用于数组选项的 JSON Schema oneOf

Question

我正在尝试对 JSON 有效负载具有“步骤”数组且其内容可能只是预定义的一组选项之一的场景进行建模，例如：

{ "steps": ["s0"] } 
or
{ "steps": ["s1"] }
or
{ "steps": ["s0", "s2"] }

如何在架构中对此进行建模？以下：

{
  "$id": "https://example.com/person.schema.json",
  "$schema": "http://json-schema.org/draft-07/schema#",

  "title": "Payload",
  "type": "object",

  "properties": {
    "steps": {
      "type": "array",
      "oneOf": [
        ["s0"],
        ["s1"],
        ["s0", "s2"]
      ]
    }
  }
}     

失败，“读取架构时出现意外标记：StartArray.Path 'properties.steps.oneOf[0]'”

编辑

抱歉移动球门柱，我将我的问题简化为建议的解决方案适用于简化 版本但不是原版。更复杂的是，我需要 $ref 对象而不是 string 值...

示例输入：

{ "steps": [{"name": "S0"}] } 
or
{ "steps": [{"name": "S1"}] }
or
{ "steps": [{"name": "S1"}, {"name": "S2"}] }

与预期不匹配的架构（遵循 @EylM 的建议）

{
  "$id": "https://example.com/person.schema.json",
  "$schema": "http://json-schema.org/draft-07/schema#",
  "title": "Request",
  "type": "object",
  "properties": {
    "steps": {
      "type": "array",
      "oneOf": [
        {
          "const": [
            {"$ref": "#/definitions/s0"}
          ]
        },
        {
          "const": [
            {"$ref": "#/definitions/s1"}
          ]
        },
        {
          "const": [
            {"$ref": "#/definitions/s1"},
            {"$ref": "#/definitions/s2"}
          ]
        }
      ]
    }
  },
  "required": [
    "steps"
  ],
  "definitions": {
    "s0": {
      "type": "object",
      "properties": {"name": { "const": "S0" }}
    },
    "s1": {
      "type": "object",
      "properties": {"name": {"const": "S1" }}
    },
    "s2": {
      "type": "object",
      "properties": {"name": { "const": "S2" }}
      }
    }
}

使用此架构并输入 { "steps":[{"name": "s0"}] } 我得到 JSON 对来自 'oneOf' 的任何模式都有效

不管有什么价值，我都在使用https://www.jsonschemavalidator.net/ 进行实验。

Answer 1

根据您的编辑更新了我的答案。以下 JSON 模式验证了问题中的所有 3 个条件，我假设 { "steps": [{"name": "S2"}, {"name": "S1"}] } 无效。如果我错了，请纠正我。

{
  "$id": "https://example.com/person.schema.json",
  "$schema": "http://json-schema.org/draft-07/schema#",
  "title": "Request",
  "type": "object",
  "properties": {
    "steps": {
      "type": "array",
      "anyOf": [
        {
          "maxItems": 1,
          "items": {
            "oneOf": [
              {
                "$ref": "#/definitions/s0"
              },
              {
                "$ref": "#/definitions/s1"
              }
            ]
          }
        },
        {
          "minItems": 2,
          "maxItems": 2,
          "items": [
            {
              "$ref": "#/definitions/s1"
            },
            {
              "$ref": "#/definitions/s2"
            }
          ]
        }
      ]
    }
  },
  "required": [
    "steps"
  ],
  "definitions": {
    "s0": {
      "type": "object",
      "properties": {
        "name": {
          "const": "S0"
        }
      }
    },
    "s1": {
      "type": "object",
      "properties": {
        "name": {
          "const": "S1"
        }
      }
    },
    "s2": {
      "type": "object",
      "properties": {
        "name": {
          "const": "S2"
        }
      }
    }
  }
}

如果您想通过 { "steps": [{"name": "S2"}, {"name": "S1"}] } 的验证，请使用另一个 anyOf 块，如下所示。

{
    "minItems": 2,
    "maxItems": 2,
    "items": [
       {
          "$ref": "#/definitions/s2"
       },
       {
          "$ref": "#/definitions/s1"
       }
    ]
}

Answer 2

尝试使用枚举关键字。

enum 关键字用于将值限制为一组固定值。 它必须是一个至少包含一个元素的数组，其中每个元素是 独一无二。

json-schema - More info.

在您的情况下，JSON 看起来像：

{
  "$id": "https://example.com/person.schema.json",
  "$schema": "http://json-schema.org/draft-07/schema#",

  "title": "Payload",
  "type": "object",

  "properties": {
    "steps": {
      "type": "array",
      "oneOf": [
        {"enum": ["s1"]},
        {"enum": ["s0"]},
        {"enum": ["s1, s2"]}
      ]
    }
  }
}