Bug #76571 [Nab]: str_replace fails to replace string in special output buffered environment

Edit report at https://bugs.php.net/bug.php?id=76571&edit=1 ID: 76571 Updated by: requinix@php.net Reported by: roland at nextendweb dot com Summary: str_replace fails to replace string in special output buffered environment Status: Not a bug Type: Bug Package: Output Control PHP Version: 7.2.7 Block user comment: N Private report: N New Comment: FINAL is the one. Previous Comments: ------------------------------------------------------------------------ [2018-07-03 09:05:59] roland at nextendweb dot com Well, it makes sense. So I should use the output callback phase parameter to check. Could you tell me which is the phase which runs only once when the output buffer closed completely? class a { private static $bug = 'World'; public static function parse_output($buffer, $phase) { if ( $phase & PHP_OUTPUT_HANDLER_FINAL ){ $buffer = str_replace('there', self::$bug, $buffer); self::$bug = 'What?'; } return $buffer; } } ------------------------------------------------------------------------ [2018-07-03 08:41:26] requinix@php.net http://php.net/manual/en/function.ob-start.php > The [output_callback] function will be called when the output buffer is flushed (sent) or > cleaned (with > ob_flush(), ob_clean() or similar function) or when the output buffer is flushed to the browser > at the end of the > request. 1. When you echo "Hello there", the callback is *not invoked immediately* 2. ob_get_contents returns "Hello there" back 3. ob_clean sends "Hello there" to the callback, which replaces using "World", but the result is discarded 4. You echo the original "Hello there" again 5. ob_end_flush sends the new "Hello there" to the callback, which replaces using "What?", and the result is sent Is there a reasonable use case behind this problem? Because otherwise what you should be doing is simply ob_start('a::parse_output'); echo "Hello there"; ob_end_flush(); ------------------------------------------------------------------------ [2018-07-03 07:22:46] roland at nextendweb dot com Description: ------------ http://sandbox.onlinephpfunctions.com/code/08eee50202cb2e8ce5b6e849aacb7c5bf37de4ba Test script: --------------- <?php class a { private static $bug = 'World'; public static function parse_output($buffer) { $buffer = str_replace('there', self::$bug, $buffer); self::$bug = 'What?'; return $buffer; } } ob_start('a::parse_output'); echo "Hello there"; $content = ob_get_contents(); ob_clean(); echo $content; ob_end_flush(); Expected result: ---------------- Hello World Actual result: -------------- Hello What? ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=76571&edit=1