Condition handling, error handling, and exception handling are all industry terms for programming designed to respond to run-time occurrences that interrupt the usual flow of a software application. Depending on the language, these occurrences can be called conditions, errors, or exceptions. In ABL, condition refers to all possible flow interruptions. Error refers to the most common type of condition. An error occurs when the ABL virtual machine (AVM) fails to successfully execute ABL code. Errors raised by the AVM are called system errors. Error raised programatically are called application errors. In some languages, unrecoverable errors are called exceptions. In ABL, the STOP condition represents unrecoverable errors.
Generally speaking, a condition differs from other run-time events in that it is unexpected and requires a response to restore application flow. In ABL, a condition always invokes a default response provides which is called default error handling. This robust default error handling protects persistent data while also providing branching options to restore application flow. You design your ABL application to accept default error handling, to suppress it, or to replace it with custom error handling.
To be precise, the topic of this manual is condition handling. Since most condition handling in ABL involves the ERROR condition, error handling is a defacto synonym for condition handling and the most frequently used term in the OpenEdge documentation set.
