{
    "$schema": "http://json-schema.org/draft-07/schema#",
    "definitions": {
        "evalObject": {
            "type": "object",
            "properties": {
                "eval": {
                    "type": "string",
                    "description": "js code which must return same schema as value if directly defined"
                }
            }
        },

        "i18nString": {
            "oneOf": [
                {
                    "type": "object",
                    "patternProperties": {
                        "^[a-z]$": {
                            "type": "string"
                        }
                    }
                },
                {
                    "type": "string"
                }
            ]
        },
        "evalExpressions": {
            "oneOf": [
                {
                    "type": "object",
                    "additionalProperties": true,
                    "properties": {
                        "twig": {
                            "type": "string",
                            "description": "twig template"
                        },
                        "projection": {
                            "type": "string",
                            "description": "query projection to use"
                        }
                    },
                    "required": ["twig"]
                },
                {
                    "type": "object",
                    "additionalProperties": true,
                    "properties": {
                        "eval": {
                            "type": "string",
                            "description": "javascript code"
                        },
                        "projection": {
                            "type": "string",
                            "description": "query projection to use"
                        }
                    },
                    "required": ["eval"]
                }
            ]
        },
        "fieldSource": {
            "oneOf": [
                {
                    "$ref": "#/definitions/fieldPath"
                },
                {
                    "type": "object",
                    "properties": {
                        "source": {
                            "$ref": "#/definitions/fieldPath"
                        }
                    }
                }
            ]
        },
        "fieldPath": {
            "type": "string",
            "description": "field, sub fields separated with dot (.)",
            "pattern": "^[a-zA-Z0-9_]+(\\.[a-zA-Z0-9_]+)*$"
        }
    }
}