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package graphql_test
import (
"context"
"fmt"
"github.com/graph-gophers/graphql-go"
)
type (
user2 struct{ id, name, email string }
userResolver2 struct{ u user2 }
)
func (r *userResolver2) ID() graphql.ID { return graphql.ID(r.u.id) }
func (r *userResolver2) Name() *string { return &r.u.name }
func (r *userResolver2) Email() *string { return &r.u.email }
func (r *userResolver2) Friends(ctx context.Context) []*userResolver2 { return nil }
type root2 struct{}
func (r *root2) User(ctx context.Context, args struct{ ID string }) *userResolver2 {
if graphql.HasSelectedField(ctx, "email") {
fmt.Println("email requested")
}
if graphql.HasSelectedField(ctx, "friends") {
fmt.Println("friends requested")
}
return &userResolver2{u: user2{id: args.ID, name: "Alice", email: "a@example.com"}}
}
// Example_hasSelectedField demonstrates HasSelectedField helper for conditional
// logic without needing the full slice of field names. This can be handy when
// checking for a small number of specific fields (avoids allocating the names
// slice if it hasn't already been built).
func Example_hasSelectedField() {
const s = `
schema { query: Query }
type Query { user(id: ID!): User }
type User { id: ID! name: String email: String friends: [User!]! }
`
schema := graphql.MustParseSchema(s, &root2{})
// Select a subset of fields including a nested composite field; friends requires its own selection set.
query := `query { user(id: "U1") { id email friends { id } } }`
_ = schema.Exec(context.Background(), query, "", nil)
// Output:
// email requested
// friends requested
}
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