Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Web.DynamicData/DynamicData/SimpleFieldTemplateFactory.cs

@@ -0,0 +1,68 @@
+namespace System.Web.DynamicData {
+    using System;
+    using System.Collections.Generic;
+    using System.Linq;
+    using System.Text;
+    using System.Web.UI.WebControls;
+    using System.Web.Hosting;
+
+    // This FieldTemplateFactory is used for the simple cases where the user doesn't have
+    // a FieldTemplate directory but wants to get basic validation logic. In a sense
+    // it is a smarter version of a BoundField
+    internal class SimpleFieldTemplateFactory : FieldTemplateFactory {
+        private static bool? _directoryExists;
+
+        public SimpleFieldTemplateFactory()
+            : this(HostingEnvironment.VirtualPathProvider) {
+        }
+
+        internal SimpleFieldTemplateFactory(VirtualPathProvider vpp)
+            : base(vpp) {
+            VirtualPathProvider = vpp;
+        }
+
+        internal VirtualPathProvider VirtualPathProvider {
+            get;
+            set;
+        }
+
+        protected virtual bool DirectoryExists {
+            get {
+                if (!_directoryExists.HasValue) {
+                    // This is expensive so cache it.
+                    _directoryExists = VirtualPathProvider.DirectoryExists(TemplateFolderVirtualPath);
+                }
+                return _directoryExists.Value;
+            }
+        }
+
+        public override IFieldTemplate CreateFieldTemplate(MetaColumn column, DataBoundControlMode mode, string uiHint) {
+            // Call Preprocess mode so that we do set the right mode base on the the column's attributes
+            mode = PreprocessMode(column, mode);
+            bool readOnly = (mode == DataBoundControlMode.ReadOnly);
+            // If the folder doesn't exist use the fallback
+            if (!DirectoryExists) {
+                return CreateFieldTemplate(readOnly, column);
+            }
+
+            // Always see check if the base found anything first then fall back to the simple field template
+            IFieldTemplate fieldTemplate = base.CreateFieldTemplate(column, mode, uiHint);
+
+            // If there was no field template found and the user specified a uiHint then use the default behavior
+            if (!String.IsNullOrEmpty(uiHint)) {
+                return fieldTemplate;
+            }
+            
+            return fieldTemplate ?? CreateFieldTemplate(readOnly, column);
+        }
+
+        private IFieldTemplate CreateFieldTemplate(bool readOnly, MetaColumn column) {
+            // By default we'll support checkbox fields for boolean and a textbox for
+            // everything else
+            if (column.ColumnType == typeof(bool)) {
+                return SimpleFieldTemplateUserControl.CreateBooleanTemplate(readOnly);
+            }
+            return SimpleFieldTemplateUserControl.CreateTextTemplate(column, readOnly);
+        }
+    }
+}