From 228c732e2e77d49bb06dccc5359bfd30ad7b4795 Mon Sep 17 00:00:00 2001
From: Curtis McEnroe <programble@gmail.com>
Date: Wed, 23 Dec 2015 22:38:14 -0500
Subject: [PATCH] Add JsonObjectHelper::get_string_option

---
 src/client/response.rs | 9 ++++++---
 src/error.rs           | 4 ++--
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/client/response.rs b/src/client/response.rs
index bca915c..09aafe2 100644
--- a/src/client/response.rs
+++ b/src/client/response.rs
@@ -73,10 +73,13 @@ impl<'a> JsonHelper<'a> {
 pub struct JsonObjectHelper<'a>(pub &'a json::Object);
 
 impl<'a> JsonObjectHelper<'a> {
+    /// Gets a field as a string or returns `None`.
+    pub fn get_string_option(&self, key: &'static str) -> Option<&'a str> {
+        self.0.get(key).and_then(Json::as_string)
+    }
+
     /// Gets a field as a string or fails with `ParseError::ExpectedFieldType`.
     pub fn get_string(&self, key: &'static str) -> Result<&'a str, ParseError> {
-        self.0.get(key)
-            .and_then(Json::as_string)
-            .ok_or(ParseError::ExpectedFieldType(key, "string"))
+        self.get_string_option(key).ok_or(ParseError::ExpectedFieldType(key, "string"))
     }
 }
diff --git a/src/error.rs b/src/error.rs
index 40e0416..7f92cfe 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -92,8 +92,8 @@ impl FromResponse for OAuth2Error {
         let obj = try!(json.as_object());
 
         let code = try!(obj.get_string("error"));
-        let description = obj.0.get("error_description").and_then(Json::as_string);
-        let uri = obj.0.get("error_uri").and_then(Json::as_string);
+        let description = obj.get_string_option("error_description");
+        let uri = obj.get_string_option("error_uri");
 
         Ok(OAuth2Error {
             code: code.into(),