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Changes between Initial Version and Version 1 of Ticket #64108


Ignore:
Timestamp:
10/16/2025 07:26:37 PM (10 months ago)
Author:
westonruter
Comment:

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  • Ticket #64108 – Description

    initial v1  
    1616
    1717We should better handle errors triggered during a user output handler. We capture with an error handler and then when `display_errors` is on we can append the errors as HTML to the response.
     18
     19Example plugin which emits errors before and during the output buffer callback:
     20
     21{{{#!php
     22<?php
     23/**
     24 * Plugin Name: Emit Errors Before and During Output Buffer Callback
     25 * Requires at least: 6.9-alpha
     26 */
     27
     28namespace EmitErrorsBeforeAndDuringOutputBufferCallback;
     29
     30function emit_notices() {
     31        _doing_it_wrong( __FUNCTION__, '✅ You are doing it wrong at ' . current_action(), '0.0.0' );
     32        wp_trigger_error( __FUNCTION__, '✅ Notice ' . current_action(), E_USER_NOTICE );
     33        wp_trigger_error( __FUNCTION__, '✅ Deprecated ' . current_action(), E_USER_DEPRECATED );
     34        wp_trigger_error( __FUNCTION__, '✅ Warning ' . current_action(), E_USER_WARNING );
     35}
     36
     37add_action( 'wp_before_include_template', __NAMESPACE__ . '\emit_notices' );
     38
     39add_filter(
     40        'wp_template_enhancement_output_buffer',
     41        static function ( $buffer ) {
     42                emit_notices();
     43                return $buffer;
     44        }
     45);
     46
     47}}}
     48
     49With PHP 8.5 active, this results in the following errors being printed before the HTML document is served:
     50
     51* Deprecated: ob_end_flush(): Producing output from user output handler wp_finalize_template_enhancement_output_buffer is deprecated in /var/www/src/wp-includes/functions.php on line 5481
     52* Notice: Function EmitErrorsBeforeAndDuringOutputBufferCallback\emit_notices was called incorrectly. ✅ You are doing it wrong at wp_before_include_template Please see Debugging in WordPress for more information. (This message was added in version 0.0.0.) in /var/www/src/wp-includes/functions.php on line 6131
     53* Notice: EmitErrorsBeforeAndDuringOutputBufferCallback\emit_notices(): ✅ Notice wp_before_include_template in /var/www/src/wp-includes/functions.php on line 6131
     54* Deprecated: EmitErrorsBeforeAndDuringOutputBufferCallback\emit_notices(): ✅ Deprecated wp_before_include_template in /var/www/src/wp-includes/functions.php on line 6131
     55* Warning: EmitErrorsBeforeAndDuringOutputBufferCallback\emit_notices(): ✅ Warning wp_before_include_template in /var/www/src/wp-includes/functions.php on line 6131
     56
     57Notice only the four errors printed during the `wp_before_include_template` action are printed. None of the errors during the `wp_template_enhancement_output_buffer` filter are printed. They all appear in the error log, however:
     58
     59{{{
     60[16-Oct-2025 19:23:00 UTC] PHP Notice:  Function EmitErrorsBeforeAndDuringOutputBufferCallback\emit_notices was called <strong>incorrectly</strong>. ✅ You are doing it wrong at wp_before_include_template Please see <a href="https://developer.wordpress.org/advanced-administration/debug/debug-wordpress/">Debugging in WordPress</a> for more information. (This message was added in version 0.0.0.) in /var/www/src/wp-includes/functions.php on line 6131
     61[16-Oct-2025 19:23:00 UTC] PHP Notice:  EmitErrorsBeforeAndDuringOutputBufferCallback\emit_notices(): ✅ Notice wp_before_include_template in /var/www/src/wp-includes/functions.php on line 6131
     62[16-Oct-2025 19:23:00 UTC] PHP Deprecated:  EmitErrorsBeforeAndDuringOutputBufferCallback\emit_notices(): ✅ Deprecated wp_before_include_template in /var/www/src/wp-includes/functions.php on line 6131
     63[16-Oct-2025 19:23:00 UTC] PHP Warning:  EmitErrorsBeforeAndDuringOutputBufferCallback\emit_notices(): ✅ Warning wp_before_include_template in /var/www/src/wp-includes/functions.php on line 6131
     64[16-Oct-2025 19:23:00 UTC] PHP Notice:  Function EmitErrorsBeforeAndDuringOutputBufferCallback\emit_notices was called <strong>incorrectly</strong>. ✅ You are doing it wrong at wp_template_enhancement_output_buffer Please see <a href="https://developer.wordpress.org/advanced-administration/debug/debug-wordpress/">Debugging in WordPress</a> for more information. (This message was added in version 0.0.0.) in /var/www/src/wp-includes/functions.php on line 6131
     65[16-Oct-2025 19:23:00 UTC] PHP Notice:  EmitErrorsBeforeAndDuringOutputBufferCallback\emit_notices(): ✅ Notice wp_template_enhancement_output_buffer in /var/www/src/wp-includes/functions.php on line 6131
     66[16-Oct-2025 19:23:00 UTC] PHP Deprecated:  EmitErrorsBeforeAndDuringOutputBufferCallback\emit_notices(): ✅ Deprecated wp_template_enhancement_output_buffer in /var/www/src/wp-includes/functions.php on line 6131
     67[16-Oct-2025 19:23:00 UTC] PHP Warning:  EmitErrorsBeforeAndDuringOutputBufferCallback\emit_notices(): ✅ Warning wp_template_enhancement_output_buffer in /var/www/src/wp-includes/functions.php on line 6131
     68[16-Oct-2025 19:23:00 UTC] PHP Deprecated:  ob_end_flush(): Producing output from user output handler wp_finalize_template_enhancement_output_buffer is deprecated in /var/www/src/wp-includes/functions.php on line 5481
     69[16-Oct-2025 19:23:00 UTC] PHP Deprecated:  ob_end_flush(): Producing output from user output handler {closure:od_buffer_output():54} is deprecated in /var/www/src/wp-includes/functions.php on line 548
     70}}}
     71
     72In PHP 8.4, the deprecation notice for `ob_end_flush()` does not appear, and neither to any of the errors emitted during the output buffer callback.