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scalagraphqlsangria

Know specified fields on serverside in GraphQL / Sangria-Graphql

When a client sends a request, I want to know what are the fields client has requested for data. For example,

{
  user {
    name
    address
  }
}

In the above request, client has requested name field and address field of the user. how do I know/get these specified fields i.e. name and address in the sangria-graphql Server while executing the query?

Solution

  • you have to use 4th parameter in resolve()

    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 */