Meaning
Rule-based validation languages permit the assertion of complex constraints on structured data that exceed the capabilities of grammar-based schemas. ISO schematron uses path expressions to navigate an information tree and test for conditions that involve multiple elements or attributes simultaneously. It is an international standard that complements traditional modeling tools like XSD or DTD.
Assertion Logic
Individual rules are written as declarative statements that must evaluate to true. If an iso schematron test fails, the processor returns a specific message defined by the developer. This allows for precise feedback about what is wrong with the data.
Abstract Pattern
Reusable templates allow the same validation logic to be applied to different parts of a document. Using an iso schematron pattern helps maintain consistency when checking similar structures across a large project. It reduces the amount of code needed to enforce business rules.
Business Requirement
Complex constraints often involve relationships that a standard schema cannot express. For instance, an iso schematron rule might verify that the shipping date is always later than the order date. It might also check that the sum of line items matches the total invoice amount.
These types of checks are essential for data integrity in manufacturing and logistics. They prevent errors that would otherwise require manual intervention or cause downstream system failures.