PowerApps自定义连接器调用翻译API时JSON解析错误求助

问题概述 #

在PowerApps中创建了调用语言翻译API的自定义连接器，连接器返回的响应符合预期，但调用时触发错误："JSON parsing error, expected 'string' but got 'array'"

请求示例 #

{
  "pipelineTasks": [
    {
      "taskType": "asr",
      "config": {
        "language": {
          "sourceLanguage": "hi"
        },
        "serviceId": "",
        "audioFormat": "flac",
        "samplingRate": 8000
      }
    },
    {
      "taskType": "translation",
      "config": {
        "language": {
          "sourceLanguage": "hi",
          "targetLanguage": "en"
        },
        "serviceId": ""
      }
    },
    {
      "taskType": "tts",
      "config": {
        "language": {
          "sourceLanguage": "en"
        },
        "serviceId": "",
        "gender": "female",
        "samplingRate": 8000
      }
    }
  ],
  "inputData": {
    "audio": [
      {
        "audioContent": "//base64 string"
      }
    ]
  }
}

响应示例 #

{
  "pipelineResponse": [
    {
      "taskType": "asr",
      "config": {
        "serviceId": "",
        "language": {
          "sourceLanguage": "hi",
          "sourceScriptCode": ""
        },
        "audioFormat": "flac",
        "encoding": null,
        "samplingRate": 8000,
        "postProcessors": null
      },
      "output": [
        {
          "source": "मेरा नाम महीर है और मैं भाषा वर्ष यूज़ कर रहा हूँ"
        }
      ],
      "audio": null
    },
    {
      "taskType": "translation",
      "config": null,
      "output": [
        {
          "source": "मेरा नाम महीर है और मैं भाषा वर्ष यूज़ कर रहा हूँ",
          "target": "My name is Maher and I'm using the language Year"
        }
      ],
      "audio": null
    },
    {
      "taskType": "tts",
      "config": {
        "language": {
          "sourceLanguage": "en",
          "sourceScriptCode": ""
        },
        "audioFormat": "wav",
        "encoding": "base64",
        "samplingRate": 8000,
        "postProcessors": null
      },
      "output": null,
      "audio": [
        {
          "audioContent": "//base64",
          "audioUri": null
        }
      ]
    }
  ]
}

问题根源 #

查看提供的Swagger定义，发现pipelineResponse.items.properties.output的类型被错误定义为string，但实际响应中output是数组类型（包含对象元素），部分场景下还会返回null，类型不匹配导致PowerApps解析JSON时出错。

原Swagger中错误的定义片段：

output:
  type: string
  description: output

修复方案 #

修改Swagger定义中output字段的类型，使其匹配实际响应结构：

output:
  type: array
  items:
    type: object
    properties:
      source:
        type: string
        description: Source text
      target:
        type: string
        description: Translated text
  x-nullable: true
  description: output

说明：

• 将type从string改为array，并定义数组元素的结构（包含source和可选的target字段）
• 添加x-nullable: true（Swagger 2.0中用于标记字段可返回null），适配tts任务中output为null的场景

修改后重新导入Swagger定义到PowerApps自定义连接器，即可解决JSON解析错误。

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