reddraggone9/Cargo.toml

## Cargo.toml
[package]
name = "rocket-post-redirect"
version = "0.1.0"
authors = ["reddraggone9 <cljenkins9@gmail.com>"]

[dependencies]
rocket = "0.3.0"
rocket_codegen = "0.3.0"

## main.rs
//! A common pattern in web development has the server issue a [redirect after receiving a form
//! submission][0]. This is primarily intended to prevent refreshing the page from triggering a
//! scary browser dialog. However, it would appear that there is another option. Instead of
//! performing a redirect, the server could respond directly with the contents of the page it would
//! have redirected to and a bit of JavaScript which uses the history API to change the URL. This
//! gist compares the two approaches.
//!
//! [0]: https://en.wikipedia.org/wiki/Post/Redirect/Get
//!
//! Based on testing in Firefox, both methods:
//!
//! - don't resubmit the form if you refresh the page.
//! - send a request to `/get-after-redirect` when you refresh the page.
//! - show `/` followed by `/get-after-redirect` in global history.
//! - result in the back button returning to `/`. Going forward from that page
//!   returns you to `/get-after-redirect`, though a get request is only issued in
//!   the window.history case.
//! - show `/get-after-redirect` in the URL bar after form submission. Bookmarking
//!   the page also works correctly.
//!
//! ## Downsides ##
//!
//! ### Post/Redirect/Get ###
//! - Requires an extra round trip
//! - Requires the server to store data (e.g. flashes) between requests. Rocket can store flash
//!   strings in a cookie, but this has its own problems (e.g. has to be serialized to a string,
//!   cookie size limitations, avoidable data transfer both to and from the client, needs crypto
//!   to trust it).
//!
//! ### window.history ###
//! - Requires JavaScript
//! - Post handler must be able to "forward" to the other handler
//! - Going around HTTP like this feels blasphemous

#![feature(plugin)]
#![plugin(rocket_codegen)]

extern crate rocket;

use rocket::response::Redirect;
use rocket::response::content::Html;

fn main() {
    rocket::ignite()
        .mount("/", routes![
            index,
            post_and_redirect,
            get_after_redirect,
            replace_state,
        ])
        .launch();
}

#[get("/")]
fn index() -> Html<&'static str> {
    Html(r#"
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
  </head>
  <body>
    <form method="post">
        <button formaction="/post-and-redirect">
          POST with a redirect to update URL
        </button>
        <button formaction="/replace-state">
          POST with JavaScript to update URL
        </button>
    </form>
  </body>
</html>
"#)
}

#[post("/post-and-redirect")]
fn post_and_redirect() -> Redirect {
    Redirect::to("/get-after-redirect")
}

#[get("/get-after-redirect")]
fn get_after_redirect() -> Html<String> {
    redirect_success(None)
}

#[post("/replace-state")]
fn replace_state() -> Html<String> {
    // Upon reflection, I suppose there wouldn't be any harm in including this in the desired page
    // unconditionally.
    redirect_success(Some(r#"
      <script>window.history.replaceState(null, "", "/get-after-redirect")</script>
"#))
}

fn redirect_success(script: Option<&str>) -> Html<String> {
    Html(format!(r#"
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
  </head>
  <body>
    {}<p>Redirect successful.</p>
  </body>
</html>
"#, script.unwrap_or("")))
}
	[package]
	name = "rocket-post-redirect"
	version = "0.1.0"
	authors = ["reddraggone9 <cljenkins9@gmail.com>"]

	[dependencies]
	rocket = "0.3.0"
	rocket_codegen = "0.3.0"
	//! A common pattern in web development has the server issue a [redirect after receiving a form
	//! submission][0]. This is primarily intended to prevent refreshing the page from triggering a
	//! scary browser dialog. However, it would appear that there is another option. Instead of
	//! performing a redirect, the server could respond directly with the contents of the page it would
	//! have redirected to and a bit of JavaScript which uses the history API to change the URL. This
	//! gist compares the two approaches.
	//!
	//! [0]: https://en.wikipedia.org/wiki/Post/Redirect/Get
	//!
	//! Based on testing in Firefox, both methods:
	//!
	//! - don't resubmit the form if you refresh the page.
	//! - send a request to `/get-after-redirect` when you refresh the page.
	//! - show `/` followed by `/get-after-redirect` in global history.
	//! - result in the back button returning to `/`. Going forward from that page
	//! returns you to `/get-after-redirect`, though a get request is only issued in
	//! the window.history case.
	//! - show `/get-after-redirect` in the URL bar after form submission. Bookmarking
	//! the page also works correctly.
	//!
	//! ## Downsides ##
	//!
	//! ### Post/Redirect/Get ###
	//! - Requires an extra round trip
	//! - Requires the server to store data (e.g. flashes) between requests. Rocket can store flash
	//! strings in a cookie, but this has its own problems (e.g. has to be serialized to a string,
	//! cookie size limitations, avoidable data transfer both to and from the client, needs crypto
	//! to trust it).
	//!
	//! ### window.history ###
	//! - Requires JavaScript
	//! - Post handler must be able to "forward" to the other handler
	//! - Going around HTTP like this feels blasphemous

	#![feature(plugin)]
	#![plugin(rocket_codegen)]

	extern crate rocket;

	use rocket::response::Redirect;
	use rocket::response::content::Html;

	fn main() {
	rocket::ignite()
	.mount("/", routes![
	index,
	post_and_redirect,
	get_after_redirect,
	replace_state,
	])
	.launch();
	}

	#[get("/")]
	fn index() -> Html<&'static str> {
	Html(r#"
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8">
	</head>
	<body>
	<form method="post">
	<button formaction="/post-and-redirect">
	POST with a redirect to update URL
	</button>
	<button formaction="/replace-state">
	POST with JavaScript to update URL
	</button>
	</form>
	</body>
	</html>
	"#)
	}

	#[post("/post-and-redirect")]
	fn post_and_redirect() -> Redirect {
	Redirect::to("/get-after-redirect")
	}

	#[get("/get-after-redirect")]
	fn get_after_redirect() -> Html<String> {
	redirect_success(None)
	}

	#[post("/replace-state")]
	fn replace_state() -> Html<String> {
	// Upon reflection, I suppose there wouldn't be any harm in including this in the desired page
	// unconditionally.
	redirect_success(Some(r#"
	<script>window.history.replaceState(null, "", "/get-after-redirect")</script>
	"#))
	}

	fn redirect_success(script: Option<&str>) -> Html<String> {
	Html(format!(r#"
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8">
	</head>
	<body>
	{}<p>Redirect successful.</p>
	</body>
	</html>
	"#, script.unwrap_or("")))
	}