Introduction

HTTP method override is a technique used to support clients that do not support certain HTTP methods such as PUT or DELETE. This is particularly useful for web browsers and older clients that only support GET and POST methods. The Iris web framework provides a robust and flexible method override middleware that allows developers to easily implement HTTP method overriding in their applications. This guide will walk you through the features and usage of the Iris method override middleware, helping you to understand and leverage its capabilities to enhance your web applications.

Features of Iris Method Override Middleware

The Iris method override middleware offers a variety of features to handle HTTP method overriding efficiently. These features include:

1. Customizable Methods: Define which HTTP methods can be overridden.
2. Custom Headers: Specify custom headers to determine the method override.
3. Form Field Support: Use form fields to specify the method override.
4. Query Parameter Support: Use query parameters to specify the method override.
5. Save Original Method: Optionally save the original HTTP method for later use.

Installation

To use the Iris method override middleware, you need to import it in your Iris application:

import "github.com/kataras/iris/v12/middleware/methodoverride"

Usage

Basic Setup

To use the method override middleware, you need to import the necessary packages and configure the middleware in your Iris application. Here is a basic example:

package main

import (
    "github.com/kataras/iris/v12"
    "github.com/kataras/iris/v12/middleware/methodoverride"
)

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

    // Create the method override middleware
    mo := methodoverride.New(
        methodoverride.SaveOriginalMethod("_originalMethod"),
    )

    // Register the middleware with UseRouter
    app.UseRouter(mo)

    app.Post("/path", func(ctx iris.Context) {
        ctx.WriteString("POST response")
    })

    app.Delete("/path", func(ctx iris.Context) {
        ctx.WriteString("DELETE response")
    })

    app.Listen(":8080")
}

Customizable Methods

You can define which HTTP methods can be overridden using the Methods option. By default, only the POST method can be overridden. Here is an example:

mo := methodoverride.New(
    methodoverride.Methods("POST", "PUT"),
)

Custom Headers

You can specify custom headers to determine the method override using the Headers option. By default, the middleware checks the following headers: X-HTTP-Method, X-HTTP-Method-Override, and X-Method-Override. Here is an example:

mo := methodoverride.New(
    methodoverride.Headers("X-Custom-Method"),
)

Form Field Support

You can use form fields to specify the method override using the FormField option. By default, the middleware checks the _method form field. Here is an example:

mo := methodoverride.New(
    methodoverride.FormField("_method"),
)

Query Parameter Support

You can use query parameters to specify the method override using the Query option. By default, the middleware checks the _method query parameter. Here is an example:

mo := methodoverride.New(
    methodoverride.Query("_method"),
)

Save Original Method

You can optionally save the original HTTP method for later use using the SaveOriginalMethod option. Here is an example:

mo := methodoverride.New(
    methodoverride.SaveOriginalMethod("_originalMethod"),
)

Example

Here is a complete example demonstrating how to use the method override middleware with an Iris application:

package main

import (
    "github.com/kataras/iris/v12"
    "github.com/kataras/iris/v12/middleware/methodoverride"
)

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

    // Create the method override middleware
    mo := methodoverride.New(
        methodoverride.SaveOriginalMethod("_originalMethod"),
    )

    // Register the middleware with UseRouter
    app.UseRouter(mo)

    app.Post("/path", func(ctx iris.Context) {
        ctx.WriteString("POST response")
    })

    app.Delete("/path", func(ctx iris.Context) {
        ctx.WriteString("DELETE response")
    })

    app.Listen(":8080")
}

Conclusion

The Iris method override middleware provides a simple and efficient way to support clients that do not support certain HTTP methods. By leveraging the features of this middleware, you can enhance the compatibility and flexibility of your web applications.