Error Levels
Pipeline components return one of the following values:
1 = OPPERRORLEV_SUCCESS
2 = OPPERRORLEV_WARN
3 = OPPERRORLEV_FAIL
The pipeline keeps track of the highest error value returned by a previously executed component in the pipeline. Attached to each stage in the pipeline is an attribute that indicates the maximum error level the component will tolerate. If the current error level is less than or equal to the maximum error level for this stage, the components can run the IPipelineComponent::Execute method.
Error levels are checked upon entrance to stages to improve the user experience. For example, a user has completed the shipping stage, the tax stage, and the payment stage, and has entered incorrect information, causing level 3 errors in any or all of these stages. Instead of prompting the user with a shopper warning after each stage, the user can be presented with just one error before the processing of the credit card in the accept stage. This is because, when the level 3 errors are encountered by the accept stage, which has a maximum error level of 2, it prompts the user with a shopper warning indicating all the errors at one time.