Implement FromResponse for tokens

src/client/response.rs

@@ -82,4 +82,14 @@ impl<'a> JsonObjectHelper<'a> {
     pub fn get_string(&self, key: &'static str) -> Result<&'a str, ParseError> {
         self.get_string_option(key).ok_or(ParseError::ExpectedFieldType(key, "string"))
     }
+
+    /// Gets a field as an i64 or returns `None`.
+    pub fn get_i64_option(&self, key: &'static str) -> Option<i64> {
+        self.0.get(key).and_then(Json::as_i64)
+    }
+
+    /// Gets a field as an i64 or fails with `ParseError::ExpectedFieldType`.
+    pub fn get_i64(&self, key: &'static str) -> Result<i64, ParseError> {
+        self.get_i64_option(key).ok_or(ParseError::ExpectedFieldType(key, "i64"))
+    }
 }

src/token/bearer.rs

@@ -1,6 +1,8 @@
 use hyper::header;
+use rustc_serialize::json::Json;
 
 use super::{Token, Lifetime};
+use client::response::{FromResponse, ParseError, JsonHelper};
 
 /// The bearer token type.
 ///
@@ -23,3 +25,35 @@ impl<'a, L: Lifetime> Into<header::Authorization<header::Bearer>> for &'a Bearer
         header::Authorization(header::Bearer { token: self.access_token.clone() })
     }
 }
+
+impl<L: Lifetime> Bearer<L> {
+    fn from_response_and_lifetime(json: &Json, lifetime: L) -> Result<Self, ParseError> {
+        let obj = try!(JsonHelper(json).as_object());
+
+        let token_type = try!(obj.get_string("token_type"));
+        if token_type != "Bearer" && token_type != "bearer" {
+            return Err(ParseError::ExpectedFieldValue("token_type", "Bearer"));
+        }
+
+        let access_token = try!(obj.get_string("access_token"));
+        let scope = obj.get_string_option("scope");
+
+        Ok(Bearer {
+            access_token: access_token.into(),
+            scope: scope.map(Into::into),
+            lifetime: lifetime,
+        })
+    }
+}
+
+impl<L: Lifetime> FromResponse for Bearer<L> {
+    fn from_response(json: &Json) -> Result<Self, ParseError> {
+        let lifetime = try!(FromResponse::from_response(json));
+        Bearer::from_response_and_lifetime(json, lifetime)
+    }
+
+    fn from_response_inherit(json: &Json, prev: &Self) -> Result<Self, ParseError> {
+        let lifetime = try!(FromResponse::from_response_inherit(json, &prev.lifetime));
+        Bearer::from_response_and_lifetime(json, lifetime)
+    }
+}

src/token/expiring.rs

@@ -1,6 +1,8 @@
-use chrono::{DateTime, UTC};
+use chrono::{DateTime, UTC, Duration};
+use rustc_serialize::json::Json;
 
 use super::Lifetime;
+use client::response::{FromResponse, ParseError, JsonHelper};
 
 /// An expiring token.
 #[derive(Debug)]
@@ -22,3 +24,32 @@ impl Expiring {
 impl Lifetime for Expiring {
     fn expired(&self) -> bool { self.expires < UTC::now() }
 }
+
+impl FromResponse for Expiring {
+    fn from_response(json: &Json) -> Result<Self, ParseError> {
+        let obj = try!(JsonHelper(json).as_object());
+
+        let refresh_token = try!(obj.get_string("refresh_token"));
+        let expires_in = try!(obj.get_i64("expires_in"));
+
+        Ok(Expiring {
+            refresh_token: refresh_token.into(),
+            expires: UTC::now() + Duration::seconds(expires_in),
+        })
+    }
+
+    fn from_response_inherit(json: &Json, prev: &Self) -> Result<Self, ParseError> {
+        let obj = try!(JsonHelper(json).as_object());
+
+        let refresh_token = try! {
+            obj.get_string("refresh_token")
+                .or(Ok(&prev.refresh_token))
+        };
+        let expires_in = try!(obj.get_i64("expires_in"));
+
+        Ok(Expiring {
+            refresh_token: refresh_token.into(),
+            expires: UTC::now() + Duration::seconds(expires_in),
+        })
+    }
+}

src/token/mod.rs

@@ -5,10 +5,12 @@
 //!
 //! Expiring and non-expiring tokens are abstracted through the `Lifetime` trait.
 
+use client::response::FromResponse;
+
 /// OAuth 2.0 tokens.
 ///
 /// See [RFC 6749, section 5](http://tools.ietf.org/html/rfc6749#section-5).
-pub trait Token<L: Lifetime> {
+pub trait Token<L: Lifetime>: FromResponse {
     /// Returns the access token.
     ///
     /// See [RF C6749, section 1.4](http://tools.ietf.org/html/rfc6749#section-1.4).
@@ -22,7 +24,7 @@ pub trait Token<L: Lifetime> {
 }
 
 /// OAuth 2.0 token lifetimes.
-pub trait Lifetime {
+pub trait Lifetime: FromResponse {
     /// Returns true if the access token is no longer valid.
     fn expired(&self) -> bool;
 }

src/token/statik.rs

@@ -1,4 +1,7 @@
+use rustc_serialize::json::Json;
+
 use super::Lifetime;
+use client::response::{FromResponse, ParseError, JsonHelper};
 
 /// A static, non-expiring token.
 #[derive(Debug)]
@@ -7,3 +10,13 @@ pub struct Static;
 impl Lifetime for Static {
     fn expired(&self) -> bool { false }
 }
+
+impl FromResponse for Static {
+    fn from_response(json: &Json) -> Result<Self, ParseError> {
+        let obj = try!(JsonHelper(json).as_object());
+        if obj.0.contains_key("expires_in") {
+            return Err(ParseError::UnexpectedField("expires_in"));
+        }
+        Ok(Static)
+    }
+}