context

Context Example

This example demonstrates two ways to pass context (like authenticated users) to GraphQL resolvers in Rocket.

Patterns

Option 1: Middleware Pattern (Recommended)

Use standard HTTP middleware to enrich the request context before it reaches Rocket.

Pros:

• Standard Go pattern
• Works with any router/framework
• Easy to compose multiple middlewares
• Testable independently

Example:

func AuthMiddleware(next http.Handler) http.Handler {
    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        token := r.Header.Get("Authorization")
        userID, _ := verifyJWT(token)
        
        ctx := context.WithValue(r.Context(), UserIDKey, userID)
        next.ServeHTTP(w, r.WithContext(ctx))
    })
}

handler := rocket.Handler(schema)
handler = AuthMiddleware(handler)
http.Handle("/graphql", handler)

Option 2: Context Builder (Apollo-style)

Configure a context builder function in the schema config.

Pros:

• Similar to Apollo GraphQL pattern
• All context logic in one place
• No separate middleware needed

Example:

schema, _ := rocket.BuildSchema(
    rocket.Config{
        SchemaPath: "schema.graphql",
        ContextBuilder: func(r *http.Request) context.Context {
            ctx := r.Context()
            token := r.Header.Get("Authorization")
            userID, _ := verifyJWT(token)
            return context.WithValue(ctx, UserIDKey, userID)
        },
    },
    resolvers,
)

Running the Example

go run main.go

Then visit http://localhost:8080 to use the GraphQL playground.

Testing Queries

Public Query (no auth required)

{
  hello
}

Protected Queries (require authentication)

Add this header in the playground:

{
  "Authorization": "Bearer YOUR_TOKEN"
}

Then run:

{
  currentUser {
    id
    name
    email
  }
}

Or:

{
  me {
    id
    name
    email
  }
}

Switching Patterns

In main.go, uncomment the pattern you want to try:

// Option 1: Middleware
runWithMiddleware()

// Option 2: Context Builder
// runWithContextBuilder()

Both produce the same result - choose based on your preference!

See Also

• Context Documentation
• Resolvers Guide