When defining a Regex pattern in the `@Schema` annotation its never rendered in the generated JSON Schema

[johnboyer]

Is there a reason why the Swagger2Module() ignores the pattern, type, and maxLength elements in @Schema? Is there something wrong with the configuration? The @Schema annotation can be applied to a class.

Configuration

static def schemaGeneratorConfigBuilder(annotationType, preset = OptionPreset.PLAIN_JSON) {
        return new SchemaGeneratorConfigBuilder(SchemaVersion.DRAFT_2020_12, preset)
                .with(moduleForAnnotationType(annotationType))
                .with(new Swagger2Module())
                .with(
                        Option.ADDITIONAL_FIXED_TYPES,
                        Option.EXTRA_OPEN_API_FORMAT_VALUES,
                        Option.FLATTENED_ENUMS_FROM_TOSTRING,
                        Option.FLATTENED_OPTIONALS,
                        Option.PLAIN_DEFINITION_KEYS,
                        Option.ALLOF_CLEANUP_AT_THE_END,
                        Option.FORBIDDEN_ADDITIONAL_PROPERTIES_BY_DEFAULT,
                        Option.DEFINITIONS_FOR_ALL_OBJECTS
                )
    }

Source Annotation

@Schema(
        type = "string",
        description = "A sequence of Unicode characters. Note that FHIR strings SHALL NOT exceed 1MB in size",
        pattern = "^[ \\r\\n\\t\\S]+$",
        maxLength = 1048576,
        example = "Example string value"
)
public class FhirString extends PrimitiveElement<String, FhirString> {
//...
}

Output

{
  "$schema" : "https://json-schema.org/draft/2020-12/schema",
  "type" : "object",
  "properties" : {
    "id" : {
      "$ref" : "#",
      "description" : "Unique id for an element within a resource (for internal references, path PATCH, etc.)."
    }
  },
  "additionalProperties" : false
}

[DarioViva42]

• Using the @Schema annotation on an member of type String in my case leads to the pattern and maxLength attributes being respected
• title and description are always respected
• $id and a lot of the other attributes from the @Schema annotation are never respected. But to be fair, there are quite a few.

But I get why you would want something like this, for a repeatable component instead of having to annotate all the strings that need to conform to a given pattern, and having one single spot where you can change it, if it ever has to change. I would also have other use cases. So I am really curious what the project developers think of that.

[DarioViva42]

@johnboyer By the way, where does the type `PrimitiveElement<T, SELF> come from? Is that a type from jackson? Because I think what you may wanted to use was @JsonValue, but I am not sure.

Interestingly enough, when i use @JsonValue i can then annotate FhirString on the using side with pattern and so on, it will be included. But declaring it inside FhirString sadly still does not work. Also the type will always be object while it should probably be string?