In our second installment of the 2020 Groovy Week, we are going to cover the topic of adding messages to the transformation log as well as showing how to handle situations where an error needs to be raised, e.g. due to incomplete or unexpected source data. Like the previous post, note that this article assumes you have working knowledge of hale\u00bbstudio and know the terminology.<\/p>\n
When using a Groovy script for a specific mapping task, you often need to add checks that verify that the incoming source data can actually be transformed correctly. In cases where the transformation cannot proceed (e.g. because of missing or erroneous source data), the cause needs to be reported. To achieve that, you can add error<\/em>, warning<\/em> and informational<\/em> messages to the transformation log as well as throw exceptions to signal a critical error.<\/p>\n The following script is part of an alignment that transforms road data to the INSPIRE Transport Network Roads schema. It first defines two conditions hatFahrbahnachse<\/code> and hatStrassenachse<\/code> based on if the source instance contains a link to a AX_Fahrbahnachse<\/code> or AX_Strassenachse<\/code> source instance. If neither condition is met, the transformation cannot proceed. An error message is added to the transformation log and a NoResultException<\/code> is thrown to indicate that the script did not create a result in this case, which is a critical error.<\/p>\n