Fail mediation primitive

Use the Fail mediation primitive to stop a mediation flow, and generate an exception.

Introduction

You can use the Fail mediation primitive to halt a mediation flow and raise an exception at a point you choose in the flow. You can also add information about a failure.

The Fail mediation primitive has one input terminal (in). The input terminal is wired to accept a message that triggers a FailFlowException. A FailFlowException is a specific runtime exception that causes the flow instance to fail. You can wire the output terminal of another mediation primitive to the in terminal of a Fail mediation primitive, to cause a FailFlowException.

Usage

You can use the Fail mediation primitive to define your own error conditions, based on the business logic of the flow.

You can use the Error message property to provide an additional error message that is specific to your business logic or domain. The Error message you create is added to the automatically generated exception.

You can use the Root and Error message properties to specify that information from the service message object (SMO) is also included in the Error message, so that the automatically generated exception contains dynamic information about the state of the SMO. The default value for the Error message property is {0}, {1}, {2}, {3}, {4}, {5} meaning that:

{0} would be substituted with the Time Stamp value
{1} would be substituted with the SMO Message ID value
{2} would be substituted with the Mediation Name value
{3} would be substituted with the Module Name value
{4} would be substituted with the SMO part defined by the Root property XPath. By default this is /context/failInfo
{5} would be substituted with the SMO Version value

A generated FailFlowException for the default Error message and Root would therefore contain information such as:

'29/04/09 15:11, 9A85B1D2-0119-4000-E000-13E4091443BC, Fail1, MyModule, <failInfo>...</failInfo>, 6'

You can use the Fail mediation primitive to roll back a global transaction under certain conditions. For example, if you wire an output terminal of a Message Filter mediation primitive to a Fail mediation primitive, the transaction is rolled back if the filter condition occurs.