Add page to AnchorTagHelper and FormTagHelper

Fixes #6088

src/Microsoft.AspNetCore.Mvc.TagHelpers/AnchorTagHelper.cs

@@ -16,6 +16,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
     [HtmlTargetElement("a", Attributes = ActionAttributeName)]
     [HtmlTargetElement("a", Attributes = ControllerAttributeName)]
     [HtmlTargetElement("a", Attributes = AreaAttributeName)]
+    [HtmlTargetElement("a", Attributes = PageAttributeName)]
     [HtmlTargetElement("a", Attributes = FragmentAttributeName)]
     [HtmlTargetElement("a", Attributes = HostAttributeName)]
     [HtmlTargetElement("a", Attributes = ProtocolAttributeName)]
@@ -27,6 +28,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         private const string ActionAttributeName = "asp-action";
         private const string ControllerAttributeName = "asp-controller";
         private const string AreaAttributeName = "asp-area";
+        private const string PageAttributeName = "asp-page";
         private const string FragmentAttributeName = "asp-fragment";
         private const string HostAttributeName = "asp-host";
         private const string ProtocolAttributeName = "asp-protocol";
@@ -59,24 +61,40 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         /// <summary>
         /// The name of the action method.
         /// </summary>
-        /// <remarks>Must be <c>null</c> if <see cref="Route"/> is non-<c>null</c>.</remarks>
+        /// <remarks>
+        /// Must be <c>null</c> if <see cref="Route"/> or <see cref="Page"/> is non-<c>null</c>.
+        /// </remarks>
         [HtmlAttributeName(ActionAttributeName)]
         public string Action { get; set; }
 
         /// <summary>
         /// The name of the controller.
         /// </summary>
-        /// <remarks>Must be <c>null</c> if <see cref="Route"/> is non-<c>null</c>.</remarks>
+        /// <remarks>
+        /// Must be <c>null</c> if <see cref="Route"/> or <see cref="Page"/> is non-<c>null</c>.
+        /// </remarks>
         [HtmlAttributeName(ControllerAttributeName)]
         public string Controller { get; set; }
 
         /// <summary>
         /// The name of the area.
         /// </summary>
-        /// <remarks>Must be <c>null</c> if <see cref="Route"/> is non-<c>null</c>.</remarks>
+        /// <remarks>
+        /// Must be <c>null</c> if <see cref="Route"/> or <see cref="Page"/> is non-<c>null</c>.
+        /// </remarks>
         [HtmlAttributeName(AreaAttributeName)]
         public string Area { get; set; }
 
+        /// <summary>
+        /// The name of the page.
+        /// </summary>
+        /// <remarks>
+        /// Must be <c>null</c> if <see cref="Route"/> or <see cref="Action"/>, <see cref="Controller"/>
+        /// or <see cref="Area"/> is non-<c>null</c>.
+        /// </remarks>
+        [HtmlAttributeName(PageAttributeName)]
+        public string Page { get; set; }
+
         /// <summary>
         /// The protocol for the URL, such as &quot;http&quot; or &quot;https&quot;.
         /// </summary>
@@ -99,7 +117,8 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         /// Name of the route.
         /// </summary>
         /// <remarks>
-        /// Must be <c>null</c> if <see cref="Action"/> or <see cref="Controller"/> is non-<c>null</c>.
+        /// Must be <c>null</c> if one of <see cref="Action"/>, <see cref="Controller"/>, <see cref="Area"/> 
+        /// or <see cref="Page"/> is non-<c>null</c>.
         /// </remarks>
         [HtmlAttributeName(RouteAttributeName)]
         public string Route { get; set; }
@@ -134,12 +153,6 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
 
         /// <inheritdoc />
         /// <remarks>Does nothing if user provides an <c>href</c> attribute.</remarks>
-        /// <exception cref="InvalidOperationException">
-        /// Thrown if <c>href</c> attribute is provided and <see cref="Action"/>, <see cref="Controller"/>,
-        /// <see cref="Fragment"/>, <see cref="Host"/>, <see cref="Protocol"/>, or <see cref="Route"/> are
-        /// non-<c>null</c> or if the user provided <c>asp-route-*</c> attributes. Also thrown if <see cref="Route"/>
-        /// and one or both of <see cref="Action"/> and <see cref="Controller"/> are non-<c>null</c>.
-        /// </exception>
         public override void Process(TagHelperContext context, TagHelperOutput output)
         {
             if (context == null)
@@ -158,6 +171,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                 if (Action != null ||
                     Controller != null ||
                     Area != null ||
+                    Page != null ||
                     Route != null ||
                     Protocol != null ||
                     Host != null ||
@@ -167,7 +181,9 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                     // User specified an href and one of the bound attributes; can't determine the href attribute.
                     throw new InvalidOperationException(
                         Resources.FormatAnchorTagHelper_CannotOverrideHref(
+                            Href,
                             "<a>",
+                            RouteValuesPrefix,
                             ActionAttributeName,
                             ControllerAttributeName,
                             AreaAttributeName,
@@ -175,72 +191,84 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                             ProtocolAttributeName,
                             HostAttributeName,
                             FragmentAttributeName,
-                            RouteValuesPrefix,
+                            PageAttributeName));
-                            Href));
                 }
+
+                return;
+            }
+
+            var routeLink = Route != null;
+            var actionLink = Controller != null || Action != null;
+            var pageLink = Page != null;
+
+            if ((routeLink && actionLink) || (routeLink && pageLink) || (actionLink && pageLink))
+            {
+                var message = string.Join(
+                    Environment.NewLine,
+                    Resources.FormatCannotDetermineAttributeFor(Href, "<a>"),
+                    RouteAttributeName,
+                    ControllerAttributeName + ", " + ActionAttributeName,
+                    PageAttributeName);
+
+                throw new InvalidOperationException(message);
+            }
+
+            RouteValueDictionary routeValues = null;
+            if (_routeValues != null && _routeValues.Count > 0)
+            {
+                routeValues = new RouteValueDictionary(_routeValues);
+            }
+
+            if (Area != null)
+            {
+                // Unconditionally replace any value from asp-route-area.
+                if (routeValues == null)
+                {
+                    routeValues = new RouteValueDictionary();
+                }
+                routeValues["area"] = Area;
+            }
+
+            TagBuilder tagBuilder;
+            if (pageLink)
+            {
+                tagBuilder = Generator.GeneratePageLink(
+                    ViewContext,
+                    linkText: string.Empty,
+                    pageName: Page,
+                    protocol: Protocol,
+                    hostname: Host,
+                    fragment: Fragment,
+                    routeValues: routeValues,
+                    htmlAttributes: null);
+            }
+            else if (routeLink)
+            {
+                tagBuilder = Generator.GenerateRouteLink(
+                    ViewContext,
+                    linkText: string.Empty,
+                    routeName: Route,
+                    protocol: Protocol,
+                    hostName: Host,
+                    fragment: Fragment,
+                    routeValues: routeValues,
+                    htmlAttributes: null);
             }
             else
             {
-                RouteValueDictionary routeValues = null;
+                tagBuilder = Generator.GenerateActionLink(
-                if (_routeValues != null && _routeValues.Count > 0)
+                   ViewContext,
-                {
+                   linkText: string.Empty,
-                    routeValues = new RouteValueDictionary(_routeValues);
+                   actionName: Action,
-                }
+                   controllerName: Controller,
-
+                   protocol: Protocol,
-                if (Area != null)
+                   hostname: Host,
-                {
+                   fragment: Fragment,
-                    if (routeValues == null)
+                   routeValues: routeValues,
-                    {
+                   htmlAttributes: null);
-                        routeValues = new RouteValueDictionary();
-                    }
-
-                    // Unconditionally replace any value from asp-route-area.
-                    routeValues["area"] = Area;
-                }
-
-                TagBuilder tagBuilder;
-                if (Route == null)
-                {
-                    tagBuilder = Generator.GenerateActionLink(
-                        ViewContext,
-                        linkText: string.Empty,
-                        actionName: Action,
-                        controllerName: Controller,
-                        protocol: Protocol,
-                        hostname: Host,
-                        fragment: Fragment,
-                        routeValues: routeValues,
-                        htmlAttributes: null);
-                }
-                else if (Action != null || Controller != null)
-                {
-                    // Route and Action or Controller were specified. Can't determine the href attribute.
-                    throw new InvalidOperationException(
-                        Resources.FormatAnchorTagHelper_CannotDetermineHrefRouteActionOrControllerSpecified(
-                            "<a>",
-                            RouteAttributeName,
-                            ActionAttributeName,
-                            ControllerAttributeName,
-                            Href));
-                }
-                else
-                {
-                    tagBuilder = Generator.GenerateRouteLink(
-                        ViewContext,
-                        linkText: string.Empty,
-                        routeName: Route,
-                        protocol: Protocol,
-                        hostName: Host,
-                        fragment: Fragment,
-                        routeValues: routeValues,
-                        htmlAttributes: null);
-                }
-
-                if (tagBuilder != null)
-                {
-                    output.MergeAttributes(tagBuilder);
-                }
             }
+
+            output.MergeAttributes(tagBuilder);
         }
     }
 }

src/Microsoft.AspNetCore.Mvc.TagHelpers/FormActionTagHelper.cs

@@ -18,6 +18,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
     [HtmlTargetElement("button", Attributes = ActionAttributeName)]
     [HtmlTargetElement("button", Attributes = ControllerAttributeName)]
     [HtmlTargetElement("button", Attributes = AreaAttributeName)]
+    [HtmlTargetElement("button", Attributes = PageAttributeName)]
     [HtmlTargetElement("button", Attributes = FragmentAttributeName)]
     [HtmlTargetElement("button", Attributes = RouteAttributeName)]
     [HtmlTargetElement("button", Attributes = RouteValuesDictionaryName)]
@@ -25,6 +26,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
     [HtmlTargetElement("input", Attributes = ImageActionAttributeSelector, TagStructure = TagStructure.WithoutEndTag)]
     [HtmlTargetElement("input", Attributes = ImageControllerAttributeSelector, TagStructure = TagStructure.WithoutEndTag)]
     [HtmlTargetElement("input", Attributes = ImageAreaAttributeSelector, TagStructure = TagStructure.WithoutEndTag)]
+    [HtmlTargetElement("input", Attributes = ImagePageAttributeSelector, TagStructure = TagStructure.WithoutEndTag)]
     [HtmlTargetElement("input", Attributes = ImageFragmentAttributeSelector, TagStructure = TagStructure.WithoutEndTag)]
     [HtmlTargetElement("input", Attributes = ImageRouteAttributeSelector, TagStructure = TagStructure.WithoutEndTag)]
     [HtmlTargetElement("input", Attributes = ImageRouteValuesDictionarySelector, TagStructure = TagStructure.WithoutEndTag)]
@@ -32,6 +34,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
     [HtmlTargetElement("input", Attributes = SubmitActionAttributeSelector, TagStructure = TagStructure.WithoutEndTag)]
     [HtmlTargetElement("input", Attributes = SubmitControllerAttributeSelector, TagStructure = TagStructure.WithoutEndTag)]
     [HtmlTargetElement("input", Attributes = SubmitAreaAttributeSelector, TagStructure = TagStructure.WithoutEndTag)]
+    [HtmlTargetElement("input", Attributes = SubmitPageAttributeSelector, TagStructure = TagStructure.WithoutEndTag)]
     [HtmlTargetElement("input", Attributes = SubmitFragmentAttributeSelector, TagStructure = TagStructure.WithoutEndTag)]
     [HtmlTargetElement("input", Attributes = SubmitRouteAttributeSelector, TagStructure = TagStructure.WithoutEndTag)]
     [HtmlTargetElement("input", Attributes = SubmitRouteValuesDictionarySelector, TagStructure = TagStructure.WithoutEndTag)]
@@ -41,6 +44,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         private const string ActionAttributeName = "asp-action";
         private const string AreaAttributeName = "asp-area";
         private const string ControllerAttributeName = "asp-controller";
+        private const string PageAttributeName = "asp-page";
         private const string FragmentAttributeName = "asp-fragment";
         private const string RouteAttributeName = "asp-route";
         private const string RouteValuesDictionaryName = "asp-all-route-data";
@@ -50,6 +54,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         private const string ImageTypeSelector = "[type=image], ";
         private const string ImageActionAttributeSelector = ImageTypeSelector + ActionAttributeName;
         private const string ImageAreaAttributeSelector = ImageTypeSelector + AreaAttributeName;
+        private const string ImagePageAttributeSelector = ImageTypeSelector + PageAttributeName;
         private const string ImageFragmentAttributeSelector = ImageTypeSelector + FragmentAttributeName;
         private const string ImageControllerAttributeSelector = ImageTypeSelector + ControllerAttributeName;
         private const string ImageRouteAttributeSelector = ImageTypeSelector + RouteAttributeName;
@@ -59,6 +64,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         private const string SubmitTypeSelector = "[type=submit], ";
         private const string SubmitActionAttributeSelector = SubmitTypeSelector + ActionAttributeName;
         private const string SubmitAreaAttributeSelector = SubmitTypeSelector + AreaAttributeName;
+        private const string SubmitPageAttributeSelector = SubmitTypeSelector + PageAttributeName;
         private const string SubmitFragmentAttributeSelector = SubmitTypeSelector + FragmentAttributeName;
         private const string SubmitControllerAttributeSelector = SubmitTypeSelector + ControllerAttributeName;
         private const string SubmitRouteAttributeSelector = SubmitTypeSelector + RouteAttributeName;
@@ -106,6 +112,12 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         [HtmlAttributeName(AreaAttributeName)]
         public string Area { get; set; }
 
+        /// <summary>
+        /// The name of the page.
+        /// </summary>
+        [HtmlAttributeName(PageAttributeName)]
+        public string Page { get; set; }
+
         /// <summary>
         /// Gets or sets the URL fragment.
         /// </summary>
@@ -185,51 +197,59 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                             RouteValuesPrefix,
                             FormAction));
                 }
+
+                return;
+            }
+
+            var routeLink = Route != null;
+            var actionLink = Controller != null || Action != null;
+            var pageLink = Page != null;
+
+            if ((routeLink && actionLink) || (routeLink && pageLink) || (actionLink && pageLink))
+            {
+                var message = string.Join(
+                    Environment.NewLine,
+                    Resources.FormatCannotDetermineAttributeFor(FormAction, '<' + output.TagName + '>'),
+                    RouteAttributeName,
+                    ControllerAttributeName + ", " + ActionAttributeName,
+                    PageAttributeName);
+
+                throw new InvalidOperationException(message);
+            }
+
+            RouteValueDictionary routeValues = null;
+            if (_routeValues != null && _routeValues.Count > 0)
+            {
+                routeValues = new RouteValueDictionary(_routeValues);
+            }
+
+            if (Area != null)
+            {
+                if (routeValues == null)
+                {
+                    routeValues = new RouteValueDictionary();
+                }
+
+                // Unconditionally replace any value from asp-route-area.
+                routeValues["area"] = Area;
+            }
+
+            var urlHelper = UrlHelperFactory.GetUrlHelper(ViewContext);
+            string url;
+            if (pageLink)
+            {
+                url = urlHelper.Page(Page, routeValues, protocol: null, host: null, fragment: Fragment);
+            }
+            else if (routeLink)
+            {
+                url = urlHelper.RouteUrl(Route, routeValues, protocol: null, host: null, fragment: Fragment);
             }
             else
             {
-                RouteValueDictionary routeValues = null;
+                url = urlHelper.Action(Action, Controller, routeValues, protocol: null, host: null, fragment: Fragment);
-                if (_routeValues != null && _routeValues.Count > 0)
-                {
-                    routeValues = new RouteValueDictionary(_routeValues);
-                }
-
-                if (Area != null)
-                {
-                    if (routeValues == null)
-                    {
-                        routeValues = new RouteValueDictionary();
-                    }
-
-                    // Unconditionally replace any value from asp-route-area.
-                    routeValues["area"] = Area;
-                }
-
-                if (Route == null)
-                {
-                    var urlHelper = UrlHelperFactory.GetUrlHelper(ViewContext);
-                    var url = urlHelper.Action(Action, Controller, routeValues, protocol: null, host: null, fragment: Fragment);
-                    output.Attributes.SetAttribute(FormAction, url);
-                }
-                else if (Action != null || Controller != null)
-                {
-                    // Route and Action or Controller were specified. Can't determine the formaction attribute.
-                    throw new InvalidOperationException(
-                        Resources.FormatFormActionTagHelper_CannotDetermineFormActionRouteActionOrControllerSpecified(
-                            output.TagName,
-                            RouteAttributeName,
-                            ActionAttributeName,
-                            ControllerAttributeName,
-                            FormAction,
-                            FragmentAttributeName));
-                }
-                else
-                {
-                    var urlHelper = UrlHelperFactory.GetUrlHelper(ViewContext);
-                    var url = urlHelper.RouteUrl(Route, routeValues, protocol: null, host: null, fragment: Fragment);
-                    output.Attributes.SetAttribute(FormAction, url);
-                }
             }
+
+            output.Attributes.SetAttribute(FormAction, url);
         }
     }
 }

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

@@ -7,6 +7,7 @@ using System.ComponentModel;
 using Microsoft.AspNetCore.Mvc.Rendering;
 using Microsoft.AspNetCore.Mvc.ViewFeatures;
 using Microsoft.AspNetCore.Razor.TagHelpers;
+using Microsoft.AspNetCore.Routing;
 
 namespace Microsoft.AspNetCore.Mvc.TagHelpers
 {
@@ -16,6 +17,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
     [HtmlTargetElement("form", Attributes = ActionAttributeName)]
     [HtmlTargetElement("form", Attributes = AntiforgeryAttributeName)]
     [HtmlTargetElement("form", Attributes = AreaAttributeName)]
+    [HtmlTargetElement("form", Attributes = PageAttributeName)]
     [HtmlTargetElement("form", Attributes = FragmentAttributeName)]
     [HtmlTargetElement("form", Attributes = ControllerAttributeName)]
     [HtmlTargetElement("form", Attributes = RouteAttributeName)]
@@ -26,6 +28,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         private const string ActionAttributeName = "asp-action";
         private const string AntiforgeryAttributeName = "asp-antiforgery";
         private const string AreaAttributeName = "asp-area";
+        private const string PageAttributeName = "asp-page";
         private const string FragmentAttributeName = "asp-fragment";
         private const string ControllerAttributeName = "asp-controller";
         private const string RouteAttributeName = "asp-route";
@@ -72,6 +75,12 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         [HtmlAttributeName(AreaAttributeName)]
         public string Area { get; set; }
 
+        /// <summary>
+        /// The name of the page.
+        /// </summary>
+        [HtmlAttributeName(PageAttributeName)]
+        public string Page { get; set; }
+
         /// <summary>
         /// Whether the antiforgery token should be generated.
         /// </summary>
@@ -156,6 +165,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                 if (Action != null ||
                     Controller != null ||
                     Area != null ||
+                    Page != null ||
                     Fragment != null ||
                     Route != null ||
                     (_routeValues != null && _routeValues.Count > 0))
@@ -163,14 +173,15 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                     // User also specified bound attributes we cannot use.
                     throw new InvalidOperationException(
                         Resources.FormatFormTagHelper_CannotOverrideAction(
-                            "<form>",
                             HtmlActionAttributeName,
+                            "<form>",
+                            RouteValuesPrefix,
                             ActionAttributeName,
                             ControllerAttributeName,
                             FragmentAttributeName,
                             AreaAttributeName,
                             RouteAttributeName,
-                            RouteValuesPrefix));
+                            PageAttributeName));
                 }
 
                 // User is using the FormTagHelper like a normal <form> tag. Antiforgery default should be false to
@@ -179,22 +190,33 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             }
             else
             {
-                IDictionary<string, object> routeValues = null;
+                var routeLink = Route != null;
+                var actionLink = Controller != null || Action != null;
+                var pageLink = Page != null;
+
+                if ((routeLink && actionLink) || (routeLink && pageLink) || (actionLink && pageLink))
+                {
+                    var message = string.Join(
+                        Environment.NewLine,
+                        Resources.FormatCannotDetermineAttributeFor(HtmlActionAttributeName, "<form>"),
+                        RouteAttributeName,
+                        ControllerAttributeName + ", " + ActionAttributeName,
+                        PageAttributeName);
+
+                    throw new InvalidOperationException(message);
+                }
+
+                RouteValueDictionary routeValues = null;
                 if (_routeValues != null && _routeValues.Count > 0)
                 {
-                    // Convert from Dictionary<string, string> to Dictionary<string, object>.
+                    routeValues = new RouteValueDictionary(_routeValues);
-                    routeValues = new Dictionary<string, object>(_routeValues.Count, StringComparer.OrdinalIgnoreCase);
-                    foreach (var routeValue in _routeValues)
-                    {
-                        routeValues.Add(routeValue.Key, routeValue.Value);
-                    }
                 }
 
                 if (Area != null)
                 {
                     if (routeValues == null)
                     {
-                        routeValues = new Dictionary<string, object>(StringComparer.OrdinalIgnoreCase);
+                        routeValues = new RouteValueDictionary();
                     }
 
                     // Unconditionally replace any value from asp-route-area.
@@ -202,7 +224,27 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                 }
 
                 TagBuilder tagBuilder;
-                if (Route == null)
+                if (pageLink)
+                {
+                    tagBuilder = Generator.GeneratePageForm(
+                        ViewContext,
+                        Page,
+                        routeValues,
+                        Fragment,
+                        method: null,
+                        htmlAttributes: null);
+                }
+                else if (routeLink)
+                {
+                    tagBuilder = Generator.GenerateRouteForm(
+                        ViewContext,
+                        Route,
+                        routeValues,
+                        Fragment,
+                        method: null,
+                        htmlAttributes: null);
+                }
+                else
                 {
                     tagBuilder = Generator.GenerateForm(
                         ViewContext,
@@ -213,42 +255,14 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                         method: null,
                         htmlAttributes: null);
                 }
-                else if (Action != null || Controller != null)
+
+                output.MergeAttributes(tagBuilder);
+                if (tagBuilder.HasInnerHtml)
                 {
-                    // Route and Action or Controller were specified. Can't determine the action attribute.
+                    output.PostContent.AppendHtml(tagBuilder.InnerHtml);
-                    throw new InvalidOperationException(
-                        Resources.FormatFormTagHelper_CannotDetermineActionWithRouteAndActionOrControllerSpecified(
-                            "<form>",
-                            RouteAttributeName,
-                            ActionAttributeName,
-                            ControllerAttributeName,
-                            HtmlActionAttributeName,
-                            FragmentAttributeName));
-                }
-                else
-                {
-                    tagBuilder = Generator.GenerateRouteForm(
-                        ViewContext,
-                        Route,
-                        routeValues,
-                        Fragment,
-                        method: null,
-                        htmlAttributes: null);
                 }
 
-                if (tagBuilder != null)
+                antiforgeryDefault = !string.Equals(Method, "get", StringComparison.OrdinalIgnoreCase);
-                {
-                    output.MergeAttributes(tagBuilder);
-                    if (tagBuilder.HasInnerHtml)
-                    {
-                        output.PostContent.AppendHtml(tagBuilder.InnerHtml);
-                    }
-                }
-
-                if (string.Equals(Method, "get", StringComparison.OrdinalIgnoreCase))
-                {
-                    antiforgeryDefault = false;
-                }
             }
 
             if (Antiforgery ?? antiforgeryDefault)

src/Microsoft.AspNetCore.Mvc.TagHelpers/Properties/Resources.Designer.cs

@@ -11,21 +11,21 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             = new ResourceManager("Microsoft.AspNetCore.Mvc.TagHelpers.Resources", typeof(Resources).GetTypeInfo().Assembly);
 
         /// <summary>
-        /// Cannot determine an '{4}' attribute for {0}. An {0} with a specified '{1}' must not have an '{2}' or '{3}' attribute.
+        /// Cannot determine the '{0}' attribute for {1}. The following attributes are mutually exclusive:
         /// </summary>
-        internal static string AnchorTagHelper_CannotDetermineHrefRouteActionOrControllerSpecified
+        internal static string CannotDetermineAttributeFor
         {
-            get => GetString("AnchorTagHelper_CannotDetermineHrefRouteActionOrControllerSpecified");
+            get => GetString("CannotDetermineAttributeFor");
         }
 
         /// <summary>
-        /// Cannot determine an '{4}' attribute for {0}. An {0} with a specified '{1}' must not have an '{2}' or '{3}' attribute.
+        /// Cannot determine the '{0}' attribute for {1}. The following attributes are mutually exclusive:
         /// </summary>
-        internal static string FormatAnchorTagHelper_CannotDetermineHrefRouteActionOrControllerSpecified(object p0, object p1, object p2, object p3, object p4)
+        internal static string FormatCannotDetermineAttributeFor(object p0, object p1)
-            => string.Format(CultureInfo.CurrentCulture, GetString("AnchorTagHelper_CannotDetermineHrefRouteActionOrControllerSpecified"), p0, p1, p2, p3, p4);
+            => string.Format(CultureInfo.CurrentCulture, GetString("CannotDetermineAttributeFor"), p0, p1);
 
         /// <summary>
-        /// Cannot override the '{9}' attribute for {0}. An {0} with a specified '{9}' must not have attributes starting with '{8}' or an '{1}', '{2}', '{3}', '{4}', '{5}', '{6}', or '{7}' attribute.
+        /// Cannot override the '{0}' attribute for {1}. An {1} with a specified '{0}' must not have attributes starting with '{2}' or an '{3}', '{4}', '{5}', '{6}', '{7}', '{8}', '{9}', or '{10}' attribute.
         /// </summary>
         internal static string AnchorTagHelper_CannotOverrideHref
         {
@@ -33,13 +33,13 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         }
 
         /// <summary>
-        /// Cannot override the '{9}' attribute for {0}. An {0} with a specified '{9}' must not have attributes starting with '{8}' or an '{1}', '{2}', '{3}', '{4}', '{5}', '{6}', or '{7}' attribute.
+        /// Cannot override the '{0}' attribute for {1}. An {1} with a specified '{0}' must not have attributes starting with '{2}' or an '{3}', '{4}', '{5}', '{6}', '{7}', '{8}', '{9}', or '{10}' attribute.
         /// </summary>
-        internal static string FormatAnchorTagHelper_CannotOverrideHref(object p0, object p1, object p2, object p3, object p4, object p5, object p6, object p7, object p8, object p9)
+        internal static string FormatAnchorTagHelper_CannotOverrideHref(object p0, object p1, object p2, object p3, object p4, object p5, object p6, object p7, object p8, object p9, object p10)
-            => string.Format(CultureInfo.CurrentCulture, GetString("AnchorTagHelper_CannotOverrideHref"), p0, p1, p2, p3, p4, p5, p6, p7, p8, p9);
+            => string.Format(CultureInfo.CurrentCulture, GetString("AnchorTagHelper_CannotOverrideHref"), p0, p1, p2, p3, p4, p5, p6, p7, p8, p9, p10);
 
         /// <summary>
-        /// Cannot override the '{1}' attribute for {0}. A {0} with a specified '{1}' must not have attributes starting with '{7}' or an '{2}', '{3}', '{4}', '{5}', or '{6}' attribute.
+        /// Cannot override the '{0}' attribute for {1}. A {1} with a specified '{0}' must not have attributes starting with '{2}' or an '{3}', '{4}', '{5}', '{6}', '{7}' or '{8}' attribute.
         /// </summary>
         internal static string FormTagHelper_CannotOverrideAction
         {
@@ -47,10 +47,10 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         }
 
         /// <summary>
-        /// Cannot override the '{1}' attribute for {0}. A {0} with a specified '{1}' must not have attributes starting with '{7}' or an '{2}', '{3}', '{4}', '{5}', or '{6}' attribute.
+        /// Cannot override the '{0}' attribute for {1}. A {1} with a specified '{0}' must not have attributes starting with '{2}' or an '{3}', '{4}', '{5}', '{6}', '{7}' or '{8}' attribute.
         /// </summary>
-        internal static string FormatFormTagHelper_CannotOverrideAction(object p0, object p1, object p2, object p3, object p4, object p5, object p6, object p7)
+        internal static string FormatFormTagHelper_CannotOverrideAction(object p0, object p1, object p2, object p3, object p4, object p5, object p6, object p7, object p8)
-            => string.Format(CultureInfo.CurrentCulture, GetString("FormTagHelper_CannotOverrideAction"), p0, p1, p2, p3, p4, p5, p6, p7);
+            => string.Format(CultureInfo.CurrentCulture, GetString("FormTagHelper_CannotOverrideAction"), p0, p1, p2, p3, p4, p5, p6, p7, p8);
 
         /// <summary>
         /// Unexpected '{1}' expression result type '{2}' for {0}. '{1}' must be of type '{3}' or '{4}' that can be parsed as a '{3}' if '{5}' is '{6}'.
@@ -136,20 +136,6 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         internal static string FormatTagHelperOutput_AttributeDoesNotExist(object p0, object p1)
             => string.Format(CultureInfo.CurrentCulture, GetString("TagHelperOutput_AttributeDoesNotExist"), p0, p1);
 
-        /// <summary>
-        /// Cannot determine an '{4}' attribute for {0}. A {0} with a specified '{1}' must not have an '{2}', '{3}', or '{5}' attribute.
-        /// </summary>
-        internal static string FormTagHelper_CannotDetermineActionWithRouteAndActionOrControllerSpecified
-        {
-            get => GetString("FormTagHelper_CannotDetermineActionWithRouteAndActionOrControllerSpecified");
-        }
-
-        /// <summary>
-        /// Cannot determine an '{4}' attribute for {0}. A {0} with a specified '{1}' must not have an '{2}', '{3}', or '{5}' attribute.
-        /// </summary>
-        internal static string FormatFormTagHelper_CannotDetermineActionWithRouteAndActionOrControllerSpecified(object p0, object p1, object p2, object p3, object p4, object p5)
-            => string.Format(CultureInfo.CurrentCulture, GetString("FormTagHelper_CannotDetermineActionWithRouteAndActionOrControllerSpecified"), p0, p1, p2, p3, p4, p5);
-
         /// <summary>
         /// The '{0}' property of '{1}' must not be null.
         /// </summary>
@@ -178,20 +164,6 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         internal static string FormatFormActionTagHelper_CannotOverrideFormAction(object p0, object p1, object p2, object p3, object p4, object p5, object p6, object p7)
             => string.Format(CultureInfo.CurrentCulture, GetString("FormActionTagHelper_CannotOverrideFormAction"), p0, p1, p2, p3, p4, p5, p6, p7);
 
-        /// <summary>
-        /// Cannot determine a '{4}' attribute for &lt;{0}&gt;. &lt;{0}&gt; elements with a specified '{1}' must not have an '{2}', '{3}', or '{5}' attribute.
-        /// </summary>
-        internal static string FormActionTagHelper_CannotDetermineFormActionRouteActionOrControllerSpecified
-        {
-            get => GetString("FormActionTagHelper_CannotDetermineFormActionRouteActionOrControllerSpecified");
-        }
-
-        /// <summary>
-        /// Cannot determine a '{4}' attribute for &lt;{0}&gt;. &lt;{0}&gt; elements with a specified '{1}' must not have an '{2}', '{3}', or '{5}' attribute.
-        /// </summary>
-        internal static string FormatFormActionTagHelper_CannotDetermineFormActionRouteActionOrControllerSpecified(object p0, object p1, object p2, object p3, object p4, object p5)
-            => string.Format(CultureInfo.CurrentCulture, GetString("FormActionTagHelper_CannotDetermineFormActionRouteActionOrControllerSpecified"), p0, p1, p2, p3, p4, p5);
-
         private static string GetString(string name, params string[] formatterNames)
         {
             var value = _resourceManager.GetString(name);

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

@@ -117,14 +117,14 @@
   <resheader name="writer">
     <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
   </resheader>
-  <data name="AnchorTagHelper_CannotDetermineHrefRouteActionOrControllerSpecified" xml:space="preserve">
+  <data name="CannotDetermineAttributeFor" xml:space="preserve">
-    <value>Cannot determine an '{4}' attribute for {0}. An {0} with a specified '{1}' must not have an '{2}' or '{3}' attribute.</value>
+    <value>Cannot determine the '{0}' attribute for {1}. The following attributes are mutually exclusive:</value>
   </data>
   <data name="AnchorTagHelper_CannotOverrideHref" xml:space="preserve">
-    <value>Cannot override the '{9}' attribute for {0}. An {0} with a specified '{9}' must not have attributes starting with '{8}' or an '{1}', '{2}', '{3}', '{4}', '{5}', '{6}', or '{7}' attribute.</value>
+    <value>Cannot override the '{0}' attribute for {1}. An {1} with a specified '{0}' must not have attributes starting with '{2}' or an '{3}', '{4}', '{5}', '{6}', '{7}', '{8}', '{9}', or '{10}' attribute.</value>
   </data>
   <data name="FormTagHelper_CannotOverrideAction" xml:space="preserve">
-    <value>Cannot override the '{1}' attribute for {0}. A {0} with a specified '{1}' must not have attributes starting with '{7}' or an '{2}', '{3}', '{4}', '{5}', or '{6}' attribute.</value>
+    <value>Cannot override the '{0}' attribute for {1}. A {1} with a specified '{0}' must not have attributes starting with '{2}' or an '{3}', '{4}', '{5}', '{6}', '{7}' or '{8}' attribute.</value>
   </data>
   <data name="InputTagHelper_InvalidExpressionResult" xml:space="preserve">
     <value>Unexpected '{1}' expression result type '{2}' for {0}. '{1}' must be of type '{3}' or '{4}' that can be parsed as a '{3}' if '{5}' is '{6}'.</value>
@@ -144,16 +144,10 @@
   <data name="TagHelperOutput_AttributeDoesNotExist" xml:space="preserve">
     <value>The attribute '{0}' does not exist in the {1}.</value>
   </data>
-  <data name="FormTagHelper_CannotDetermineActionWithRouteAndActionOrControllerSpecified" xml:space="preserve">
-    <value>Cannot determine an '{4}' attribute for {0}. A {0} with a specified '{1}' must not have an '{2}', '{3}', or '{5}' attribute.</value>
-  </data>
   <data name="PropertyOfTypeCannotBeNull" xml:space="preserve">
     <value>The '{0}' property of '{1}' must not be null.</value>
   </data>
   <data name="FormActionTagHelper_CannotOverrideFormAction" xml:space="preserve">
     <value>Cannot override the '{7}' attribute for &lt;{0}&gt;. &lt;{0}&gt; elements with a specified '{7}' must not have attributes starting with '{6}' or an '{1}', '{2}', '{3}', '{4}', or '{5}' attribute.</value>
   </data>
-  <data name="FormActionTagHelper_CannotDetermineFormActionRouteActionOrControllerSpecified" xml:space="preserve">
-    <value>Cannot determine a '{4}' attribute for &lt;{0}&gt;. &lt;{0}&gt; elements with a specified '{1}' must not have an '{2}', '{3}', or '{5}' attribute.</value>
-  </data>
 </root>

src/Microsoft.AspNetCore.Mvc.ViewFeatures/ViewFeatures/DefaultHtmlGenerator.cs

@@ -142,6 +142,32 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures
             return GenerateLink(linkText, url, htmlAttributes);
         }
 
+        /// <inheritdoc />
+        public virtual TagBuilder GeneratePageLink(
+            ViewContext viewContext,
+            string linkText,
+            string pageName,
+            string protocol,
+            string hostname,
+            string fragment,
+            object routeValues,
+            object htmlAttributes)
+        {
+            if (viewContext == null)
+            {
+                throw new ArgumentNullException(nameof(viewContext));
+            }
+
+            if (linkText == null)
+            {
+                throw new ArgumentNullException(nameof(linkText));
+            }
+
+            var urlHelper = _urlHelperFactory.GetUrlHelper(viewContext);
+            var url = urlHelper.Page(pageName, routeValues, protocol, hostname, fragment);
+            return GenerateLink(linkText, url, htmlAttributes);
+        }
+
         /// <inheritdoc />
         public virtual IHtmlContent GenerateAntiforgery(ViewContext viewContext)
         {
@@ -281,6 +307,52 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures
             return GenerateFormCore(viewContext, action, method, htmlAttributes);
         }
 
+        /// <inheritdoc />
+        public virtual TagBuilder GeneratePageForm(
+            ViewContext viewContext,
+            string pageName,
+            object routeValues,
+            string fragment,
+            string method,
+            object htmlAttributes)
+        {
+            if (viewContext == null)
+            {
+                throw new ArgumentNullException(nameof(viewContext));
+            }
+
+            var defaultMethod = false;
+            if (string.IsNullOrEmpty(method))
+            {
+                defaultMethod = true;
+            }
+            else if (string.Equals(method, "post", StringComparison.OrdinalIgnoreCase))
+            {
+                defaultMethod = true;
+            }
+
+            string action;
+            if (pageName == null && routeValues == null && defaultMethod)
+            {
+                // Submit to the original URL in the special case that user called the BeginForm() overload without
+                // parameters (except for the htmlAttributes parameter). Also reachable in the even-more-unusual case
+                // that user called another BeginForm() overload with default argument values.
+                var request = viewContext.HttpContext.Request;
+                action = request.PathBase + request.Path + request.QueryString;
+                if (fragment != null)
+                {
+                    action += "#" + fragment;
+                }
+            }
+            else
+            {
+                var urlHelper = _urlHelperFactory.GetUrlHelper(viewContext);
+                action = urlHelper.Page(pageName, values: routeValues,protocol: null, host: null, fragment: fragment);
+            }
+
+            return GenerateFormCore(viewContext, action, method, htmlAttributes);
+        }
+
         /// <inheritdoc />
         public TagBuilder GenerateRouteForm(
             ViewContext viewContext,

src/Microsoft.AspNetCore.Mvc.ViewFeatures/ViewFeatures/DefaultHtmlGeneratorExtensions.cs

@@ -1,6 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
 using Microsoft.AspNetCore.Mvc.Rendering;
 
 namespace Microsoft.AspNetCore.Mvc.ViewFeatures

src/Microsoft.AspNetCore.Mvc.ViewFeatures/ViewFeatures/IHtmlGenerator.cs

@@ -54,6 +54,38 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures
             object routeValues,
             object htmlAttributes);
 
+        /// <summary>
+        /// Generate a &lt;a&gt; element for a link to an action.
+        /// </summary>
+        /// <param name="viewContext">The <see cref="ViewContext"/> instance for the current scope.</param>
+        /// <param name="linkText">The text to insert inside the element.</param>
+        /// <param name="pageName">The page name.</param>
+        /// <param name="protocol">The protocol (scheme) for the generated link.</param>
+        /// <param name="hostname">The hostname for the generated link.</param>
+        /// <param name="fragment">The fragment for the genrated link.</param>
+        /// <param name="routeValues">
+        /// An <see cref="object"/> that contains the parameters for a route. The parameters are retrieved through
+        /// reflection by examining the properties of the <see cref="object"/>. This <see cref="object"/> is typically
+        /// created using <see cref="object"/> initializer syntax. Alternatively, an
+        /// <see cref="IDictionary{String, Object}"/> instance containing the route parameters.
+        /// </param>
+        /// <param name="htmlAttributes">
+        /// An <see cref="object"/> that contains the HTML attributes for the element. Alternatively, an
+        /// <see cref="IDictionary{String, Object}"/> instance containing the HTML attributes.
+        /// </param>
+        /// <returns>
+        /// A <see cref="TagBuilder"/> instance for the &lt;a&gt; element.
+        /// </returns>
+        TagBuilder GeneratePageLink(
+            ViewContext viewContext,
+            string linkText,
+            string pageName,
+            string protocol,
+            string hostname,
+            string fragment,
+            object routeValues,
+            object htmlAttributes);
+
         /// <summary>
         /// Generate an &lt;input type="hidden".../&gt; element containing an antiforgery token.
         /// </summary>
@@ -124,6 +156,35 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures
             string method,
             object htmlAttributes);
 
+        /// <summary>
+        /// Generate a &lt;form&gt; element. When the user submits the form, the page with name
+        /// <paramref name="pageName"/> will process the request.
+        /// </summary>
+        /// <param name="viewContext">A <see cref="ViewContext"/> instance for the current scope.</param>
+        /// <param name="pageName">The name of the action method.</param>
+        /// <param name="routeValues">
+        /// An <see cref="object"/> that contains the parameters for a route. The parameters are retrieved through
+        /// reflection by examining the properties of the <see cref="object"/>. This <see cref="object"/> is typically
+        /// created using <see cref="object"/> initializer syntax. Alternatively, an
+        /// <see cref="IDictionary{String, Object}"/> instance containing the route parameters.
+        /// </param>
+        /// <param name="fragment">The url fragment.</param>
+        /// <param name="method">The HTTP method for processing the form, either GET or POST.</param>
+        /// <param name="htmlAttributes">
+        /// An <see cref="object"/> that contains the HTML attributes for the element. Alternatively, an
+        /// <see cref="IDictionary{String, Object}"/> instance containing the HTML attributes.
+        /// </param>
+        /// <returns>
+        /// A <see cref="TagBuilder"/> instance for the &lt;/form&gt; element.
+        /// </returns>
+        TagBuilder GeneratePageForm(
+            ViewContext viewContext,
+            string pageName,
+            object routeValues,
+            string fragment,
+            string method,
+            object htmlAttributes);
+
         /// <summary>
         /// Generate a &lt;form&gt; element. The route with name <paramref name="routeName"/> generates the
         /// &lt;form&gt;'s <c>action</c> attribute value.

test/Microsoft.AspNetCore.Mvc.Core.Test/RedirectToPageResultTest.cs

@@ -33,7 +33,7 @@ namespace Microsoft.AspNetCore.Mvc
             var actionContext = new ActionContext(httpContext, new RouteData(), new ActionDescriptor());
 
             var urlHelper = GetUrlHelper(actionContext, returnValue: null);
-            var result = new RedirectToPageResult("some-page", new Dictionary<string, object>())
+            var result = new RedirectToPageResult("/some-page", new Dictionary<string, object>())
             {
                 UrlHelper = urlHelper,
             };
@@ -41,7 +41,7 @@ namespace Microsoft.AspNetCore.Mvc
             // Act & Assert
             await ExceptionAssert.ThrowsAsync<InvalidOperationException>(
                 () => result.ExecuteResultAsync(actionContext),
-                "No page named 'some-page' matches the supplied values.");
+                "No page named '/some-page' matches the supplied values.");
         }
 
         [Theory]
@@ -65,7 +65,7 @@ namespace Microsoft.AspNetCore.Mvc
                 new ActionDescriptor());
 
             var urlHelper = GetUrlHelper(actionContext, expectedUrl);
-            var result = new RedirectToPageResult("MyPage", new { id = 10, test = "value" }, permanentRedirect)
+            var result = new RedirectToPageResult("/MyPage", new { id = 10, test = "value" }, permanentRedirect)
             {
                 UrlHelper = urlHelper,
             };
@@ -99,7 +99,7 @@ namespace Microsoft.AspNetCore.Mvc
                 .Callback((UrlRouteContext c) => context = c)
                 .Returns("some-value");
             var values = new { test = "test-value" };
-            var result = new RedirectToPageResult("MyPage", values, true, "test-fragment")
+            var result = new RedirectToPageResult("/MyPage", values, true, "test-fragment")
             {
                 UrlHelper = urlHelper.Object,
                 Protocol = "ftp",
@@ -120,7 +120,7 @@ namespace Microsoft.AspNetCore.Mvc
                 value =>
                 {
                     Assert.Equal("page", value.Key);
-                    Assert.Equal("MyPage", value.Value);
+                    Assert.Equal("/MyPage", value.Value);
                 });
             Assert.Equal("ftp", context.Protocol);
             Assert.Equal("test-fragment", context.Fragment);

test/Microsoft.AspNetCore.Mvc.FunctionalTests/RazorPagesTest.cs

@@ -903,6 +903,54 @@ Microsoft.AspNetCore.Mvc.ViewFeatures.ViewDataDictionary`1[AspNetCore._InjectedP
             Assert.Equal(expected, response.Headers.Location.ToString());
         }
 
+        [Fact]
+        public async Task TagHelpers_SupportSiblingRoutes()
+        {
+            // Arrange
+var expected = 
+@"<form method=""post"" action=""/Pages/TagHelper/CrossPost""></form>
+<a href=""/Pages/TagHelper/SelfPost/12"" />
+<input type=""image"" formaction=""/Pages/TagHelper/CrossPost#my-fragment"" />";
+
+            // Act
+            var response = await Client.GetStringAsync("/Pages/TagHelper/SiblingLinks");
+
+            // Assert
+            Assert.Equal(expected, response.Trim());
+        }
+
+        [Fact]
+        public async Task TagHelpers_SupportSubDirectoryRoutes()
+        {
+            // Arrange
+var expected = 
+@"<form method=""post"" action=""/Pages/TagHelper/SubDir/SubDirPage""></form>
+<a href=""/Pages/TagHelper/SubDir/SubDirPage/12"" />
+<input type=""image"" formaction=""/Pages/TagHelper/SubDir/SubDirPage#my-fragment"" />";
+
+            // Act
+            var response = await Client.GetStringAsync("/Pages/TagHelper/SubDirectoryLinks");
+
+            // Assert
+            Assert.Equal(expected, response.Trim());
+        }
+
+        [Fact]
+        public async Task TagHelpers_SupportsPathNavigation()
+        {
+            // Arrange
+var expected = 
+@"<form method=""post"" action=""/HelloWorld""></form>
+<a href=""/Pages/Redirects/RedirectToIndex"" />
+<input type=""image"" formaction=""/Pages/Admin#my-fragment"" />";
+
+            // Act
+            var response = await Client.GetStringAsync("/Pages/TagHelper/PathTraversalLinks");
+
+            // Assert
+            Assert.Equal(expected, response.Trim());
+        }
+
         private async Task AddAntiforgeryHeaders(HttpRequestMessage request)
         {
             var getResponse = await Client.GetAsync(request.RequestUri);

test/Microsoft.AspNetCore.Mvc.FunctionalTests/RazorPagesWithBasePathTest.cs

@@ -143,6 +143,48 @@ namespace Microsoft.AspNetCore.Mvc.FunctionalTests
             Assert.Equal(expected, response.Trim());
         }
 
+        [Fact]
+        public async Task FormTagHelper_WithPage_GeneratesLinksToSelf()
+        {
+            //Arrange
+            var expected = "<form method=\"POST\" action=\"/TagHelper/SelfPost/10\">";
+
+            // Act
+            var response = await Client.GetStringAsync("/TagHelper/SelfPost");
+
+            // Assert
+            Assert.Contains(expected, response.Trim());
+        }
+
+        [Fact]
+        public async Task FormTagHelper_WithPage_AllowsPostingToAnotherPage()
+        {
+            //Arrange
+            var expected = "<form method=\"POST\" action=\"/TagHelper/SelfPost/10\">";
+
+            // Act
+            var response = await Client.GetStringAsync("/TagHelper/CrossPost");
+
+            // Assert
+            Assert.Contains(expected, response.Trim());
+        }
+
+        [Fact]
+        public async Task FormActionTagHelper_WithPage_AllowsPostingToAnotherPage()
+        {
+            //Arrange
+            var expected = 
+@"<button formaction=""/TagHelper/CrossPost/10"" />
+<input type=""submit"" formaction=""/TagHelper/CrossPost/10"" />
+<input type=""image"" formaction=""/TagHelper/CrossPost/10"" />";
+
+            // Act
+            var response = await Client.GetStringAsync("/TagHelper/FormAction");
+
+            // Assert
+            Assert.Equal(expected, response.Trim());
+        }
+
         [Fact]
         public async Task RedirectFromPage_RedirectsToPathWithoutIndexSegment()
         {
@@ -170,5 +212,18 @@ namespace Microsoft.AspNetCore.Mvc.FunctionalTests
             Assert.Equal(HttpStatusCode.Redirect, response.StatusCode);
             Assert.Equal(expected, response.Headers.Location.ToString());
         }
+
+        [Fact]
+        public async Task PageRoute_UsingDefaultPageNameToRoute()
+        {
+            // Arrange
+            var expected = @"<a href=""/Routes/Sibling/10"">Link</a>";
+
+            // Act
+            var response = await Client.GetStringAsync("/Routes/RouteUsingDefaultName");
+
+            // Assert
+            Assert.Equal(expected, response.Trim());
+        }
     }
 }

test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/AnchorTagHelperTest.cs

@@ -4,13 +4,13 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Reflection;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Mvc.ModelBinding;
 using Microsoft.AspNetCore.Mvc.Rendering;
 using Microsoft.AspNetCore.Mvc.Routing;
 using Microsoft.AspNetCore.Mvc.ViewFeatures;
 using Microsoft.AspNetCore.Razor.TagHelpers;
+using Microsoft.AspNetCore.Routing;
 using Moq;
 using Xunit;
 
@@ -366,6 +366,55 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             Assert.Empty(output.Content.GetContent());
         }
 
+        [Fact]
+        public async Task ProcessAsync_AddsPageToRouteValuesAndCallsPageLinkWithExpectedParameters()
+        {
+            // Arrange
+            var context = new TagHelperContext(
+                tagName: "a",
+                allAttributes: new TagHelperAttributeList(
+                    Enumerable.Empty<TagHelperAttribute>()),
+                items: new Dictionary<object, object>(),
+                uniqueId: "test");
+            var output = new TagHelperOutput(
+                "a",
+                attributes: new TagHelperAttributeList(),
+                getChildContentAsync: (useCachedResult, encoder) =>
+                {
+                    var tagHelperContent = new DefaultTagHelperContent();
+                    tagHelperContent.SetContent("Something");
+                    return Task.FromResult<TagHelperContent>(tagHelperContent);
+                });
+            output.Content.SetContent(string.Empty);
+
+            var generator = new Mock<IHtmlGenerator>();
+            generator
+                .Setup(mock => mock.GeneratePageLink(
+                    It.IsAny<ViewContext>(),
+                    string.Empty,
+                    "/User/Home/Index",
+                    "http",
+                    "contoso.com",
+                    "hello=world",
+                    It.IsAny<object>(),
+                    null))
+                .Returns(new TagBuilder("a"))
+                .Verifiable();
+            var anchorTagHelper = new AnchorTagHelper(generator.Object)
+            {
+                Page = "/User/Home/Index",
+                Fragment = "hello=world",
+                Host = "contoso.com",
+                Protocol = "http",
+            };
+
+            // Act
+            await anchorTagHelper.ProcessAsync(context, output);
+
+            // Assert
+            generator.Verify();
+        }
+
         [Theory]
         [InlineData("Action")]
         [InlineData("Controller")]
@@ -374,6 +423,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         [InlineData("Host")]
         [InlineData("Fragment")]
         [InlineData("asp-route-")]
+        [InlineData("Page")]
         public async Task ProcessAsync_ThrowsIfHrefConflictsWithBoundAttributes(string propertyName)
         {
             // Arrange
@@ -399,9 +449,9 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             }
 
             var expectedErrorMessage = "Cannot override the 'href' attribute for <a>. An <a> with a specified " +
-                                       "'href' must not have attributes starting with 'asp-route-' or an " +
+                "'href' must not have attributes starting with 'asp-route-' or an " +
-                                       "'asp-action', 'asp-controller', 'asp-area', 'asp-route', 'asp-protocol', 'asp-host', or " +
+                "'asp-action', 'asp-controller', 'asp-area', 'asp-route', 'asp-protocol', 'asp-host', " +
-                                       "'asp-fragment' attribute.";
+                "'asp-fragment', or 'asp-page' attribute.";
 
             var context = new TagHelperContext(
                 tagName: "test",
@@ -436,8 +486,88 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                 "a",
                 attributes: new TagHelperAttributeList(),
                 getChildContentAsync: (useCachedResult, encoder) => Task.FromResult<TagHelperContent>(null));
-            var expectedErrorMessage = "Cannot determine an 'href' attribute for <a>. An <a> with a specified " +
+            var expectedErrorMessage = string.Join(
-                "'asp-route' must not have an 'asp-action' or 'asp-controller' attribute.";
+                Environment.NewLine,
+                "Cannot determine the 'href' attribute for <a>. The following attributes are mutually exclusive:",
+                "asp-route",
+                "asp-controller, asp-action",
+                "asp-page");
+
+            var context = new TagHelperContext(
+                tagName: "test",
+                allAttributes: new TagHelperAttributeList(
+                    Enumerable.Empty<TagHelperAttribute>()),
+                items: new Dictionary<object, object>(),
+                uniqueId: "test");
+
+            // Act & Assert
+            var ex = await Assert.ThrowsAsync<InvalidOperationException>(
+                () => anchorTagHelper.ProcessAsync(context, output));
+
+            Assert.Equal(expectedErrorMessage, ex.Message);
+        }
+
+        [Fact]
+        public async Task ProcessAsync_ThrowsIfRouteAndPageProvided()
+        {
+            // Arrange
+            var metadataProvider = new EmptyModelMetadataProvider();
+            var htmlGenerator = new TestableHtmlGenerator(metadataProvider);
+
+            var anchorTagHelper = new AnchorTagHelper(htmlGenerator)
+            {
+                Route = "Default",
+                Page = "Page",
+            };
+
+            var output = new TagHelperOutput(
+                "a",
+                attributes: new TagHelperAttributeList(),
+                getChildContentAsync: (useCachedResult, encoder) => Task.FromResult<TagHelperContent>(null));
+            var expectedErrorMessage = string.Join(
+                Environment.NewLine,
+                "Cannot determine the 'href' attribute for <a>. The following attributes are mutually exclusive:",
+                "asp-route",
+                "asp-controller, asp-action",
+                "asp-page");
+
+            var context = new TagHelperContext(
+                tagName: "test",
+                allAttributes: new TagHelperAttributeList(
+                    Enumerable.Empty<TagHelperAttribute>()),
+                items: new Dictionary<object, object>(),
+                uniqueId: "test");
+
+            // Act & Assert
+            var ex = await Assert.ThrowsAsync<InvalidOperationException>(
+                () => anchorTagHelper.ProcessAsync(context, output));
+
+            Assert.Equal(expectedErrorMessage, ex.Message);
+        }
+
+        [Fact]
+        public async Task ProcessAsync_ThrowsIfActionAndPageProvided()
+        {
+            // Arrange
+            var metadataProvider = new EmptyModelMetadataProvider();
+            var htmlGenerator = new TestableHtmlGenerator(metadataProvider);
+
+            var anchorTagHelper = new AnchorTagHelper(htmlGenerator)
+            {
+                Action = "Action",
+                Page = "Page",
+            };
+
+            var output = new TagHelperOutput(
+                "a",
+                attributes: new TagHelperAttributeList(),
+                getChildContentAsync: (useCachedResult, encoder) => Task.FromResult<TagHelperContent>(null));
+            var expectedErrorMessage = string.Join(
+                Environment.NewLine,
+                "Cannot determine the 'href' attribute for <a>. The following attributes are mutually exclusive:",
+                "asp-route",
+                "asp-controller, asp-action",
+                "asp-page");
 
             var context = new TagHelperContext(
                 tagName: "test",

test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/FormActionTagHelperTest.cs

@@ -510,8 +510,88 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                 tagName,
                 attributes: new TagHelperAttributeList(),
                 getChildContentAsync: (useCachedResult, encoder) => Task.FromResult<TagHelperContent>(null));
-            var expectedErrorMessage = $"Cannot determine a 'formaction' attribute for <{tagName}>. <{tagName}> " +
+            var expectedErrorMessage = string.Join(
-                "elements with a specified 'asp-route' must not have an 'asp-action', 'asp-controller', or 'asp-fragment' attribute.";
+                Environment.NewLine,
+                $"Cannot determine the 'formaction' attribute for <{tagName}>. The following attributes are mutually exclusive:",
+                "asp-route",
+                "asp-controller, asp-action",
+                "asp-page");
+
+            var context = new TagHelperContext(
+                tagName: "form-action",
+                allAttributes: new TagHelperAttributeList(
+                    Enumerable.Empty<TagHelperAttribute>()),
+                items: new Dictionary<object, object>(),
+                uniqueId: "test");
+
+            // Act & Assert
+            var ex = await Assert.ThrowsAsync<InvalidOperationException>(() => tagHelper.ProcessAsync(context, output));
+
+            Assert.Equal(expectedErrorMessage, ex.Message);
+        }
+
+        [Theory]
+        [InlineData("button")]
+        [InlineData("submit")]
+        public async Task ProcessAsync_ThrowsIfRouteAndPageProvided(string tagName)
+        {
+            // Arrange
+            var urlHelperFactory = new Mock<IUrlHelperFactory>().Object;
+
+            var tagHelper = new FormActionTagHelper(urlHelperFactory)
+            {
+                Route = "Default",
+                Page = "Page",
+            };
+
+            var output = new TagHelperOutput(
+                tagName,
+                attributes: new TagHelperAttributeList(),
+                getChildContentAsync: (useCachedResult, encoder) => Task.FromResult<TagHelperContent>(null));
+            var expectedErrorMessage = string.Join(
+                Environment.NewLine,
+                $"Cannot determine the 'formaction' attribute for <{tagName}>. The following attributes are mutually exclusive:",
+                "asp-route",
+                "asp-controller, asp-action",
+                "asp-page");
+
+            var context = new TagHelperContext(
+                tagName: "form-action",
+                allAttributes: new TagHelperAttributeList(
+                    Enumerable.Empty<TagHelperAttribute>()),
+                items: new Dictionary<object, object>(),
+                uniqueId: "test");
+
+            // Act & Assert
+            var ex = await Assert.ThrowsAsync<InvalidOperationException>(() => tagHelper.ProcessAsync(context, output));
+
+            Assert.Equal(expectedErrorMessage, ex.Message);
+        }
+
+        [Theory]
+        [InlineData("button")]
+        [InlineData("submit")]
+        public async Task ProcessAsync_ThrowsIfActionAndPageProvided(string tagName)
+        {
+            // Arrange
+            var urlHelperFactory = new Mock<IUrlHelperFactory>().Object;
+
+            var tagHelper = new FormActionTagHelper(urlHelperFactory)
+            {
+                Action = "Default",
+                Page = "Page",
+            };
+
+            var output = new TagHelperOutput(
+                tagName,
+                attributes: new TagHelperAttributeList(),
+                getChildContentAsync: (useCachedResult, encoder) => Task.FromResult<TagHelperContent>(null));
+            var expectedErrorMessage = string.Join(
+                Environment.NewLine,
+                $"Cannot determine the 'formaction' attribute for <{tagName}>. The following attributes are mutually exclusive:",
+                "asp-route",
+                "asp-controller, asp-action",
+                "asp-page");
 
             var context = new TagHelperContext(
                 tagName: "form-action",

test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/FormTagHelperTest.cs

@@ -5,7 +5,6 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using System.Reflection;
 using System.Text.Encodings.Web;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Html;
@@ -201,8 +200,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                         // Fixes Roslyn bug with lambdas
                         generator.ToString();
 
-                        var routeValueDictionary = (Dictionary<string, object>)routeValues;
+                        var routeValueDictionary = Assert.IsType<RouteValueDictionary>(routeValues);
-
                         Assert.Equal(2, routeValueDictionary.Count);
                         var routeValue = Assert.Single(routeValueDictionary, attr => attr.Key.Equals("val"));
                         Assert.Equal("hello", routeValue.Value);
@@ -552,7 +550,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                 .Setup(mock => mock.GenerateRouteForm(
                     viewContext,
                     "Default",
-                    It.Is<Dictionary<string, object>>(m => string.Equals(m["name"], "value")),
+                    It.Is<RouteValueDictionary>(m => string.Equals(m["name"], "value")),
                     null,
                     null))
                 .Returns(new TagBuilder("form"))
@@ -582,6 +580,50 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             Assert.Empty(output.PostElement.GetContent());
         }
 
+        [Fact]
+        public async Task ProcessAsync_InvokesGeneratePageForm()
+        {
+            // Arrange
+            var viewContext = CreateViewContext();
+            var context = new TagHelperContext(
+                tagName: "form",
+                allAttributes: new TagHelperAttributeList(
+                    Enumerable.Empty<TagHelperAttribute>()),
+                items: new Dictionary<object, object>(),
+                uniqueId: "test");
+            var output = new TagHelperOutput(
+                "form",
+                attributes: new TagHelperAttributeList(),
+                getChildContentAsync: (useCachedResult, encoder) =>
+                {
+                    var tagHelperContent = new DefaultTagHelperContent();
+                    tagHelperContent.SetContent("Something");
+                    return Task.FromResult<TagHelperContent>(tagHelperContent);
+                });
+            var generator = new Mock<IHtmlGenerator>(MockBehavior.Strict);
+            generator
+                .Setup(mock => mock.GeneratePageForm(
+                    viewContext,
+                    "/Home/Admin/Post",
+                    null,
+                    "hello-world",
+                    null,
+                    null))
+                .Returns(new TagBuilder("form"))
+                .Verifiable();
+            var formTagHelper = new FormTagHelper(generator.Object)
+            {
+                Antiforgery = false,
+                ViewContext = viewContext,
+                Page = "/Home/Admin/Post",
+                Fragment = "hello-world",
+            };
+
+            // Act & Assert
+            await formTagHelper.ProcessAsync(context, output);
+            generator.Verify();
+        }
+
         [Theory]
         [InlineData(true, "<input />")]
         [InlineData(false, "")]
@@ -638,6 +680,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         [Theory]
         [InlineData("Action")]
         [InlineData("Controller")]
+        [InlineData("Page")]
         [InlineData("asp-route-")]
         public async Task ProcessAsync_ThrowsIfActionConflictsWithBoundAttributes(string propertyName)
         {
@@ -660,8 +703,8 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             }
 
             var expectedErrorMessage = "Cannot override the 'action' attribute for <form>. A <form> with a specified " +
-                                       "'action' must not have attributes starting with 'asp-route-' or an " +
+                "'action' must not have attributes starting with 'asp-route-' or an " +
-                                       "'asp-action', 'asp-controller', 'asp-fragment', 'asp-area', or 'asp-route' attribute.";
+                "'asp-action', 'asp-controller', 'asp-fragment', 'asp-area', 'asp-route' or 'asp-page' attribute.";
 
             var context = new TagHelperContext(
                 tagName: "form",
@@ -692,8 +735,80 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                 "form",
                 attributes: new TagHelperAttributeList(),
                 getChildContentAsync: (useCachedResult, encoder) => Task.FromResult<TagHelperContent>(null));
-            var expectedErrorMessage = "Cannot determine an 'action' attribute for <form>. A <form> with a specified " +
+            var expectedErrorMessage = string.Join(
-                "'asp-route' must not have an 'asp-action', 'asp-controller', or 'asp-fragment' attribute.";
+                Environment.NewLine,
+                "Cannot determine the 'action' attribute for <form>. The following attributes are mutually exclusive:",
+                "asp-route",
+                "asp-controller, asp-action",
+                "asp-page");
+
+            var context = new TagHelperContext(
+                tagName: "form",
+                allAttributes: new TagHelperAttributeList(
+                    Enumerable.Empty<TagHelperAttribute>()),
+                items: new Dictionary<object, object>(),
+                uniqueId: "test");
+
+            // Act & Assert
+            var ex = await Assert.ThrowsAsync<InvalidOperationException>(
+                () => formTagHelper.ProcessAsync(context, output));
+
+            Assert.Equal(expectedErrorMessage, ex.Message);
+        }
+
+        [Fact]
+        public async Task ProcessAsync_ThrowsIfRouteAndPageProvided()
+        {
+            // Arrange
+            var formTagHelper = new FormTagHelper(new TestableHtmlGenerator(new EmptyModelMetadataProvider()))
+            {
+                Route = "Default",
+                Page = "Page",
+            };
+            var output = new TagHelperOutput(
+                "form",
+                attributes: new TagHelperAttributeList(),
+                getChildContentAsync: (useCachedResult, encoder) => Task.FromResult<TagHelperContent>(null));
+            var expectedErrorMessage = string.Join(
+                Environment.NewLine,
+                "Cannot determine the 'action' attribute for <form>. The following attributes are mutually exclusive:",
+                "asp-route",
+                "asp-controller, asp-action",
+                "asp-page");
+
+            var context = new TagHelperContext(
+                tagName: "form",
+                allAttributes: new TagHelperAttributeList(
+                    Enumerable.Empty<TagHelperAttribute>()),
+                items: new Dictionary<object, object>(),
+                uniqueId: "test");
+
+            // Act & Assert
+            var ex = await Assert.ThrowsAsync<InvalidOperationException>(
+                () => formTagHelper.ProcessAsync(context, output));
+
+            Assert.Equal(expectedErrorMessage, ex.Message);
+        }
+
+        [Fact]
+        public async Task ProcessAsync_ThrowsIfActionAndPageProvided()
+        {
+            // Arrange
+            var formTagHelper = new FormTagHelper(new TestableHtmlGenerator(new EmptyModelMetadataProvider()))
+            {
+                Action = "Default",
+                Page = "Page",
+            };
+            var output = new TagHelperOutput(
+                "form",
+                attributes: new TagHelperAttributeList(),
+                getChildContentAsync: (useCachedResult, encoder) => Task.FromResult<TagHelperContent>(null));
+            var expectedErrorMessage = string.Join(
+                Environment.NewLine,
+                "Cannot determine the 'action' attribute for <form>. The following attributes are mutually exclusive:",
+                "asp-route",
+                "asp-controller, asp-action",
+                "asp-page");
 
             var context = new TagHelperContext(
                 tagName: "form",

test/WebSites/RazorPagesWebSite/Pages/Routes/RouteUsingDefaultName.cshtml

@@ -0,0 +1,2 @@
+@page
+<a asp-page="/Routes/Sibling" asp-route-id="10">Link</a>

test/WebSites/RazorPagesWebSite/Pages/Routes/Sibling.cshtml

@@ -0,0 +1 @@
+@page "{id?}"

test/WebSites/RazorPagesWebSite/Pages/Routes/_ViewImports.cshtml

@@ -0,0 +1 @@
+@addTagHelper "*, Microsoft.AspNetCore.Mvc.TagHelpers"

test/WebSites/RazorPagesWebSite/Pages/TagHelper/CrossPost.cshtml

@@ -0,0 +1,5 @@
+@page "{id:int?}"
+
+<form method="POST" asp-page="/TagHelper/SelfPost" asp-route-id="10">
+<input type="submit" value="Submit" />
+</form>

test/WebSites/RazorPagesWebSite/Pages/TagHelper/FormAction.cshtml

@@ -0,0 +1,4 @@
+@page
+<button asp-page="/TagHelper/CrossPost" asp-route-id="10" />
+<input type="submit" asp-page="/TagHelper/CrossPost" asp-route-id="10" />
+<input type="image" asp-page="/TagHelper/CrossPost" asp-route-id="10" />

test/WebSites/RazorPagesWebSite/Pages/TagHelper/PathTraversalLinks.cshtml

@@ -0,0 +1,5 @@
+@page
+
+<form method="post" asp-page="../../HelloWorld" asp-antiforgery="false"></form>
+<a asp-page="../Redirects/Index" asp-route-formaction="RedirectToIndex" />
+<input type="image" asp-page="../Admin/Index" asp-fragment="my-fragment" />

test/WebSites/RazorPagesWebSite/Pages/TagHelper/SelfPost.cshtml

@@ -0,0 +1,5 @@
+@page "{id:int?}"
+
+<form method="POST" asp-page="" asp-route-id="10">
+<input type="submit" value="Submit" />
+</form>

test/WebSites/RazorPagesWebSite/Pages/TagHelper/SiblingLinks.cshtml

@@ -0,0 +1,5 @@
+@page
+
+<form method="post" asp-page="CrossPost" asp-antiforgery="false"></form>
+<a asp-page="SelfPost" asp-route-id="12" />
+<input type="image" asp-page="CrossPost" asp-fragment="my-fragment" />

test/WebSites/RazorPagesWebSite/Pages/TagHelper/SubDir/SubDirPage.cshtml

@@ -0,0 +1,2 @@
+@page "{id?}"
+ 

test/WebSites/RazorPagesWebSite/Pages/TagHelper/SubDirectoryLinks.cshtml

@@ -0,0 +1,5 @@
+@page
+
+<form method="post" asp-page="SubDir/SubDirPage" asp-antiforgery="false"></form>
+<a asp-page="SubDir/SubDirPage" asp-route-id="12" />
+<input type="image" asp-page="SubDir/SubDirPage" asp-fragment="my-fragment" />

test/WebSites/RazorPagesWebSite/Pages/TagHelper/_ViewImports.cshtml

@@ -0,0 +1 @@
+@addTagHelper "*, Microsoft.AspNetCore.Mvc.TagHelpers"