Requiredhasx

Requiredhasx is a term used in data validation and schema design to describe a combined constraint: an object must include a field named x, and the value associated with that field (if provided by the schema) must satisfy optional predicates. The phrase blends the notions of a required field with a “has” condition on the field’s presence and value. Because requiredhasx is not part of a single standardized specification, its exact meaning and syntax vary across implementations, but the core idea remains consistent: ensure a specific field exists and optionally enforce quality or type constraints on its value.

In practice, requiredhasx is discussed as a way to express cross-field and value-dependent rules that go beyond simple required/not-required checks. It is useful for API contracts, data models, and form validation where the presence of one field implies or necessitates certain properties of that field or related fields. For example, a user profile schema might use requiredhasx to require that an email field is present and non-empty, and that the email value conforms to a pattern. In other contexts, the rule could enforce that if a field x is present, it must hold a value of a certain type or satisfy a predicate such as non-null, non-empty, or within a specified range.

Implementation typically involves custom validators or constraint languages and is not yet standardized. Critics point to potential ambiguity in semantics and interoperability across systems. For most projects, explicit, well-documented validators or conditional schemas can achieve similar results with clearer portability.

See also: required, cross-field validation, constraint languages, data validation.