From c696855bc4c6002f020a262e011acf3b3ca4d205 Mon Sep 17 00:00:00 2001
From: Markus Kohlhase <mail@markus-kohlhase.de>
Date: Fri, 25 Nov 2016 16:23:31 +0100
Subject: [PATCH] support url generation for mounted routers

---
 .travis.yml    | 16 ++++++++++++++-
 Cargo.toml     |  1 +
 src/lib.rs     |  3 +++
 src/url_for.rs | 54 ++++++++++++++++++++++++++++++++++++++++++++++----
 4 files changed, 69 insertions(+), 5 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 7a6dcc0..52dc06e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,8 +4,22 @@ rust:
   - stable
   - beta
 sudo: false
+
+# load travis-cargo
+before_script:
+  - |
+      pip install 'travis-cargo<0.2' --user &&
+      export PATH=$HOME/.local/bin:$PATH
+
+script:
+  - |
+      travis-cargo build -- --features mount &&
+      travis-cargo test -- --features mount &&
+      travis-cargo --only stable doc
+
 env:
   global:
-    secure: MjdqCPMV5iaByoY3m545Iw/S7UHbX5d3ZgU9H3c62Vo2WqJ12EWk4H0Z0HU+Ptu1+FriplfbnKKcfiE9zHam2yBs2XfhysWm/nOCk5eTetSpapYddWkwQaoEgxcan4kUyJiG0v4ZylorZea7d2wa9iKZKFQPChnvCI+Xd/9dlJs=
+    - TRAVIS_CARGO_NIGHTLY_FEATURE=""
+    - secure: MjdqCPMV5iaByoY3m545Iw/S7UHbX5d3ZgU9H3c62Vo2WqJ12EWk4H0Z0HU+Ptu1+FriplfbnKKcfiE9zHam2yBs2XfhysWm/nOCk5eTetSpapYddWkwQaoEgxcan4kUyJiG0v4ZylorZea7d2wa9iKZKFQPChnvCI+Xd/9dlJs=
 after_success: 'curl https://raw.githubusercontent.com/iron-bot/build-doc/master/build-doc.sh
   | sh '
diff --git a/Cargo.toml b/Cargo.toml
index 440412e..1231be8 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -13,3 +13,4 @@ keywords = ["iron", "web", "http", "routing", "router"]
 route-recognizer = "0.1"
 iron = "0.4"
 url = "1.1"
+mount = { version = "0.2", optional = true }
diff --git a/src/lib.rs b/src/lib.rs
index c8b6d16..f54b4c2 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -6,10 +6,13 @@
 extern crate iron;
 extern crate route_recognizer as recognizer;
 extern crate url;
+#[cfg(feature = "mount")]
+extern crate mount;
 
 pub use router::{Router, RouterError, NoRoute, TrailingSlash};
 pub use recognizer::Params;
 pub use url_for::url_for;
+pub use url_for::mounted_url_for;
 
 mod router;
 mod macros;
diff --git a/src/url_for.rs b/src/url_for.rs
index fd23d67..3fe63bc 100644
--- a/src/url_for.rs
+++ b/src/url_for.rs
@@ -4,6 +4,8 @@ use url::Url;
 
 use iron::prelude::*;
 use router::RouterInner;
+#[cfg(feature = "mount")]
+use mount::OriginalUrl;
 
 /// Generate a URL based off of the currently requested URL.
 ///
@@ -12,19 +14,48 @@ use router::RouterInner;
 /// `params` will be inserted as route parameters if fitting, the rest will be appended as query
 /// parameters.
 pub fn url_for(request: &Request, route_id: &str, params: HashMap<String, String>) -> ::iron::Url {
+    let url = request.url.clone().into_generic_url();
+    _url_for(url, request, route_id, params)
+}
+
+/// Generate a URL based off of the currently requested URL.
+/// In contrast to `url_for` this method respects the hidden path if the router is mounted.
+///
+/// The `route_id` used during route registration will be used here again.
+///
+/// `params` will be inserted as route parameters if fitting, the rest will be appended as query
+/// parameters.
+#[cfg(feature = "mount")]
+pub fn mounted_url_for(request: &Request, route_id: &str, params: HashMap<String, String>) -> ::iron::Url {
+    let url = request.extensions.get::<OriginalUrl>().unwrap().clone().into_generic_url();
+    _url_for(url, request, route_id, params)
+}
+
+fn _url_for(mut url: Url, request: &Request, route_id: &str, params: HashMap<String, String>) -> ::iron::Url {
     let inner = request.extensions.get::<RouterInner>().expect("Couldn\'t find router set up properly.");
     let glob = inner.route_ids.get(route_id).expect("No route with that ID");
 
-    let mut url = request.url.clone().into_generic_url();
     url_for_impl(&mut url, glob, params);
     ::iron::Url::from_generic_url(url).unwrap()
 }
 
 fn url_for_impl(url: &mut Url, glob: &str, mut params: HashMap<String, String>) {
     {
+        let globs = glob.split('/');
+        let globs_count = globs.clone().filter(|x| *x != "").count();
+        let segments_count = url.path_segments().unwrap().count();
         let mut url_path_segments = url.path_segments_mut().unwrap();
-        url_path_segments.clear();
-        for path_segment in glob.split('/') {
+
+        if globs_count < segments_count {
+            for _ in 0..globs_count+1 {
+                url_path_segments.pop();
+            }
+        } else {
+            url_path_segments.clear();
+        }
+
+        let mut idx = 0;
+        for path_segment in globs {
             if path_segment.len() > 1 && (path_segment.starts_with(':') || path_segment.starts_with('*')) {
                 let key = &path_segment[1..];
                 match params.remove(key) {
@@ -32,7 +63,11 @@ fn url_for_impl(url: &mut Url, glob: &str, mut params: HashMap<String, String>)
                     None => panic!("No value for key {}", key)
                 };
             } else {
-                url_path_segments.push(path_segment);
+                if idx == 0 && path_segment == "" {
+                  idx += 1;
+                } else {
+                  url_path_segments.push(path_segment);
+                }
             }
         }
     }
@@ -73,4 +108,15 @@ mod test {
         });
         assert_eq!(url.to_string(), "http://localhost/foo/bam/");
     }
+
+    #[test]
+    fn test_with_mount() {
+        let mut url = "http://localhost/mounted/foo/bar/baz".parse().unwrap();
+        url_for_impl(&mut url, "/foo/:user/", {
+            let mut rv = HashMap::new();
+            rv.insert("user".into(), "bam".into());
+            rv
+        });
+        assert_eq!(url.to_string(), "http://localhost/mounted/foo/bam/");
+    }
 }