Generating urls from MVC Routes in a Management layer... - model-view-controller

So... I have a business object/manager which is going to generate emails.
These emails will contain links to various content on the website... and therefore needs to understand about MVC routing.. or at least how to generate URLs for the website...
However my business object will not have access to a RequestContext etc and the email generation is not necessarily the result of a web request to a website (I have a dispatcher which runs on a background thread which will be generating the emails)
Any ideas how I can generate my urls without having access to a request - and therefore being unable to use URLHelper...
Thoughts?

In order to get at the UrlHelper outside of the controller, you need to feed it and the routing data the HttpContext. Here's an example:
using System.Web;
using System.Web.Mvc;
using System.Web.Routing;
HttpContextBase context = new HttpContextWrapper(HttpContext.Current);
UrlHelper helper = = new UrlHelper(new RequestContext(context, RouteTable.Routes.GetRouteData(context)));

I prefer to define schema and make both routing and business logic aware of it. Means different implementations of the same URL schema.
Some reasons why:
Your routing mechanism could change. For example in feature you can switch to url_rewrite module.
Possible issues with load-balanced installation.
You do not need even to try to use URLHelper in undocumented way.
BTW, you can replace HttpRequest from URLHelper easily. We used to use this for unit-testing. For more information just search for unit testing of the HttpContextBase or look at examples in source code of the MvcContrib. This can help to instantiate URL helper and all related stuff in non hosted environment. But I still do not think that this is a good idea.

In ASP.NET MVC5 (and possibly MVC4 - I'm not sure when it was introduced), you can do this more directly using HttpRequest.RequestContext. Eg:
var urlHelper = new UrlHelper(HttpContext.Current.Request.RequestContext);

Related

Session object not available in WebAPI

I've got a webAPI that uses Entity Framework. I'm trying to cache some data in the session variable following along in this article:
https://msdn.microsoft.com/en-us/library/system.web.httpcontext.session(v=vs.110).aspx
I can't seem to do it though. The Session object isn't available.
In my controller, I try this:
Session["mappings"] = mappings;
...but it doesn't recognize what Session is.
I also try this:
HttpContext.Current.Session["mappings"] = mappings;
...and this:
Page.Session["mappings"] = mappings;
...but it doesn't know what HttpContext or Page are.
I'm including System.Web in my project references. I'm also including this in my web.config:
...just like this article says:
https://msdn.microsoft.com/en-us/library/ms178581(v=vs.110).aspx
...but to no avail.
My work colleague suggests it's because our webAPI is RESTful which means it's stateless, so no session object. However, we know there are ways around this. What I need is simply some way of persisting data in some kind of cache that will survive across several requests.
I also need something that will be available inside EF entities (not just the webAPI controller) is that's possible.
Does anyone know how to solve this problem? Thanks.
As your colleagues correctly suggested, an API is stateless, each request is separate and needs to have all the data required to complete the request.
You can add a caching layer however, but that is not going to be done via the Session object. Session makes no sense in an API.
Have a look here for some ideas: Caching Data in Web API

"Default principal object cannot be set twice" error implementing WEB API with CSLA backend

Can anyone save some of my hair? :)
I'm trying to create an asp.net WEB API interface for an older CSLA (1.x/2.x era) project. I am testing by hard coding the login on every request in various ways (once in the startup code, as an authorization request filter, inside the individual route request etc etc). All the ways I tried work exactly once perfectly and then I get the infamous:
'Default principal object cannot be set twice.'
exception in BusinessPrincipal.vb (yeah I know it's very old, but it's released software, I can't upgrade CSLA)
I know that there is an issue where you need to set HttpContext.Current.User = Thread.CurrentPrincipal; due to some internal workings of the web API and I do that already, that has not resolved the issue.
I'd like to know if anyone has implemented a web api front end and how they handled this issue or any pointers as to what could be the solution.
Worst case scenario if I could at least just login once and keep that same principal without losing it I could implement a second layer of security, that woudld be acceptable, barring anything else is there some way to just login once and not lose that principal?
That BusinessPrincipal class would be in your code base, not in CSLA itself. The Csla.Security namespace does include a BusinessPrincipalBase that is probably the base class for your BusinessPrincipal.
Classes in that namespace are here in GitHub
It is true that you can only call AppDomain.SetPrincipalPolicy one time, but you should be able to set the Thread.CurrentPrincipal and HttpContext.Current.User multiple times.

Can you use WcfTestClient against WebApi?

This article suggests it was possible, or in the works, with some code that suggests it can be done, but I can't figure out what code needs to happen or the WcfTestClient's uri needs to be.
Here's the code from the article that makes me think I can do it:
// Metadata routes to support $metadata and code generation in the WCF Data Service client.
configuration.Routes.MapHttpRoute(
ODataRouteNames.Metadata,
"$metadata",
new { Controller = "ODataMetadata", Action = "GetMetadata" }
);
Is this feature implemented?
No, it does not work as you intend. WCF Test Client supports talking to SOAP-based services. OData is not supported in the current version.
Granted, as #Snixtor mentioned, you could create a SOAP service using ASP.NET Web API, including support for metadata (WSDL). But I really don't know of any good reason why anyone would want to do that.

MVC3 is valid email

Is there a built in function which will test if an email address is valid?
I want to test the email address structure is valid before sending a confirmation email to the end user.
I understand i could create my own function easy enough with the use of a regular expression but if there is a built in function i would much rather use this.
You can do this with Data Annotations extensions I believe. Check out Scott Guthrie's blog post on it here: http://weblogs.asp.net/srkirkland/archive/2011/02/23/introducing-data-annotations-extensions.aspx.
There is a good point in Scott's post as to why you would use this rather than the MVC 3 Futures validators which might be relevant to your choice:
ASP.NET MVC 3 futures defines four new data annotations attributes which this project has as well: CreditCard, Email, Url and EqualTo. Unfortunately referencing MVC 3 futures necessitates taking an dependency on MVC 3 in your model layer, which may be unadvisable in a multi-tiered project. Data Annotations Extensions keeps the server and client side libraries separate so using the project’s validation attributes don’t require you to take any additional dependencies in your model layer which still allowing for the rich client validation experience if you are using MVC 3.
Yes, you can use
public class CustomerMetaData
{
// Add type information.
[DataType(DataType.EmailAddress)]
public object EmailAddress;
}
on your model. See more about it here.
however, last time I checked it does not work client sided.
I googled it, and from imran baloch's blog post it seems it does work now.

Cannot access text file in ASP.Net MVC 3 test project

I am trying to access a text file in asp.net mvc3 test project, the common way I know to access it is through HttpContext class like this
HttpContext.Current.Server.MapPath("Temp.txt");
But it returns "Current" as null!
After a little search I found few reasons of Current being null, in my case it is I guess using a router handler to route requests.
But not getting the way to do it for my case.
Can anyone help me on that?
HttpContext is not available on test context, only on web enviroment. You need an HttpContext stub. Avoid this direct dependence.
http://vkreynin.wordpress.com/2009/03/23/stub-htttpcontext/

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