了解 GraphQL / Sangria-Graphql 中服务器端的特定字段

Know specified fields on serverside in GraphQL / Sangria-Graphql

当客户端发送请求时,我想知道客户端请求数据的字段是什么。例如,

{
  user {
    name
    address
  }
}

在上面的请求中,客户端请求了用户的name字段和address字段。我如何在执行查询时 know/get 这些指定字段,即 sangria-graphql 服务器中的名称和地址?

您必须在 resolve()

中使用 4th 参数
resolve: (obj, args, auth, fieldASTs) => {
    /* all your fields are present in selections
       please check the fieldASTs JSON path it may vary if you are using relay
                                                                connections */
  const requiredFields = fieldASTs.fieldNodes[0].selectionSet.selections.map(
      (set) => set.name.value
   );
  // requiredFields will contain the name and address
}
/* fieldASTs contains fieldNames, fieldNodes and every details about your Schema 
 you can get your specified fields inside fieldNodes like */