Failing properly.
WHAT PHP PRODUCES
Errors, at several levels of severity Exceptions, which can be caught
WHAT TO SET IN DEVELOPMENT
Display errors on, and report everything.
WHAT TO SET IN PRODUCTION
Display errors off, and log everything.
WHY OFF
Errors displayed to visitors reveal paths, versions and sometimes credentials.
WHAT TO DO INSTEAD
Log them, and show a generic message.
WHAT TO CATCH
Specific exceptions you can actually handle.
WHAT NOT TO CATCH
Everything, indiscriminately.
WHY
It hides bugs you would want to know about.
WHAT TO DO WHEN YOU CANNOT HANDLE SOMETHING
Let it propagate, or throw something more meaningful.
WHAT TO NEVER DO
Suppress errors with the suppression operator.
WHY
It hides the problem without solving it, and makes diagnosis impossible.
WHAT TO ALWAYS CLEAN UP
Files, connections and locks, whether or not an error occurred.
WHAT TO LOG
What failed, with what input, and when.
