Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Web/UI/WebControls/ModelMethodContext.cs

@@ -0,0 +1,80 @@
+namespace System.Web.UI.WebControls {
+    using System;
+    using System.Web.ModelBinding;
+
+    /// <summary>
+    /// Used to invoke <see cref='System.Web.UI.Page.UpdateModel' />/<see cref='System.Web.UI.Page.TryUpdateModel' /> 
+    /// methods where <see cref='System.Web.UI.Page' /> is directly not accessible.
+    /// An example is a custom class defining the Select/Update/Delete/InsertMethod properties for 
+    /// data binding can have a parameter of type <see cref='System.Web.UI.WebControls.ModelMethodContext' />
+    /// in the above methods and use it to invoke the above methods. Alternately instead of a method parameter,
+    /// <see cref='System.Web.UI.WebControls.ModelMethodContext.Current' /> can also be used within the 
+    /// Select/Update/Delete/InsertMethod code to invoke TryUpdateModel/UpdateModel methods.
+    /// </summary>
+    public class ModelMethodContext {
+        private Page _page;
+
+        public ModelMethodContext(Page page) {
+            if (page == null) {
+                throw new ArgumentNullException("page");
+            }
+
+            _page = page;
+        }
+
+        public ModelStateDictionary ModelState {
+            get {
+                return _page.ModelState;
+            }
+        }
+
+        /// <summary>
+        /// Gets the ModelMethodContext corresponding to the <see cref='System.Web.UI.Page' /> from <see cref='System.Web.HttpContext.Current' />.
+        /// Can be null when the current request is not for a <see cref='System.Web.UI.Page' />.
+        /// </summary>
+        public static ModelMethodContext Current {
+            get {
+                Page page = HttpContext.Current.Handler as Page;
+                if (page != null) {
+                    return new ModelMethodContext(page);
+                }
+
+                return null;
+            }
+        }
+
+        /// <summary>
+        /// Updates the model object from the values within a databound control. This must be invoked 
+        /// within the Select/Update/Delete/InsertMethods used for data binding.
+        /// Throws an exception if the update fails.
+        /// </summary>
+        public virtual void UpdateModel<TModel>(TModel model) where TModel : class {
+            _page.UpdateModel<TModel>(model);
+        }
+
+        /// <summary>
+        /// Updates the model object from the values provided by given valueProvider.
+        /// Throws an exception if the update fails.
+        /// </summary>
+        public virtual void UpdateModel<TModel>(TModel model, IValueProvider valueProvider) where TModel : class {
+            _page.UpdateModel<TModel>(model, valueProvider);
+        }
+
+        /// <summary>
+        /// Attempts to update the model object from the values provided by given valueProvider.
+        /// </summary>
+        /// <returns>True if the model object is updated succesfully with valid values. False otherwise.</returns>
+        public virtual bool TryUpdateModel<TModel>(TModel model) where TModel : class {
+            return _page.TryUpdateModel<TModel>(model);
+        }
+
+        /// <summary>
+        /// Attempts to update the model object from the values within a databound control. This
+        /// must be invoked within the Select/Update/Delete/InsertMethods used for data binding. 
+        /// </summary>
+        /// <returns>True if the model object is updated succesfully with valid values. False otherwise.</returns>
+        public virtual bool TryUpdateModel<TModel>(TModel model, IValueProvider valueProvider) where TModel : class {
+            return _page.TryUpdateModel<TModel>(model, valueProvider);
+        }
+    }
+}