Custom Response Headers and Metadata in GoFr

GoFr simplifies the process of adding custom HTTP response headers and metadata to API responses using the Response struct. This feature allows you to include additional information such as custom headers or metadata to enhance client-server communication while keeping your data payload clean and structured.

Features

1. Custom Headers: Add key-value pairs for headers, useful for:

   • Security policies
   • Debugging information
   • Versioning details

   Type: map[string]string

   • Keys and values must be strings.

2. Metadata: Include optional contextual information like:

   • Deployment environment
   • Request-specific details (e.g., timestamps, tracing IDs)

   Type: map[string]any

   • Keys must be strings, and values can be of any type.

When metadata is included, the response structure is:

{
  "data": {},
  "metadata": {}
}

If metadata is omitted, the response defaults to:

{
  "data": {}
}

Example Usage

Adding Custom Headers and Metadata

To include custom headers and metadata in your response, populate the Headers and MetaData fields of the Response struct in your handler function.

package main

import (
	"time"

	"gofr.dev/pkg/gofr"
	"gofr.dev/pkg/gofr/http/response"
)

func main() {
	app := gofr.New()

	app.GET("/hello", HelloHandler)

	app.Run()
}

func HelloHandler(c *gofr.Context) (interface{}, error) {
	name := c.Param("name")
	if name == "" {
		c.Log("Name parameter is empty, defaulting to 'World'")
		name = "World"
	}

	// Define custom headers (map[string]string)
	headers := map[string]string{
		"X-Custom-Header":  "CustomValue",
		"X-Another-Header": "AnotherValue",
	}

	// Define metadata (map[string]any)
	metaData := map[string]any{
		"environment": "staging",
		"timestamp":   time.Now(),
	}

	// Return response with custom headers and metadata
	return response.Response{
		Data:     map[string]string{"message": "Hello, " + name + "!"},
		Metadata: metaData,
		Headers:  headers,
	}, nil
}

Example Responses

Response with Metadata:

When metadata is included, the response contains the metadata field:

{
  "data": {
    "message": "Hello, World!"
  },
  "metadata": {
    "environment": "staging",
    "timestamp": "2024-12-23T12:34:56Z"
  }
}

Response without Metadata:

If no metadata is provided, the response only includes the data field:

{
  "data": {
    "message": "Hello, World!"
  }
}

This functionality offers a convenient, structured way to include additional response information without altering the core data payload.