Add FormTagHelper.

src/Microsoft.AspNet.Mvc.TagHelpers/FormTagHelper.cs

@@ -0,0 +1,132 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Microsoft.AspNet.Mvc.Rendering;
+using Microsoft.AspNet.Razor.Runtime.TagHelpers;
+using Microsoft.AspNet.Razor.TagHelpers;
+
+namespace Microsoft.AspNet.Mvc.TagHelpers
+{
+    /// <summary>
+    /// <see cref="ITagHelper"/> implementation targeting &lt;form&gt; elements.
+    /// </summary>
+    [ContentBehavior(ContentBehavior.Append)]
+    public class FormTagHelper : TagHelper
+    {
+        private const string RouteAttributePrefix = "route-";
+
+        [Activate]
+        private ViewContext ViewContext { get; set; }
+
+        [Activate]
+        private IHtmlGenerator Generator { get; set; }
+
+        /// <summary>
+        /// The name of the action method.
+        /// </summary>
+        /// <remarks>
+        /// If value contains a '/' this <see cref="ITagHelper"/> will do nothing.
+        /// </remarks>
+        public string Action { get; set; }
+
+        /// <summary>
+        /// The name of the controller.
+        /// </summary>
+        public string Controller { get; set; }
+
+        /// <summary>
+        /// The HTTP method for processing the form, either GET or POST.
+        /// </summary>
+        public string Method { get; set; }
+
+        /// <summary>
+        /// Whether the anti-forgery token should be generated. Defaults to <c>true</c> if <see cref="Action"/> is not
+        /// a URL, <c>false</c> otherwise.
+        /// </summary>
+        [HtmlAttributeName("anti-forgery")]
+        public bool? AntiForgery { get; set; }
+
+        /// <inheritdoc />
+        /// <remarks>Does nothing if <see cref="Action"/> contains a '/'.</remarks>
+        public override void Process(TagHelperContext context, TagHelperOutput output)
+        {
+            bool antiForgeryDefault = true;
+
+            var routePrefixedAttributes = output.FindPrefixedAttributes(RouteAttributePrefix);
+
+            // If Action contains a '/' it means the user is attempting to use the FormTagHelper as a normal form.
+            if (Action != null && Action.Contains('/'))
+            {
+                if (Controller != null || routePrefixedAttributes.Any())
+                {
+                    // We don't know how to generate a form action since a Controller attribute was also provided.
+                    throw new InvalidOperationException(
+                        Resources.FormatFormTagHelper_CannotDetermineAction(
+                            "<form>",
+                            nameof(Action).ToLowerInvariant(),
+                            nameof(Controller).ToLowerInvariant(),
+                            RouteAttributePrefix));
+                }
+
+                // User is using the FormTagHelper like a normal <form> tag, anti-forgery default should be false to 
+                // not force the anti-forgery token onto the user.
+                antiForgeryDefault = false;
+
+                // Restore Action, Method and Route HTML attributes if they were provided, user wants non-TagHelper <form>.
+                output.CopyHtmlAttribute(nameof(Action), context);
+
+                if (Method != null)
+                {
+                    output.CopyHtmlAttribute(nameof(Method), context);
+                }
+            }
+            else
+            {
+                var routeValues = GetRouteValues(output, routePrefixedAttributes);
+                var tagBuilder = Generator.GenerateForm(ViewContext,
+                                                        Action,
+                                                        Controller,
+                                                        routeValues,
+                                                        Method,
+                                                        htmlAttributes: null);
+
+                if (tagBuilder != null)
+                {
+                    // We don't want to do a full merge because we want the TagHelper content to take precedence.
+                    output.Merge(tagBuilder);
+                }
+            }
+
+            if (AntiForgery ?? antiForgeryDefault)
+            {
+                var antiForgeryTagBuilder = Generator.GenerateAntiForgery(ViewContext);
+                if (antiForgeryTagBuilder != null)
+                {
+                    output.Content += antiForgeryTagBuilder.ToString(TagRenderMode.SelfClosing);
+                }
+            }
+        }
+
+        // TODO: We will not need this method once https://github.com/aspnet/Razor/issues/89 is completed.
+        private static Dictionary<string, object> GetRouteValues(
+            TagHelperOutput output, IEnumerable<KeyValuePair<string, string>> routePrefixedAttributes)
+        {
+            Dictionary<string, object> routeValues = null;
+            if (routePrefixedAttributes.Any())
+            {
+                // Prefixed values should be treated as bound attributes, remove them from the output.
+                output.RemoveRange(routePrefixedAttributes);
+
+                // Generator.GenerateForm does not accept a Dictionary<string, string> for route values.
+                routeValues = routePrefixedAttributes.ToDictionary(
+                    attribute => attribute.Key.Substring(RouteAttributePrefix.Length),
+                    attribute => (object)attribute.Value);
+            }
+
+            return routeValues;
+        }
+    }
+}

src/Microsoft.AspNet.Mvc.TagHelpers/Resources.resx

@@ -0,0 +1,123 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!-- 
+    Microsoft ResX Schema 
+
+    Version 2.0
+
+    The primary goals of this format is to allow a simple XML format 
+    that is mostly human readable. The generation and parsing of the 
+    various data types are done through the TypeConverter classes 
+    associated with the data types.
+
+    Example:
+
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+
+    There are any number of "resheader" rows that contain simple 
+    name/value pairs.
+
+    Each data row contains a name, and value. The row also contains a 
+    type or mimetype. Type corresponds to a .NET class that support 
+    text/value conversion through the TypeConverter architecture. 
+    Classes that don't support this are serialized and stored with the 
+    mimetype set.
+
+    The mimetype is used for serialized objects, and tells the 
+    ResXResourceReader how to depersist the object. This is currently not 
+    extensible. For a given mimetype the value must be set accordingly:
+
+    Note - application/x-microsoft.net.object.binary.base64 is the format 
+    that the ResXResourceWriter will generate, however the reader can 
+    read any of the formats listed below.
+
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with 
+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with 
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array 
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <data name="FormTagHelper_CannotDetermineAction" xml:space="preserve">
+    <value>Cannot determine an {1} for {0}. A {0} with a URL-based {1} must not have attributes starting with {3} or a {2} attribute.</value>
+  </data>
+</root>