GD JSON Schema

A addon for Godot to validate objects or dictionaries with JSON Schemas.

• Supporting a minimal subset of JSONSchema tags - see the tag_validation_funcs list.
• Can validate Objects or Dictionaries
• Implemented in GDScript.

How to Use

1. Make a schema

var test_schema = {
	"type": "object",
	"properties": {
		"name": { "type": "string" },
		"age": { "type": "integer" }
	},
	"not": {
		"properties": {
			"name": { "pattern": "^J.*" } # Name should NOT start with "J"
		}
	}
}

2. Test some objects

var valid_obj = {"name": "Alice", "age": 30}

var invalid_obj = {"name": "John", "age": 25}

print('\nTesting invalid instance:')
var issues = JSONSchema.validate_schema(invalid_obj, test_schema)
for issue in issues:
  print('\t- ' + issue)
	
print('\nTesting valid instance:')
issues = JSONSchema.validate_schema(valid_obj, test_schema)
for issue in issues:
  print('\t- ' + issue)

Output:

Testing invalid instance:
	- not: instance violates "not" schema (should be invalid).

Testing valid instance:

How to Add More Tags

1. Create a new validation function following this format:

func _validate_some_other_tag(instance, some_other_tag, parent:Dictionary = {}) -> Array[String]:
	# TODO: fill in your validation logic here
	return []

2. Add your validation function to the tag_validation_funcs dictionary:

static var tag_validation_funcs = {
	"type": _validate_type,
	"properties": _validate_properties,
	<..>
	'additionalProperties': _validate_additional_properties,
	'not': _validate_not,
	'someOtherTag':_validate_some_other_tag
}

3. You're done - don't forget to test it.

Other Notes

• AI wrote and reviewed the regexes used for format validation, they passed 1 test each but you might consider tightening them up if they're crucial to your use case. The AI was instructed to err on the permissive side.
• I wrote this because I need it, which is why it only features the tags I need right now, if you add more tags please submit a pull request and I'll merge them in.