Discussion
There are three main kinds of errors that can arise. Many possible situations can crop up within PHP code that count as errors, such as an attempt to use a method on a variable that turns out not to be an object, or is an object but does not implement the specified method. The database will sometimes report errors, such as an attempt to retrieve information from a non-existent table, or to ask for a field that has not been defined for a table. And the logic of applications can often lead to situations that can only be described as errors. What resources do we have to handle these error situations?
PHP error handling
If nothing else is done, PHP has its own error handler. But developers are free to build their own handlers. So that is the first item on our to do list. Consistently with our generally object oriented approach, the natural thing to do is to build an error recording class, and then to tell PHP that one of its methods is to be called whenever PHP detects an error. Once...
