ios - 如何调用 graphql API

Question

如何在 View Controller 中调用 graphql API。我正在调用如下结构的 API

let url = URL(string: "http://xxxx.com/graphql")!

var request = URLRequest(url: url)
request.httpMethod = "POST"

let query = "{query:mutation {\n  signin(email: \"adc.inlove@gmail.com\", password: \"qwerty\") {\n    result {\n      token\n      firstName\n      lastName\n      profileImage\n      status\n    }\n  }\n}\n}"
let body = ["query": query]
request.httpBody = try! JSONSerialization.data(withJSONObject: body, options: [])
request.cachePolicy = .reloadIgnoringLocalCacheData

let task = URLSession.shared.dataTask(with: request, completionHandler: { data, _, error in
    if let error = error { print(error); return }
    guard let data = data else { print("Data is missing."); return }
    do {
        let json = try JSONSerialization.jsonObject(with: data, options: .allowFragments)
        print(json)
    } catch let e {
        print("Parse error: \(e)")
    }
})
task.resume()`

但它显示错误为，

Error Domain=NSCocoaErrorDomain Code=3840 "Invalid value around character 0." UserInfo={NSDebugDescription=Invalid value around character 0.}

而且它在 postman 和获取输出中也能完美运行。任何人都请帮助我找出解决方案。

Answer 1

这是您当前发送的文档:

{
  query:mutation  {
    signin(email: "adc.inlove@gmail.com", password: "qwerty") {
      result {
        token
        firstName
        lastName
        profileImage
        status
      }
    }
  }
}

这不是 GraphQL 文档的正确语法。根据规范，文档应具有以下格式:

OperationType [Name] [VariableDefinitions] [Directives] SelectionSet

其中括号表示可选元素，操作类型是query、mutation或subscription之一，选择集是一个或多个字段包裹在一组大括号中。

如果省略操作类型，则文档被假定为查询。这被称为“查询速记”。所以给出一个有效的查询，如:

query SomeOperationName {
  users {
    name
  }
}

下面是等价的:

{
  users {
    name
  }
}

不过，以上仅适用于查询，不适用于突变。综上所述，您的文档有一组额外的大括号和无效的操作类型。至少，将其更改为:

mutation {
  signin (email: "adc.inlove@gmail.com", password: "qwerty") {
    result {
      token
      firstName
      lastName
      profileImage
      status
    }
  }
}

或者...

let query = "mutation { signin(email: \"adc.inlove@gmail.com\", password: \"qwerty\") { result { token firstName lastName profileImage status } } }"