Implementing FindsBySequence attribute for .NET PageFactory

Allows the user to mark a field or property in a page object such that
any FindsBy attributes set on the member are used in sequence, as
specified by the Priority property. Note that when not specifying a
Priority value, or specifying multiple FindsBy attributes with the same
Priority value, the behavior is undefined.

Author: jimevans

dotnet/src/support/PageObjects/FindsBySequenceAttribute.cs

@@ -0,0 +1,52 @@
+// <copyright file="FindsBySequenceAttribute.cs" company="WebDriver Committers">
+// Copyright 2007-2011 WebDriver committers
+// Copyright 2007-2011 Google Inc.
+// Portions copyright 2011 Software Freedom Conservancy
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// </copyright>
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace OpenQA.Selenium.Support.PageObjects
+{
+    /// <summary>
+    /// Marks elements to indicate that each <see cref="FindsByAttribute"/> on the field or
+    /// property should be used in sequence to find the appropriate element.
+    /// </summary>
+    /// <remarks>
+    /// <para>
+    /// When used with a set of <see cref="FindsByAttribute"/>, the criteria are used
+    /// in sequence according to the Priority property to find child elements. Note that
+    /// the behavior when setting multiple <see cref="FindsByAttribute"/> Priority
+    /// properties to the same value, or not specifying a Priority value, is undefined.
+    /// </para>
+    /// <para>
+    /// <code>
+    /// // Will find the element with the ID attribute matching "elementId", then will find
+    /// // a child element with the ID attribute matching "childElementId".
+    /// [FindsBySequence]
+    /// [FindsBy(How = How.Id, Using = "elementId", Priority = 0)]
+    /// [FindsBy(How = How.Id, Using = "childElementId", Priority = 1)]
+    /// public IWebElement thisElement;
+    /// </code>
+    /// </para>
+    /// </remarks>
+    [AttributeUsage(AttributeTargets.Field | AttributeTargets.Property)]
+    public sealed class FindsBySequenceAttribute : Attribute
+    {
+    }
+}

dotnet/src/support/PageObjects/PageFactory.cs

@@ -136,6 +136,9 @@ public static void InitElements(ISearchContext driver, object page)
 
         private static List<By> CreateLocatorList(MemberInfo member)
         {
+            var useSequenceAttributes = Attribute.GetCustomAttributes(member, typeof(FindsBySequenceAttribute), true);
+            bool useSequence = useSequenceAttributes.Length > 0;
+
             List<By> bys = new List<By>();
             var attributes = Attribute.GetCustomAttributes(member, typeof(FindsByAttribute), true);
             if (attributes.Length > 0)
@@ -151,6 +154,13 @@ private static List<By> CreateLocatorList(MemberInfo member)
 
                     bys.Add(castedAttribute.Finder);
                 }
+
+                if (useSequence)
+                {
+                    ByChained chained = new ByChained(bys.ToArray());
+                    bys.Clear();
+                    bys.Add(chained);
+                }
             }
 
             return bys;

dotnet/src/support/WebDriver.Support.csproj

@@ -81,6 +81,7 @@
     <Compile Include="PageObjects\ByFactory.cs" />
     <Compile Include="PageObjects\CacheLookupAttribute.cs" />
     <Compile Include="PageObjects\FindsByAttribute.cs" />
+    <Compile Include="PageObjects\FindsBySequenceAttribute.cs" />
     <Compile Include="PageObjects\How.cs" />
     <Compile Include="PageObjects\PageFactory.cs" />
     <Compile Include="PageObjects\WebElementListProxy.cs" />

dotnet/test/support/PageObjects/PageFactoryBrowserTest.cs

@@ -90,13 +90,27 @@ public void ShouldFindMultipleElements()
             Assert.AreEqual("Open new window", page.AllLinks[0].Text.Trim());
         }
 
+        [Test]
+        public void ShouldFindElementUsingSequence()
+        {
+            driver.Url = xhtmlTestPage;
+            var page = new PageFactoryBrowserTest.Page();
+            PageFactory.InitElements(driver, page);
+            Assert.AreEqual("I'm a child", page.NestedElement.Text.Trim());
+        }
+
         #region Page classes for tests
         #pragma warning disable 649 //We set fields through reflection, so expect an always-null warning
 
         private class Page
         {
             [FindsBy(How = How.Name, Using = "someForm")]
             public IWebElement formElement;
+
+            [FindsBySequence]
+            [FindsBy(How = How.Id, Using = "parent", Priority = 0)]
+            [FindsBy(How = How.Id, Using = "child", Priority = 1)]
+            public IWebElement NestedElement;
         }
 
         private class HoverPage