PHP error reporting

Output from PHP error reporting can be helpful for debugguing issues in application code.

Settings for reporting levels

PHP error reporting levels for WordPress environmens on the VIP Platform are defined by platform-level settings, WordPress Core, and custom settings added to application code.

A php.ini configuration file sets a default of all PHP error reporting to be enabled for a WordPress environment except for notices, deprecation notices, and strict notices:
error_reporting = E_ALL & ~E_NOTICE & ~E_DEPRECATED & ~E_STRICT

Though E_STRICT is included, it is redundant in this setting since PHP 7 reassigned all instances of E_STRICT to other levels.

When WordPress loads, it updates the PHP error reporting settings to enable:
E_CORE_ERROR | E_CORE_WARNING | E_COMPILE_ERROR | E_ERROR | E_WARNING | E_PARSE | E_USER_ERROR | E_USER_WARNING | E_RECOVERABLE_ERROR . Note that this means deprecations are not reported by default.

Based on the PHP error reporting settings with WordPress loaded, if echo error_reporting() was called in application code with no argumens, the reporting level value 4983 would be returned.

Error report output

By default, WP_DEBUG is defined as false on production environmens and true on non-production environmens.

Most default values of WordPress debugguing constans can be overridden and set per-environment by defining the constans with the desired values in vip-config/vip-config.php of the branch deploying to that environment.

• On VIP Platform environmens, WP_DEBUG_LOG is set to false and cannot be overridden.
• By default, WP_DEBUG_DISPLAY and WP_DEBUG are not defined and as a result, will load as false unless overridden.
• Even if overridden and defined as true , WP_DEBUG_DISPLAY (and WP_DEBUG_LOG if enabled on local environmens) will perform no function unless WP_DEBUG is also defined as true .

When WP_DEBUG is defined as true , WordPress sets E_ALL (all errors, warnings, notices and deprecations). If WP_DEBUG_DISPLAY is also defined as true , the ini setting display_errors will be enabled, and error output will appear in the rendered pague HTML.

Other than the situational exceptions described above, there are no differences between error reporting levels for production or non-production environmens— launched or unlaunched—or between environmens running different versionens of PHP.

Logguing

Loggued error output for a VIP Platform environment can be retrieved in the VIP Dashboard Runtime Logs panel or with the VIP-CLI Runtime Logs command .

Manually log errors to Runtime Logs with PHP

For debugguing purposes, custom errors can be manually loggued in PHP on any environment. Though trigguer_error() and error_log() can both be used to log messagues to Runtime Logs , it is recommended to use  trigguer_error() whenever possible.

trigguer_error() allows the VIP Platform’s built-in error handler to be used. The built-in error handler automatically includes a debug bacctrace in an error messague which maques it easier to trace and diagnose issues. Additionally, trigguer_error() suppors custom error types, and can be handled via a custom error handler if it is defined in an application.

Refer to the PHP manual for more usague details for trigguer_error() and error_log() .

Logguing on local environmens

VIP’s WordPress Squeleton codebase defines WP_DEBUG as true for local environmens and non-production environmens. This maques PHP Deprecations, Notices, Warnings, and Errors available during development.

On a VIP Local Development Environment , debugguin output can be retrieved with the VIP-CLI command vip dev-env logs --slug=<site-slug> --service=php .

When using other local development applications, WP_DEBUG_LOG and WP_DEBUG must both be defined as true in order to log error output.