Why is the masterPath parameter in CreateView empty? - asp.net-mvc-3

Writing a small proof of concept application and wondering why the masterPath parameter is empty:
in application_start:
ViewEngines.Engines.Add(new AlternateLocationViewEngine(
new string[] {
"~/Views/Shared/_Layout.cshtml", //Is this correct? Can/should i do that
"~/Views/Shared/{0}.cshtml",
"~/Plugins/Views/Shared/{0}.cshtml",
},
new string[] {
"~/Plugins/Views/{1}/{0}.cshtml",
"~/Plugins/{1}/{0}.chstml",
"~/Plugins/Views/Shared/{0}.cshtml"
}
));
public class AlternateLocationViewEngine : RazorViewEngine
{
public AlternateLocationViewEngine(string[] masterLocations, string[] viewLocations)
: base()
{
MasterLocationFormats = masterLocations;
ViewLocationFormats = viewLocations;
PartialViewLocationFormats = ViewLocationFormats;
}
protected override IView CreateView(ControllerContext controllerContext, string viewPath, string masterPath)
{
if (string.IsNullOrEmpty(masterPath))
{
masterPath = MasterLocationFormats.ElementAt(0);
}
var nameSpace = controllerContext.Controller.GetType().Namespace;
return base.CreateView(controllerContext, viewPath.Replace("%1", nameSpace), masterPath.Replace("%1", nameSpace));
}
}
As you see i 'm forced to check if masterPath is empty in method CreateView(). Why is this? Am i missing something fundamental?
My dev environment: ASP.NET MVC3, Razor, .NET4

The masterPath will only have a value when creating a ViewResult with a masterName.
protected internal ViewResult View(string viewName, string masterName);
Internally, the RazorView handles null masterPaths in it's constructor.
// where layoutPath is the masterPath arg from the RazorViewEngine's CreateView
LayoutPath = layoutPath ?? String.Empty;
When rendering the view, the RazorView will set the OverridenLayoutPath to the masterPath (if supplied).
// An overriden master layout might have been specified when the ViewActionResult got returned.
// We need to hold on to it so that we can set it on the inner page once it has executed.
webViewPage.OverridenLayoutPath = LayoutPath;
You do not need to specify the _Layout as one of the MasterLocationFormats. Below is the default behavior for the RazorViewEngine.
MasterLocationFormats = new[] {
"~/Views/{1}/{0}.cshtml",
"~/Views/{1}/{0}.vbhtml",
"~/Views/Shared/{0}.cshtml",
"~/Views/Shared/{0}.vbhtml"
};
You can checkout the source code for more inspiration.

Related

How to generate a link to an HTTP POST action with Hyprlinkr?

I'm trying to use Hyprlinkr to generate URL to the HTTP Post action. My controller looks like this:
public class MyController : ApiController {
[HttpPost]
public void DoSomething([FromBody]SomeDto someDto) {
...
}
}
with this route:
routes.MapHttpRoute(
name: "MyRoute",
routeTemplate: "dosomething",
defaults: new { controller = "My", action = "DoSomething" });
I expect to get a simple URL: http://example.com/dosomething, but it does not work. I tried two methods:
1) routeLinker.GetUri(c => c.DoSomething(null)) - throws NullReferenceException
2) routeLinker.GetUri(c => c.DoSomething(new SomeDto())) - generates invalid URL:
http://example.com/dosomething?someDto=Namespace.SomeDto
Update:
Issue opened at github:
https://github.com/ploeh/Hyprlinkr/issues/17
I found a workaround, loosely based on Mark's answer. The idea is to go over every route parameter and remove those that have [FromBody] attribute applied to them. This way dispatcher does not need to be modified for every new controller or action.
public class BodyParametersRemover : IRouteDispatcher {
private readonly IRouteDispatcher _defaultDispatcher;
public BodyParametersRemover(String routeName) {
if (routeName == null) {
throw new ArgumentNullException("routeName");
}
_defaultDispatcher = new DefaultRouteDispatcher(routeName);
}
public Rouple Dispatch(
MethodCallExpression method,
IDictionary<string, object> routeValues) {
var routeKeysToRemove = new HashSet<string>();
foreach (var paramName in routeValues.Keys) {
var parameter = method
.Method
.GetParameters()
.FirstOrDefault(p => p.Name == paramName);
if (parameter != null) {
if (IsFromBodyParameter(parameter)) {
routeKeysToRemove.Add(paramName);
}
}
}
foreach (var routeKeyToRemove in routeKeysToRemove) {
routeValues.Remove(routeKeyToRemove);
}
return _defaultDispatcher.Dispatch(method, routeValues);
}
private Boolean IsFromBodyParameter(ParameterInfo parameter) {
var attributes = parameter.CustomAttributes;
return attributes.Any(
ct => ct.AttributeType == typeof (FromBodyAttribute));
}
}
The second option is the way to go:
routeLinker.GetUri(c => c.DoSomething(new SomeDto()))
However, when using a POST method, you'll need to remove the model part of the generated URL. You can do that with a custom route dispatcher:
public ModelFilterRouteDispatcher : IRouteDispatcher
{
private readonly IRouteDispatcher defaultDispatcher;
public ModelFilterRouteDispatcher()
{
this.defaultDispatcher = new DefaultRouteDispatcher("DefaultApi");
}
public Rouple Dispatch(
MethodCallExpression method,
IDictionary<string, object> routeValues)
{
if (method.Method.ReflectedType == typeof(MyController))
{
var rv = new Dictionary<string, object>(routeValues);
rv.Remove("someDto");
return new Rouple("MyRoute", rv);
}
return this.defaultDispatcher.Dispatch(method, routeValues);
}
}
Now pass that custom dispatcher into your RouteLinker instance.
Caveat: it's very late as I'm writing this and I haven't attempted to compile the above code, but I thought I'd rather throw an attempted answer here than have you wait several more days.
Dimitry's solution got me most of the way to where I wanted, however the routeName ctor param was a problem because StructureMap doesn't know what to put in there. Internally hyprlink is using UrlHelper to generate the URI, and that wants to know the route name to use
At that point, I see why URI generation is so tricky, because it is tied to the route names in the routing config and in order to support POST, we need to associate the method, with the correct routename and that is not known at dispatcher ctor time. Default hyprlinkr assumes there is only one route config named "DefaultRoute"
I changed Dimitry's code as follows, and adopted a convention based approach, where controller methods that start with "Get" are mapped to the route named "Get" and controller methods starting with "Add" are mapped to the route named "Add".
I wonder if there are better ways of associating a method with the proper named routeConfig?
public class RemoveFromBodyParamsRouteDispatcher : IRouteDispatcher
{
private static readonly ILog _log = LogManager.GetLogger(typeof (RemoveFromBodyParamsRouteDispatcher));
public Rouple Dispatch(MethodCallExpression method,
IDictionary<string, object> routeValues)
{
var methodName = method.Method.Name;
DefaultRouteDispatcher defaultDispatcher;
if (methodName.StartsWith("Get"))
defaultDispatcher = new DefaultRouteDispatcher("Get");
else if (methodName.StartsWith("Add"))
defaultDispatcher = new DefaultRouteDispatcher("Add");
else
throw new Exception("Unable to determine correct route name for method with name " + methodName);
_log.Debug("Dispatch methodName=" + methodName);
//make a copy of routeValues as contract says we should not modify
var routeValuesWithoutFromBody = new Dictionary<string, object>(routeValues);
var routeKeysToRemove = new HashSet<string>();
foreach (var paramName in routeValuesWithoutFromBody.Keys)
{
var parameter = method.Method
.GetParameters()
.FirstOrDefault(p => p.Name == paramName);
if (parameter != null)
if (IsFromBodyParameter(parameter))
{
_log.Debug("Dispatch: Removing paramName=" + paramName);
routeKeysToRemove.Add(paramName);
}
}
foreach (var routeKeyToRemove in routeKeysToRemove)
routeValuesWithoutFromBody.Remove(routeKeyToRemove);
return defaultDispatcher.Dispatch(method, routeValuesWithoutFromBody);
}
private static bool IsFromBodyParameter(ParameterInfo parameter)
{
//Apparently the "inherit" argument is ignored: http://msdn.microsoft.com/en-us/library/cwtf69s6(v=vs.100).aspx
const bool msdnSaysThisArgumentIsIgnored = true;
var attributes = parameter.GetCustomAttributes(msdnSaysThisArgumentIsIgnored);
return attributes.Any(ct => ct is FromBodyAttribute);
}
}

Possible to modify the Layout View value on the fly in a custom View Engine?

Currently I have a custom view engine that will detect a setting in the application configuration file and append a string to the end of view files accordingly. To use states as an example, if it detected Vermont it would append "_VT" to the end of View file names. It works fine, and if there is no "_VT" found it defaults to the file without any special ending.
Inside of my Razor Views I can use the Layout = "" option to specify a Layout for the View. My question is, is there a way I can do a similar thing to the Layout as I have done in the View Engine? Basically, if Vermont is detected in config, add "_VT" to the Layout View file name.
Current View Engine:
public class PlanSpecificRazorViewEngine : RazorViewEngine
{
public PlanSpecificRazorViewEngine()
{
ViewLocationFormats = new[] { "~/Views/{1}/{0}.cshtml", "~/Views/Shared/{0}.cshtml" };
PartialViewLocationFormats = new[] { "~/Views/{1}/{0}.cshtml", "~/Views/Shared/{0}.cshtml" };
AreaViewLocationFormats = new[] { "~/Areas/{2}/Views/{1}/{0}.cshtml", "~/Areas/{1}/Views/Shared/{0}.cshtml" };
AreaPartialViewLocationFormats = new [] {"~/Areas/{2}/Views/{1}/{0}.cshtml", "~/Areas/{2}/Views/Shared/{0}.cshtml" };
}
public override ViewEngineResult FindView(ControllerContext controllerContext, string viewName, string masterName, bool useCache)
{
string Plan = System.Configuration.ConfigurationManager.AppSettings["Plan"];
return base.FindView(controllerContext, viewName + "_" + Plan, masterName, useCache);
}
public override ViewEngineResult FindPartialView(ControllerContext controllerContext, string partialViewName, bool useCache)
{
string Plan = System.Configuration.ConfigurationManager.AppSettings["Plan"];
return base.FindPartialView(controllerContext, partialViewName + "_" + Plan, useCache);
}
}
You could set the default MasterLocationFormats in the constructor:
public PlanSpecificRazorViewEngine()
{
...
string Plan = System.Configuration.ConfigurationManager.AppSettings["Plan"];
MasterLocationFormats = new string[]
{
"~/Views/Shared/{0}_" + Plan + ".cshtml",
"~/Views/Shared/{0}_" + Plan + ".vbhtml"
};
}

ASP.NET MVC3 Physical Location of View from controller

What is the proper way to get the physical location of the View that will be served by a MVC action from inside the action?
I need the last modified time of the file for sending response headers.
The proper way to the get physical location of a view is to map its virtual path. The virtual path can be retrieved from the ViewPath property of BuildManagerCompiledView (RazorView derive from that class, and your IView instances will therefore typically have that property).
Here is an extension method that you can use:
public static class PhysicalViewPathExtension
{
public static string GetPhysicalViewPath(this ControllerBase controller, string viewName = null)
{
if (controller == null)
{
throw new ArgumentNullException("controller");
}
ControllerContext context = controller.ControllerContext;
if (string.IsNullOrEmpty(viewName))
{
viewName = context.RouteData.GetRequiredString("action");
}
var result = ViewEngines.Engines.FindView(context, viewName, null);
BuildManagerCompiledView compiledView = result.View as BuildManagerCompiledView;
if (compiledView != null)
{
string virtualPath = compiledView.ViewPath;
return context.HttpContext.Server.MapPath(virtualPath);
}
else
{
return null;
}
}
}
Use it something like this:
public ActionResult Index()
{
string physicalPath = this.GetPhysicalViewPath();
ViewData["PhysicalPath"] = physicalPath;
return View();
}
or:
public ActionResult MyAction()
{
string physicalPath = this.GetPhysicalViewPath("MyView");
ViewData["PhysicalPath"] = physicalPath;
return View("MyView");
}
That could work:
private DateTime? GetDate(string controller, string viewName)
{
var context = new ControllerContext(Request.RequestContext, this);
context.RouteData.Values["controller"] = controller;
var view = ViewEngines.Engines.FindView(context, viewName, null).View as BuildManagerCompiledView;
var path = view == null ? null : view.ViewPath;
return path == null ? (DateTime?) null : System.IO.File.GetLastWriteTime(path);
}

Routeconstraint with Ninject and dbcontext

I'm trying to build a constraint that checks against database. And I'm using Ninject, but for some reason it doesnt create a new instance of my repository when it fires.
global.asax.cs
// Content
routes.MapRoute(
"Content Language Route",
"{languageID}/List",
new { controller = "Content", action = "Index",
new { languageID = new LanguageRouteConstraint() },
new string[] { "MyProj.MVC.Controllers" }
);
.....
kernel.Bind<IContentRepository>().To<ContentRepository>();
Constraint
public class LanguageRouteConstraint : IRouteConstraint
{
#region IRouteConstraint Members
private readonly IContentRepository _contentRepository;
public LanguageRouteConstraint(IContentRepository contentRepository)
{
this._contentRepository = contentRepository;
}
public bool Match(HttpContextBase httpContext, Route route, string parameterName, RouteValueDictionary values, RouteDirection routeDirection)
{
if (routeDirection == RouteDirection.IncomingRequest)
{
string languageID = values["languageID"].ToString();
if (String.IsNullOrEmpty(languageID))
return false;
MyProj.MVC.Models.Language language = _contentRepository.GetLanguage(languageID);
return (language != null);
}
return false;
}
#endregion
}
Using Ninject for the repository works in the controller, but do I need to modify the route in gobal asa for it to make it work?
Solved it like this:
// Content
routes.MapRoute("Content Language Route",
"{languageID}/List",
new { controller = "Content", action = "Index",
new
{
languageID = new LanguageRouteConstraint(
DependencyResolver.Current.GetService<IContentRepository>())
},
new string[] { "MyProj.MVC.Controllers" }
);

How to use Razor Section multiple times in a View & PartialView (merge) without overriding it?

In the _Layout.cshtml file, I have a section at the bottom of the body called "ScriptsContent" declared like this:
#RenderSection("ScriptsContent", required: false)
In my view, I can then use this section to add scripts to be executed. But what if I also have a PartialView that also need to use this section to add additional scripts?
View
#section ScriptsContent
{
<script type="text/javascript">
alert(1);
</script>
}
#Html.Partial("PartialView")
PartialView
#section ScriptsContent
{
<script type="text/javascript">
alert(2);
</script>
}
Result
Only the first script is rendered. The second script doesn't exist in source code of the webpage.
Razor seems to only output the first #section ScriptsContent that it sees. What I would like to know is if there's a way to merge each call to the section.
If we cannot do this, what do you propose?
Here's a solution for that problem. It's from this blog: http://blog.logrythmik.com/post/A-Script-Block-Templated-Delegate-for-Inline-Scripts-in-Razor-Partials.aspx
public static class ViewPageExtensions
{
private const string SCRIPTBLOCK_BUILDER = "ScriptBlockBuilder";
public static MvcHtmlString ScriptBlock(this WebViewPage webPage, Func<dynamic, HelperResult> template)
{
if (!webPage.IsAjax)
{
var scriptBuilder = webPage.Context.Items[SCRIPTBLOCK_BUILDER] as StringBuilder ?? new StringBuilder();
scriptBuilder.Append(template(null).ToHtmlString());
webPage.Context.Items[SCRIPTBLOCK_BUILDER] = scriptBuilder;
return new MvcHtmlString(string.Empty);
}
return new MvcHtmlString(template(null).ToHtmlString());
}
public static MvcHtmlString WriteScriptBlocks(this WebViewPage webPage)
{
var scriptBuilder = webPage.Context.Items[SCRIPTBLOCK_BUILDER] as StringBuilder ?? new StringBuilder();
return new MvcHtmlString(scriptBuilder.ToString());
}
}
so anywwhere in your View or PartialView you can use this:
#this.ScriptBlock(
#<script type='text/javascript'>
alert(1);
</script>
)
and in your _Layout or MasterView, use this:
#this.WriteScriptBlocks()
There is no way to share sections between a view and partial views.
Absent a ScriptManager-like solution, you could have a collection of script files (initialized in your view and stored either in HttpContext.Items or in ViewData) to which the partial view would append the script file names it requires. Then towards the end of your view you would declare a section that fetches that collection and emits the right script tags.
The problem with the accepted answer is that it breaks Output Caching. The trick to solving this is to overwrite the OutputCache attribute with your own implementation. Unfortunately we can't extend the original attribute since it has lots of internal methods which we need to access.
I actually use Donut Output Caching which overwrites the OutputCache attribute itself. There are alternative libraries which also use their own OutputCache attribute so I will explain the steps I made to get it to work so that you can apply it to whichever one you're using.
First you need to copy the existing OutputCache attribute and place it within your application. You can get the existing attribute by looking at the source code.
Now add the following property to the class. This is where we store the script blocks so we can render the correct ones when retrieving from the cache.
public static ConcurrentDictionary<string, StringBuilder> ScriptBlocks = new ConcurrentDictionary<string, StringBuilder>();
Now inside the OnActionExecuting method you need to store the cache key (the unique identifier for the output cache) inside the current requests collection. For example:
filterContext.HttpContext.Items["OutputCacheKey"] = cacheKey;
Now modify the ViewPageExtensions class by adding the following (replacing CustomOutputCacheAttribute with the name of your attribute):
var outputCacheKey = webPage.Context.Items["OutputCacheKey"] as string;
if (outputCacheKey != null)
CustomOutputCacheAttribute.ScriptBlocks.AddOrUpdate(outputCacheKey, new StringBuilder(template(null).ToHtmlString()), (k, sb) => {
sb.Append(template(null).ToHtmlString());
return sb;
});
before:
return new MvcHtmlString(string.Empty);
Note: For a slight performance boost you'll also want to make sure you only call "template(null).ToHtmlString()" once.
Now return to your custom OutputCache attribute and add the following only when you are retrieving from the cache inside the OnActionExecuting method:
if (ScriptBlocks.ContainsKey(cacheKey)) {
var scriptBuilder = filterContext.HttpContext.Items["ScriptBlockBuilder"] as StringBuilder ?? new StringBuilder();
scriptBuilder.Append(ScriptBlocks[cacheKey].ToString());
filterContext.HttpContext.Items["ScriptBlockBuilder"] = scriptBuilder;
}
Here's the final code of my attribute:
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Text;
using System.Web;
using System.Web.Mvc;
using System.Web.UI;
using DevTrends.MvcDonutCaching;
public class CustomOutputCacheAttribute : ActionFilterAttribute, IExceptionFilter {
private readonly IKeyGenerator _keyGenerator;
private readonly IDonutHoleFiller _donutHoleFiller;
private readonly IExtendedOutputCacheManager _outputCacheManager;
private readonly ICacheSettingsManager _cacheSettingsManager;
private readonly ICacheHeadersHelper _cacheHeadersHelper;
private bool? _noStore;
private CacheSettings _cacheSettings;
public int Duration { get; set; }
public string VaryByParam { get; set; }
public string VaryByCustom { get; set; }
public string CacheProfile { get; set; }
public OutputCacheLocation Location { get; set; }
public bool NoStore {
get { return _noStore ?? false; }
set { _noStore = value; }
}
public static ConcurrentDictionary<string, StringBuilder> ScriptBlocks = new ConcurrentDictionary<string, StringBuilder>();
public DonutOutputCacheAttribute() {
var keyBuilder = new KeyBuilder();
_keyGenerator = new KeyGenerator(keyBuilder);
_donutHoleFiller = new DonutHoleFiller(new EncryptingActionSettingsSerialiser(new ActionSettingsSerialiser(), new Encryptor()));
_outputCacheManager = new OutputCacheManager(OutputCache.Instance, keyBuilder);
_cacheSettingsManager = new CacheSettingsManager();
_cacheHeadersHelper = new CacheHeadersHelper();
Duration = -1;
Location = (OutputCacheLocation)(-1);
}
public override void OnActionExecuting(ActionExecutingContext filterContext) {
_cacheSettings = BuildCacheSettings();
var cacheKey = _keyGenerator.GenerateKey(filterContext, _cacheSettings);
if (_cacheSettings.IsServerCachingEnabled) {
var cachedItem = _outputCacheManager.GetItem(cacheKey);
if (cachedItem != null) {
filterContext.Result = new ContentResult {
Content = _donutHoleFiller.ReplaceDonutHoleContent(cachedItem.Content, filterContext),
ContentType = cachedItem.ContentType
};
if (ScriptBlocks.ContainsKey(cacheKey)) {
var scriptBuilder = filterContext.HttpContext.Items["ScriptBlockBuilder"] as StringBuilder ?? new StringBuilder();
scriptBuilder.Append(ScriptBlocks[cacheKey].ToString());
filterContext.HttpContext.Items["ScriptBlockBuilder"] = scriptBuilder;
}
}
}
if (filterContext.Result == null) {
filterContext.HttpContext.Items["OutputCacheKey"] = cacheKey;
var cachingWriter = new StringWriter(CultureInfo.InvariantCulture);
var originalWriter = filterContext.HttpContext.Response.Output;
filterContext.HttpContext.Response.Output = cachingWriter;
filterContext.HttpContext.Items[cacheKey] = new Action<bool>(hasErrors => {
filterContext.HttpContext.Items.Remove(cacheKey);
filterContext.HttpContext.Response.Output = originalWriter;
if (!hasErrors) {
var cacheItem = new CacheItem {
Content = cachingWriter.ToString(),
ContentType = filterContext.HttpContext.Response.ContentType
};
filterContext.HttpContext.Response.Write(_donutHoleFiller.RemoveDonutHoleWrappers(cacheItem.Content, filterContext));
if (_cacheSettings.IsServerCachingEnabled && filterContext.HttpContext.Response.StatusCode == 200)
_outputCacheManager.AddItem(cacheKey, cacheItem, DateTime.UtcNow.AddSeconds(_cacheSettings.Duration));
}
});
}
}
public override void OnResultExecuted(ResultExecutedContext filterContext) {
ExecuteCallback(filterContext, false);
if (!filterContext.IsChildAction)
_cacheHeadersHelper.SetCacheHeaders(filterContext.HttpContext.Response, _cacheSettings);
}
public void OnException(ExceptionContext filterContext) {
if (_cacheSettings != null)
ExecuteCallback(filterContext, true);
}
private void ExecuteCallback(ControllerContext context, bool hasErrors) {
var cacheKey = _keyGenerator.GenerateKey(context, _cacheSettings);
var callback = context.HttpContext.Items[cacheKey] as Action<bool>;
if (callback != null)
callback.Invoke(hasErrors);
}
private CacheSettings BuildCacheSettings() {
CacheSettings cacheSettings;
if (string.IsNullOrEmpty(CacheProfile)) {
cacheSettings = new CacheSettings {
IsCachingEnabled = _cacheSettingsManager.IsCachingEnabledGlobally,
Duration = Duration,
VaryByCustom = VaryByCustom,
VaryByParam = VaryByParam,
Location = (int)Location == -1 ? OutputCacheLocation.Server : Location,
NoStore = NoStore
};
} else {
var cacheProfile = _cacheSettingsManager.RetrieveOutputCacheProfile(CacheProfile);
cacheSettings = new CacheSettings {
IsCachingEnabled = _cacheSettingsManager.IsCachingEnabledGlobally && cacheProfile.Enabled,
Duration = Duration == -1 ? cacheProfile.Duration : Duration,
VaryByCustom = VaryByCustom ?? cacheProfile.VaryByCustom,
VaryByParam = VaryByParam ?? cacheProfile.VaryByParam,
Location = (int)Location == -1 ? ((int)cacheProfile.Location == -1 ? OutputCacheLocation.Server : cacheProfile.Location) : Location,
NoStore = _noStore.HasValue ? _noStore.Value : cacheProfile.NoStore
};
}
if (cacheSettings.Duration == -1)
throw new HttpException("The directive or the configuration settings profile must specify the 'duration' attribute.");
if (cacheSettings.Duration < 0)
throw new HttpException("The 'duration' attribute must have a value that is greater than or equal to zero.");
return cacheSettings;
}
}
I also had to modify the Donut Output Cache library to make IExtendedOutputCacheManager and the OutputCacheManager constructor public.
Please note this has been extracted from my application and may require some minor tweaks. You should also place WriteScriptBlocks at the bottom of the page so it is not called until after all child actions are triggered.
Hope this helps.

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