A starting idea: suppose we had a DatabaseAction object with instance variables query, success, fail, and message. Suppose when it was created, it sent itself the message execute(). Suppose that object encapsulated everything. The code, in Smalltalk, might look like this:
DatabaseAction
query: queryThatCouldFail
success: updateThatCouldFail
failure: anotherThingThatCouldFail
message: tellUserItDidn'tWork
Naturally there would be default forms such as
DatabaseAction query: queryThatCouldFail
Could a system built around DatabaseAction be simpler, more clear, faster to write, more reliable than hand-coding conditional OR try/catch code? Nah, probably not.
Hey, pull the execute call out of construction, make it a composite and implement transactions. Why wouldn't it work? -- MichaelFeathers
It would. But don't tell the C++ guys.