Added FetchResponse.GetAttributeValue(string) method.

Resolves Trac issue #67.

2 files changed, 38 insertions, 0 deletions

diff --git a/src/DotNetOpenAuth.Test/OpenId/Extensions/AttributeExchange/FetchResponseTests.cs b/src/DotNetOpenAuth.Test/OpenId/Extensions/AttributeExchange/FetchResponseTests.cs
index d467186..0221ff4 100644
--- a/src/DotNetOpenAuth.Test/OpenId/Extensions/AttributeExchange/FetchResponseTests.cs
+++ b/src/DotNetOpenAuth.Test/OpenId/Extensions/AttributeExchange/FetchResponseTests.cs
@@ -40,6 +40,22 @@ namespace DotNetOpenId.Test.OpenId.Extensions {
 		}
 
 		[TestMethod]
+		public void GetAttributeValue() {
+			var response = new FetchResponse();
+
+			// Verify that null is returned if the attribute is absent.
+			Assert.IsNull(response.GetAttributeValue("http://someattribute"));
+
+			// Now add an attribute with no values.
+			response.Attributes.Add(new AttributeValues("http://someattribute2"));
+			Assert.IsNull(response.GetAttributeValue("http://someattribute2"));
+
+			// Now add an attribute with many values.
+			response.Attributes.Add(new AttributeValues("http://someattribute3", "a", "b", "c"));
+			Assert.AreEqual("a", response.GetAttributeValue("http://someattribute3"));
+		}
+
+		[TestMethod]
 		public void EqualityTests() {
 			var response1 = new FetchResponse();
 			var response2 = new FetchResponse();
diff --git a/src/DotNetOpenAuth/OpenId/Extensions/AttributeExchange/FetchResponse.cs b/src/DotNetOpenAuth/OpenId/Extensions/AttributeExchange/FetchResponse.cs
index 9413e2f..36c4d7c 100644
--- a/src/DotNetOpenAuth/OpenId/Extensions/AttributeExchange/FetchResponse.cs
+++ b/src/DotNetOpenAuth/OpenId/Extensions/AttributeExchange/FetchResponse.cs
@@ -81,6 +81,28 @@ namespace DotNetOpenAuth.OpenId.Extensions.AttributeExchange {
 		}
 
 		/// <summary>
+		/// Gets the first attribute value provided for a given attribute Type URI.
+		/// </summary>
+		/// <param name="typeUri">
+		/// The type URI of the attribute.  
+		/// Usually a constant from <see cref="WellKnownAttributes"/>.</param>
+		/// <returns>
+		/// The first value provided for the attribute, or <c>null</c> if the attribute is missing or no values were provided.
+		/// </returns>
+		/// <remarks>
+		/// This is meant as a helper method for the common case of just wanting one attribute value.
+		/// For greater flexibility or to retrieve more than just the first value for an attribute,
+		/// use the <see cref="Attributes"/> collection directly.
+		/// </remarks>
+		public string GetAttributeValue(string typeUri) {
+			if (this.Attributes.Contains(typeUri)) {
+				return this.Attributes[typeUri].Values.FirstOrDefault();
+			} else {
+				return null;
+			};
+		}
+
+		/// <summary>
 		/// Determines whether the specified <see cref="T:System.Object"/> is equal to the current <see cref="T:System.Object"/>.
 		/// </summary>
 		/// <param name="obj">The <see cref="T:System.Object"/> to compare with the current <see cref="T:System.Object"/>.</param>