Validation expressions

Validation is done at runtime to ensure that documents follow certain constraints.

Validation constraints are implicitly specified in the definition of a structure: the data type, number of occurrences, and element length for example. They can also be specified either in the structure or map using expressions in the Validate tab for each map element.

Validation expressions require a Boolean value. If the value is true, the element is considered valid. If false, a validation report is generated. The validation report is generic, it only indicates that the validation of the element failed and gives the location of the failure.