etag.md

ETag

ETag middleware for Fiber that lets caches be more efficient and save bandwidth, as a web server does not need to resend a full response if the content has not changed.

Table of Contents

• Signatures
• Examples
  • Default Config
  • Custom Config
• Config
• Default Config

Signatures

func New(config ...Config) fiber.Handler

Examples

Import the middleware package that is part of the Fiber web framework

import (
  "github.com/gofiber/fiber/v2"
  "github.com/gofiber/fiber/v2/middleware/etag"
)

After you initiate your Fiber app, you can use the following possibilities:

Default Config

app.Use(etag.New())

// Get / receives Etag: "13-1831710635" in response header
app.Get("/", func(c *fiber.Ctx) error {
	return c.SendString("Hello, World!")
})

Custom Config

app.Use(etag.New(etag.Config{
    Weak: true,
}))

// Get / receives Etag: "W/"13-1831710635" in response header
app.Get("/", func(c *fiber.Ctx) error {
	return c.SendString("Hello, World!")
})

Config

// Config defines the config for middleware.
type Config struct {
    // Next defines a function to skip this middleware when returned true.
    //
    // Optional. Default: nil
    Next func(c *fiber.Ctx) bool

    // Weak indicates that a weak validator is used. Weak etags are easy
    // to generate, but are far less useful for comparisons. Strong
    // validators are ideal for comparisons but can be very difficult
    // to generate efficiently. Weak ETag values of two representations
    // of the same resources might be semantically equivalent, but not
    // byte-for-byte identical. This means weak etags prevent caching
    // when byte range requests are used, but strong etags mean range
    // requests can still be cached.
    Weak bool
}

Default Config

var ConfigDefault = Config{
    Next: nil,
    Weak: false,
}