc>
  <title>XML Document</title>
  <lotsofxml/>
  <fruits>
XMLDoc;

$fruits = array('apple', 'banana', 'orange');

foreach($fruits as $fruit) {
  $string .= "\n    <fruit>".$fruit."</fruit>";
}

$string .= "\n  </fruits>
</doc>";
?>
<html>
<!-- Show XML as HTML with entities; saves having to view source -->
<pre><?=str_replace("<", "&lt;", str_replace(">", "&gt;", $string))?></pre>
<textarea rows="8" cols="50"><?=$string?></textarea>
</html>

answered Oct 6, 2008 at 1:23

mattoc

7125 silver badges6 bronze badges

Collectives™ on Stack Overflow

How do I capture PHP output into a variable?

5 Answers 5

2 Comments

Comments

Comments

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

2 Comments

Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related