如何实现基于newPrices数组长度的thresholds属性条件必填？

要实现「当newPrices数组元素数量大于1时，thresholds为必填项」的逻辑，由于Draft-04不支持if/then关键字，我们可以通过allOf结合not/required构建条件约束，具体修改如下：

修改要点 #

1. 调整基础必填规则：将prices.items下的required数组从["newPrices", "thresholds"]改为仅["newPrices"]，因为thresholds不再是全局必填项。
2. 添加条件约束：通过allOf引入额外规则，禁止出现「newPrices长度大于1且未提供thresholds」的非法情况。

修改后的完整Schema #

{
    "$schema": "http://json-schema.org/draft-04/schema#",
    "type": "object",
    "required": [
        "id"
    ],
    "properties": {
        "id": {
            "type": "string",
            "maxLength": 50,
            "minLength": 1,
            "title": "ID",
            "readOnly": true
        },
        "description": {
            "type": "string",
            "nullable": true,
            "title": "Description"
        },
        "allItems": {
            "type": "array",
            "title": "All Items",
            "items": {
                "required": [
                    "prices"
                ],
                "type": "object",
                "properties": {
                    "prices": {
                        "type": "array",
                        "maxItems": 8,
                        "title": "Test Prices",
                        "items": {
                            "required": [
                                "newPrices"
                            ],
                            "type": "object",
                            "properties": {
                                "newPrices": {
                                    "type": "array",
                                    "title": "New Prices",
                                    "maxItems": 4,
                                    "minItems": 1,
                                    "items": {
                                        "type": "number",
                                        "format": "double"
                                    }
                                },
                                "thresholds": {
                                    "type": "array",
                                    "maxItems": 3,
                                    "title": "Thresholds",
                                    "items": {
                                        "type": "integer",
                                        "format": "int32"
                                    }
                                }
                            },
                            "additionalProperties": false,
                            "allOf": [
                                {
                                    "not": {
                                        "allOf": [
                                            {
                                                "properties": {
                                                    "newPrices": {
                                                        "minItems": 2
                                                    }
                                                },
                                                "required": ["newPrices"]
                                            },
                                            {
                                                "not": {
                                                    "required": ["thresholds"]
                                                }
                                            }
                                        ]
                                    }
                                }
                            ]
                        }
                    }
                },
                "additionalProperties": false
            },
            "nullable": true
        }
    },
    "additionalProperties": false
}

逻辑说明 #

• 当newPrices长度=1时：thresholds可省略，符合基础规则；
• 当newPrices长度>1时：not关键字会排除「未提供thresholds」的情况，强制要求thresholds必须存在。

内容的提问来源于stack exchange，提问作者TomTommyTom