Can we produce dependentRequired or other conditions somehow?

[HenrikPublic]

Is there any way we can annotate a class in some magic way to represent conditions and have the generator produce such schemas?

Look at the examples here: https://json-schema.org/understanding-json-schema/reference/conditionals.html
How would we describe this in a way that would make the generator produce the correct conditions?

[CarstenWickner]

Hi @HenrikPublic,

The short answer is: No, no magic annotation (that I know of) would fully cover the nearly endless possibilities there.
The main challenge is the if/then/else subschemas, which often don't correspond to a Java type, i.e., need to be "hand-crafted". The same goes for dependentSchemas.

If you have a concrete example, I may be able to provide you with a concrete suggestion for that use case.

[HenrikPublic]

Thought soo, unfortunately 😊

I was dreaming about something like

@NotNull Value required;
Value optional;
@RequiredIf("optional") OtherValue dependentRequired;

For if-then-else, I am not sure how I envisioned this. Perhaps with a list of annotations:

@NotNull Country country;
@IfThenElse {
  @MagicCheck("country",Country.US
  @Pattern(regexp = "some-pattern"),
  @Pattern(regexp = "some-other-pattern)
} PostalCode postalCode

The allOf and anyOf probably gets even more contrived...

I just hoped someone already saw that need and had thought of a clever solution ;-)

[HenrikPublic]

Examples would be much appreciated!

[CarstenWickner]

I've created an example that looks like this:

    @SchemaCondition(
            ifFulFilled = @SchemaProperty(name = "country", constValue = "US"),
            thenExpect = @SchemaProperty(name = "postalCode", pattern = "^\\d{5}(?:[-\\s]\\d{4})?$"),
            elseExpect = @SchemaProperty(name = "postalCode", pattern = "^[-\\s\\d]+$")
    )
    static class TestType {

        String country;
        String postalCode;
    }

    @Target({ElementType.FIELD, ElementType.METHOD, ElementType.TYPE})
    @Retention(RetentionPolicy.RUNTIME)
    @interface SchemaCondition {
        SchemaProperty ifFulFilled();
        SchemaProperty[] thenExpect() default {};
        SchemaProperty[] elseExpect() default {};
    }

    @Target({ElementType.ANNOTATION_TYPE})
    @Retention(RetentionPolicy.RUNTIME)
    @interface SchemaProperty {
        String name();
        String constValue() default "";
        String pattern() default "";
    }

The full example is here:
https://github.com/victools/jsonschema-generator/blob/main/jsonschema-examples/src/main/java/com/github/victools/jsonschema/examples/IfThenElseExample.java

The generated output would look like this:
https://github.com/victools/jsonschema-generator/blob/main/jsonschema-examples/src/test/resources/com/github/victools/jsonschema/examples/IfThenElseExample-result.json

[HenrikPublic]

That's really helpful! Thanks a lot :-)

[CarstenWickner]

Release v4.30.0 has been published. 🚀

It includes support for the dependentRequired keyword as per the aforementioned PR.