在GraphQL/Sangria-Graphql中知道服務器端指定的字段

Question

當客戶端發送請求時，我想知道客戶端請求數據的字段是什麼。例如，

{ 
    user { 
    name 
    address 
    } 
} 

在上述請求，客戶端已經請求name字段和用戶的address字段。在執行查詢時，我如何知道/獲取這些指定的字段，即sangria-graphql Server中的名稱和地址？

Answer 1

你必須使用4th參數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 */