From 76daf50876d3d908c2818ed3703467576ab93dde Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tomasz=20Drwi=C4=99ga?= <tomusdrw@users.noreply.github.com>
Date: Mon, 16 Jan 2017 10:49:27 +0100
Subject: [PATCH] Support HTML5-routed dapps (#4173)

---
 dapps/src/apps/mod.rs   |  1 +
 dapps/src/router/mod.rs | 24 ++++++++++++++++++++----
 dapps/src/web.rs        | 15 +++++++++++----
 3 files changed, 32 insertions(+), 8 deletions(-)

diff --git a/dapps/src/apps/mod.rs b/dapps/src/apps/mod.rs
index f32cf9042..462576a6e 100644
--- a/dapps/src/apps/mod.rs
+++ b/dapps/src/apps/mod.rs
@@ -38,6 +38,7 @@ pub const RPC_PATH: &'static str =  "rpc";
 pub const API_PATH: &'static str =  "api";
 pub const UTILS_PATH: &'static str =  "parity-utils";
 pub const WEB_PATH: &'static str = "web";
+pub const URL_REFERER: &'static str = "__referer=";
 
 pub fn utils() -> Box<Endpoint> {
 	Box::new(PageEndpoint::with_prefix(parity_ui::App::default(), UTILS_PATH.to_owned()))
diff --git a/dapps/src/router/mod.rs b/dapps/src/router/mod.rs
index 685b957d5..ac807967f 100644
--- a/dapps/src/router/mod.rs
+++ b/dapps/src/router/mod.rs
@@ -56,7 +56,6 @@ pub struct Router<A: Authorization + 'static> {
 impl<A: Authorization + 'static> server::Handler<HttpStream> for Router<A> {
 
 	fn on_request(&mut self, req: server::Request<HttpStream>) -> Next {
-
 		// Choose proper handler depending on path / domain
 		let url = handlers::extract_url(&req);
 		let endpoint = extract_endpoint(&url);
@@ -92,8 +91,7 @@ impl<A: Authorization + 'static> server::Handler<HttpStream> for Router<A> {
 		self.handler = match (endpoint.0, endpoint.1, referer) {
 			// Handle invalid web requests that we can recover from
 			(ref path, SpecialEndpoint::None, Some((ref referer, ref referer_url)))
-				if is_get_request
-					&& referer.app_id == apps::WEB_PATH
+				if referer.app_id == apps::WEB_PATH
 					&& self.endpoints.contains_key(apps::WEB_PATH)
 					&& !is_web_endpoint(path)
 				=>
@@ -225,10 +223,28 @@ fn extract_referer_endpoint(req: &server::Request<HttpStream>) -> Option<(Endpoi
 	let url = referer.and_then(|referer| Url::parse(&referer.0).ok());
 	url.and_then(|url| {
 		let option = Some(url);
-		extract_endpoint(&option).0.map(|endpoint| (endpoint, option.expect("Just wrapped; qed")))
+		extract_url_referer_endpoint(&option).or_else(|| {
+			extract_endpoint(&option).0.map(|endpoint| (endpoint, option.expect("Just wrapped; qed")))
+		})
 	})
 }
 
+fn extract_url_referer_endpoint(url: &Option<Url>) -> Option<(EndpointPath, Url)> {
+	let query = url.as_ref().and_then(|url| url.query.as_ref());
+	match (url, query) {
+		(&Some(ref url), Some(ref query)) if query.starts_with(apps::URL_REFERER) => {
+			let referer_url = format!("http://{}:{}/{}", url.host, url.port, &query[apps::URL_REFERER.len()..]);
+			debug!(target: "dapps", "Recovering referer from query parameter: {}", referer_url);
+
+			let referer_url = Url::parse(&referer_url).ok();
+			extract_endpoint(&referer_url).0.map(|endpoint| {
+				(endpoint, referer_url.expect("Endpoint returned only when url `is_some`").clone())
+			})
+		},
+		_ => None,
+	}
+}
+
 fn extract_endpoint(url: &Option<Url>) -> (Option<EndpointPath>, SpecialEndpoint) {
 	fn special_endpoint(url: &Url) -> SpecialEndpoint {
 		if url.path.len() <= 1 {
diff --git a/dapps/src/web.rs b/dapps/src/web.rs
index ac10b4d7f..377097aac 100644
--- a/dapps/src/web.rs
+++ b/dapps/src/web.rs
@@ -68,6 +68,7 @@ impl<F: Fetch> Endpoint for Web<F> {
 
 struct WebInstaller {
 	embeddable_on: Embeddable,
+	referer: String,
 }
 
 impl ContentValidator for WebInstaller {
@@ -84,7 +85,12 @@ impl ContentValidator for WebInstaller {
 			self.embeddable_on.clone(),
 		);
 		if is_html {
-			handler.set_initial_content(&format!(r#"<script src="/{}/inject.js"></script>"#, apps::UTILS_PATH));
+			handler.set_initial_content(&format!(
+				r#"<script src="/{}/inject.js"></script><script>history.replaceState({{}}, "", "/?{}{}")</script>"#,
+				apps::UTILS_PATH,
+				apps::URL_REFERER,
+				&self.referer,
+			));
 		}
 		Ok(ValidatorResponse::Streaming(handler))
 	}
@@ -108,7 +114,7 @@ struct WebHandler<F: Fetch> {
 }
 
 impl<F: Fetch> WebHandler<F> {
-	fn extract_target_url(&self, url: Option<Url>) -> Result<String, State<F>> {
+	fn extract_target_url(&self, url: Option<Url>) -> Result<(String, String), State<F>> {
 		let (path, query) = match url {
 			Some(url) => (url.path, url.query),
 			None => {
@@ -157,7 +163,7 @@ impl<F: Fetch> WebHandler<F> {
 			None => "".into(),
 		};
 
-		Ok(format!("{}://{}{}", protocol, path[idx + 2..].join("/"), query))
+		Ok((format!("{}://{}{}", protocol, path[idx + 2..].join("/"), query), path[0..].join("/")))
 	}
 }
 
@@ -166,7 +172,7 @@ impl<F: Fetch> server::Handler<net::HttpStream> for WebHandler<F> {
 		let url = extract_url(&request);
 
 		// First extract the URL (reject invalid URLs)
-		let target_url = match self.extract_target_url(url) {
+		let (target_url, referer) = match self.extract_target_url(url) {
 			Ok(url) => url,
 			Err(error) => {
 				self.state = error;
@@ -180,6 +186,7 @@ impl<F: Fetch> server::Handler<net::HttpStream> for WebHandler<F> {
 			self.control.clone(),
 			WebInstaller {
 				embeddable_on: self.embeddable_on.clone(),
+				referer: referer,
 			},
 			self.embeddable_on.clone(),
 			self.remote.clone(),