Graceful errors for failing plugins in ACP

[dvz]

Display user-friendly error messages in the ACP's Plugins module when plugins fail to load (including names of the problematic extensions).

While printed PHP errors may indicate specific plugins, on installations/servers with suppressed error output a blank or half-blank page is presented. The Plugins management page is usually most prone to errors, as all plugin files are loaded, including not-yet-activated ones:

mybb/admin/modules/config/plugins.php

Line 526 in 50d3006

require_once MYBB_ROOT."inc/plugins/".$plugin_file;

This may be addressed through a client-side watchdog script included early, and executed on (technical) page load, which inserts error messages according to last-encountered tags in page source (e.g. <!-- plugin-include-before "hello" --> without <!-- plugin-include-after "hello" --> would indicate a failure in the hello plugin).

Future improvements may include:

• server-side requests to self to check for successful inclusion of plugin files (the client-side watchdog may redirect to such server-side mode to ultimately render the full page correctly)
• links/advice for "safe mode" plugin management
  Restrict loading plugins files during NO_PLUGINS #4805