Transactions

CHO uses dry-transactions to organize and perform actions on the various components of the system.

Practices

While dry-transactions has a very general purpose use, we employ some basic principles and practices when we implement them:

• a single "transaction" encompasses multiple operations
• operations can used across different transactions
• operations can be used alone, outside of a transaction, but usually are not
• operations have no opinions or knowledge about the other operations that occur before and after them
• an operation returns either a Success or Failure object
• a Failure is usually returned when an error is rescued, but it doesn't have to be (see the Import::Validate operation)
• a Success is returned when the operation is performed successfully, without any errors
• multiple success and failure paths may exist within a single operation
• a Success can be similar to a guard clause, which passes along the arguments received by the operation to the next operation, without performing any actions (see the File::Save and Import::Work operations)