Account management in application based on HotTowel - breeze

I have built an application based on HotTowel template and so far it looks great. With a minor problem... It has no account management. SimpleMembership and SimpleRole have been implemented and so far everything works as intended. Accounts are based on ASP.NET MVC SPA template. What I can do is - add new Users only in Seed method (there should be no register, only administrator can add people) and once they are set, they can't be changed. It is not a problem to include views from SPA template and use those for management, but that doesn't fit into HotTowel very well. Only login fits into this, and logout is being handled in a weird way - hidden written in index.cshtml and then being called with:
$.("#hiddenLogoutForm").submit()
The question is - how should I handle account management with currently built application? Would this be the time to introduce 2nd breeze manager to handle UserContext or is there any better way? Considering I already use AccountController for login and logout, would it be good to make BreezeAccountController (or similar name) just for breeze read/writes? Would login/logout still work as intended if I just added [BreezeController] decorator to AccountController? How to best connect Roles and User info? Password changes? Only UserProfile is visible in the context by default so any other change will have to be saved through some other Action method. Is it worth trying with breeze or just simply write ajax calls?
Any suggestions are welcome.
Thanks in advance!

So, here is how I handled it:
I made a copy of AccountController and called it BreezeAccountController and gave it [BreezeController] attribute. After that I did a bit of a clean-up and left only methods I wanted and added a couple more. Also, changed it to use UsersContext.
All data that is allowed to be [HTTPGet] works perfectly with Breeze. For everything else except SaveChanges, I had to write my own ajax calls. Fortunately, it is as simple as this:
return $.ajax({
type: "POST",
url: "./breeze/breezeAccount/ActionMethod",
data: JSON.stringify(data),
success: querySucceeded,
dataType: 'json',
contentType: 'application/json; charset=utf-8'
});
What might be hard is how to read data, but that is pretty simple as well. Variable data on client is a simple object with some properties. On server, I added a new class with exactly the same properties as JSON-ed data on client and then my action method looks like this:
[HttpPost]
[Authorize(Roles = "Admin")]
[System.Web.Mvc.ValidateAntiForgeryToken]
public object ActionMethod(PostedData data)
{
// usage: data.property1
// and do whatever you want, register, validate, change etc..
}
Making some methods POST and not being able to use breeze for them might seem a bit clumsy, but for account management, I think it's worth the trouble.

Related

ASP.NET WEB API Multiple Interfaces

I am designing ASP.NET WEB API service with two interfaces. First interface is read-only and second one is admin interface (to be used with MVC app) with full CRUD support. Does anyone know where I can get more information on such setup, any tutorials, walk thought, sample design document?
Also does it worth splitting these into two interfaces or keep them in same? But problem is that in read-only I expose 2-3 properties for every object while for admin there are 10-15?
Similar setup for WCF or design spec will do.
If I understand what your wanting to do, may I suggest rather than having one URL, i.e. \dataStuff\dataView split off into another view, maybe \dataStuff\edit\ which only admin's have access to, can be done like so:
[Authorize(Roles = "Administrators")]
public ActionResult edit()
{
return View();
}
then next to each data element that your viewing add the following to ONLY admin's through use of User.IsInRole
#foreach (var item in Model.dataTable)
{
#*
write a value from the data table here
*#
#Html.ActionLink("edit", "edit").If(User.IsInRole("Administrators"))
<br/>
}
obviously you don't have to display your data like this, I'm just showing that you add to the end of each element of the database an edit ActionLink IF the user is admin.
This allows your admin to view data like a user and also have the added functionality they need. Code re-use is better than a single view which has two states, Admin and non Admin.
Sorry if this isn't the best explanation, fairly new to MVC
Seems like this concept is sometimes called CQRS.
Sample: http://martinfowler.com/bliki/CQRS.html

How to track "Last Activity" with ASP.NET MVC4 Action Filters

I'm trying to maintain a "Last Active" DateTime field on every User's Profile - Originally I was going to tie this check to some Index() controller but the user might not always call that controller, so I need something global.
Action Filters seem to apply on the Controller level at the highest, so now I'm wondering if some magic in Global.asax might do the trick. This seems like a common enough problem but I wasn't able to pull anything up in the Google or on SO - apologies if it's a dup.
What do you mean by "the user might not always call the controller"? If you have an mvc web application, then user interaction will always be with an action on a controller.
However, I would suggest using an HTTP module. An HTTP module class will always run for each call, and I think it will be a better choice for your issue. http://support.microsoft.com/kb/307996 might be a good reference for that, or just google it and you will find many results that help you with implementing it.
Edit:
If you have already implemented a filter, you can apply it to all actions simply by adding code simlar to below to your global.asax (applicaton_start() method)
var myfilter = new MyFilter();
GlobalConfiguration.Configuration.Filters.Add(myfilter);

How can I write an MVC3/4 application that can both function as a web API and a UI onto that API?

My title sums this up pretty well. My first though it to provide a few data formats, one being HTML, which I can provide and consume using the Razor view engine and MVC3 controller actions respectively. Then, maybe provide other data formats through custom view engines. I have never really worked in this area before except for very basic web services, very long ago. What are my options here? What is this Web API I see linked to MVC4?
NOTE: My main HTML app need not operate directly off the API. I would like to write the API first, driven by the requirements of a skeleton HTML client, with a very rudimentary UI, and once the API is bedded down, then write a fully featured UI client using the same services as the API but bypassing the actual data parsing and presentation API components.
I had this very same thought as soon as the first talk of the Web API was around. In short, the Web API is a new product from the MS .NET Web Stack that builds on top of WCF, OData and MVC to provide a uniform means of creating a RESTful Web API. Plenty of resources on that, so go have a Google.
Now onto the question..
The problem is that you can of course make the Web API return HTML, JSON, XML, etc - but the missing piece here is the Views/templating provided by the Razor/ASPX/insertviewenginehere. That's not really the job of an "API".
You could of course write client-side code to call into your Web API and perform the templating/UI client-side with the mass amount of plugins available.
I'm pretty sure the Web API isn't capable of returning templated HTML in the same way an ASP.NET MVC web application can.
So if you want to "re-use" certain portions of your application (repository, domain, etc), it would probably be best to wrap the calls in a facade/service layer of sorts and make both your Web API and seperate ASP.NET MVC web application call into that to reduce code.
All you should end up with is an ASP.NET MVC web application which calls into your domain and builds templated HTML, and an ASP.NET Web API application which calls into your domain and returns various resources (JSON, XML, etc).
If you have a well structured application then this form of abstraction shouldn't be a problem.
I'd suggest developing your application in such a way that you use a single controller to return the initial application assets (html, javascript, etc) to the browser. Create your API / logic in WebAPI endpoint services and access those services via JavaScript. Essentially creating a single page application. Using MVC 4 our controller can return different Views depending on the device (phone, desktop, tablet), but using the same JavaScript all of your clients will be able to access the service.
Good libraries to look into include KnockoutJS, SammyJS , or BackBoneJS
If you do have a requirement to return HTML using the WebAPI e.g. to allow users to
click around and explore your API using the same URL then you can use routing\an html message handler.
public class HtmlMessageHandler : DelegatingHandler
{
private List<string> contentTypes = new List<string> { "text/html", "application/html", "application/xhtml+xml" };
protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
{
if (request.Method == HttpMethod.Get && request.Headers.Accept.Any(h => contentTypes.Contains(h.ToString())))
{
var response = new HttpResponseMessage(HttpStatusCode.Redirect);
var htmlUri = new Uri(String.Format("{0}/html", request.RequestUri.AbsoluteUri));
response.Headers.Location = htmlUri;
return Task.Factory.StartNew<HttpResponseMessage>(() => response);
}
else
{
return base.SendAsync(request, cancellationToken);
}
}
}
For a full example check out:-
https://github.com/arble/WebApiContrib.MessageHandlers.Html
I've played with this idea before. I exposed an API through MVC3 as JSONResult methods on different controllers. I implemented custom security for the API using controller action filters. Then built a very AJAX heavy HTML front-end which consumed the JSON services. It worked quite well and had great performance, as all data transferred for the web app was through AJAX.
Frederik Normen has a good post on Using Razor together with ASP.NET Web API:
http://weblogs.asp.net/fredriknormen/archive/2012/06/28/using-razor-together-with-asp-net-web-api.aspx
One important constraint of a well designed REST service is utilizing "hypermedia as the engine of application state" (HATEOAS - http://en.wikipedia.org/wiki/HATEOAS).
It seems to me that HTML is an excellent choice to support as one of the media formats. This would allow developers and other users to browse and interact with your service without a specially built client. Which in turn would probably result in the faster development of a client to your service. (When it comes to developing actual HTML clients it would make more sense to use a json or xml.) It would also force a development team into a better designed rest service as you will be forced to structure your representations in such a way that facilitates an end users navigation using a browser.
I think it would be smart for any development team to consider taking a similar approach to Frederik's example and create a media type formatter that generates an HTML UI for a rest service based on reflecting on the return type and using conventions (or something similar - given the reflection I would make sure the html media format was only used for exploration by developers. Maybe you only make it accessible in certain environments.).
I'm pretty sure I'll end up doing something like this (if someone hasn't already or if there is not some other feature in the web api that does this. I'm a little new to Web API). Maybe it'll be my first NuGet package. :) If so I'll post back here when it's done.
Creating Html is a job for an Mvc Controller not for Web Api, so if you need something that is able to return both jSon and Html generated with some view engine the best option is a standard Mvc Controller Action methosd. Content Negotiation, that is the format to return, can be achieved with an Action Fiter. I have an action filter that enable the the controller to receive "hints" from the client on the format to return. The client can ask to return a view with a specific name, or jSon. The hint is sent either in the query string or in an hidden field (in case the request comes from a form submit). The code is below:
public class AcceptViewHintAttribute : ActionFilterAttribute
{
private JsonRequestBehavior jsBehavior;
public AcceptViewHintAttribute(JsonRequestBehavior jsBehavior = JsonRequestBehavior.DenyGet)
{
this.jsBehavior = jsBehavior;
}
public override void OnActionExecuted(ActionExecutedContext filterContext)
{
string hint = filterContext.RequestContext.HttpContext.Request.Params["ViewHint"];
if (hint == null) hint = filterContext.RequestContext.RouteData.Values["ViewHint"] as string;
if (!string.IsNullOrWhiteSpace(hint) && hint.Length<=100 && new Regex(#"^\w+$").IsMatch(hint) )
{
ViewResultBase res = filterContext.Result as ViewResultBase;
if (res != null)
{
if (hint == "json")
{
JsonResult jr = new JsonResult();
jr.Data = res.ViewData.Model;
jr.JsonRequestBehavior = jsBehavior;
filterContext.Result = jr;
}
else
{
res.ViewName = hint;
}
}
}
base.OnActionExecuted(filterContext);
}
}
Now that it's been a little while through the Beta, MS just released the Release Candidate version of MVC4/VS2012/etc. Speaking to the navigation/help pages (mentioned by some other posters), they've added a new IApiExplorer class. I was able to put together a self-documenting help page that picks up all of my ApiControllers automatically and uses the comments I've already put inline to document them.
My recommendation, architecture-wise, as others have said as well, would be to abstract your application into something like "MVCS" (Model, View, Controller, Services), which you may know as something else. What I did was separate my models into a separate class library, then separated my services into another library. From there, I use dependency injection with Ninject/Ninject MVC3 to hook my implementations up as needed, and simply use the interfaces to grab the data I need. Once I have my data (which is of course represented by my models), I do whatever is needed to adjust it for presentation, and send it back to the client.
Coming from MVC3, I have one project that I ported to MVC4, which uses the "traditional" Razor markup and such, and a new project that will be a single page AJAX application using Backbone + Marionette and some other things sprinkled in. So far, the experience has been really great, it's super easy to use. I found some good tutorials on Backbone + Marionette here, although they can be a bit convoluted, and require a bit of digging through documentation to put it all together, it's easy once you get the hang of it:
Basic intro to Backbone.js: http://arturadib.com/hello-backbonejs/docs/1.html
Use cases for Marionette views (I found this useful when deciding how to create views for my complex models): https://github.com/derickbailey/backbone.marionette/wiki/Use-cases-for-the-different-views

ASP.Net MVC: Check if URL is Authorized

I'd like to simply check from a Controller whether another URL is authorized.
So for example, I'd like to call into a Controller like so:
[HttpPost]
public ActionResult IsUrlAuthorized(string url)
{
bool isAuthorized = // What do I put here?
return Json(isAuthorized);
}
So I'd like to know what I could call to check on whether the current user is authorized for the passed-in URL or not. I'm guessing the answer has something to do with Routes, which sit a little bit outside MVC?
This is a somewhat similar question but not quite the same thing:
ASP.NET MVC. Check if user is authorized from JavaScript
Since the user may or may not be authorized in general, but may not have the right permissions or role assignments to see a specific URL.
Ideas?
Update: I use standard MVC authorization attributes to lock down my app, so I'll just give an example of what that looks like here. In MVC Routes map to Controllers. A single method on a Controller can be restricted to one or more Roles:
public class HomeController : Controller
{
[Authorize(Roles = "User, Moderator")]
public ActionResult ListRecentPosts()
{
. . .
}
}
Or, an entire Controller can be restricted to one or more roles:
[Authorize(Roles = "Admin")]
public class AdminController : Controller
. . .
The actual URL that any of these controller methods responds to is based on a default mapping in a standard MVC app:
routes.MapRoute("Default",
"{controller}/{action}/{id}",
new { controller = "Home", action = "Index", id = UrlParameter.Optional }
);
But, you can be nice to your users and make URLs guessable by adding a lot more Routes - as a result, a Controller method can have many names that point to it. You can't just assume and infer the controller name from the URL (even if it maps out that way for half the URLs in the site).
So presumably I either need a way to ask the Routing engine directly whether a URL is authorized for the current user, or a 2-step of asking the Routing engine for which Controller and Method, then ask if those are authorized - hopefully not by using Reflection and matching Roles directly as that again would appear to assume too much.
Update 2: The way this came up is I have an Account strip at the top of my app. Its state can change by selecting one of several accounts you're authorized as. Depending on where you are in the app, the account you chose might have authorization to view this page - and you might be in the middle of filling out a form you don't want to lose. So the naive approach - just refresh when they pick another account - is harmful, and a waste of the user's time even if there is no form and they're just reading a page that's all text.
While that convenience to the user is nice, the user is going to fairly assume that pages they can't see as a user who shouldn't have permission really are denied (and, it would be harmful to leave them on a page that's forbidden - actions taken from it will fail). So I need to know whether to redirect away based on their new permissions.
One of the things I love about .Net is the way many of its best libraries decompose so well, so you can easily recompose things that are part of its normal functionality, or a new twist. Both the Routing module and MVC appear to be very well constructed, so I have to suspect this can be done.
The cheap hack is to ensure that my authorization module returns a consistent redirect status code when a user isn't authorized, and when the user changes their account in the account strip, fire 2 AJAX calls: One to change account, and then a second to the current page over AJAX just to check the HTTP Status Code. 200 OK means leave the page as is, Redirect means follow the redirect. Obviously this is a little ugly, involves an extra HTTP call, creates a false hit in the logs, and makes an assumption about how authorization is handled across the app.
There could be a secondary concern - the page might be authorized, but just change how it works or looks. This particular app has no change in look based on account (besides the account strip itself), and I can handle functionality changes by just providing a custom event that forms listen to - they can reload any relevant data from the server in response to it.
Using UrlAuthorization.CheckUrlAccessForPrincipal only works if you're only using URL authorization. But for MVC using Routing, we highly recommend that you don't use URL authorization to secure an app.
Instead, we recommend using Authorization attributes on the controller class. The reason is there could be multiple URLs that call the same controller action. It's always better to secure the resource at the the resource and not just at the entry ways.
In this particular case, you'd have to get an instance of the controller given the URL. THat's a little tricky as you'll basically have to run the MVC pipeline from the point where you have the URL to the point where you have the controller. It's possible, but seems heavyweight.
I wonder if there isn't a better and simpler way to accomplish your goals. What is it you're really trying to do?
UPDATE: Based on your scenario, it sounds like this is an initial check just for UI purposes. Perhaps all you need to do is make an asynchronous Ajax request to the URL and check the HTTP Status code. If it's a 401 status code, you know the user is not authorized. That seems like the safest bet.
How about UrlAuthorizationModule.CheckUrlAccessForPrincipal method.
UrlAuthorizationModule.CheckUrlAccessForPrincipal Method (System.Web.Security)

Creating an API with ASP.NET MVC - All in one project, or two projects?

So I've recd. a requirement to create an API to access our application. Not all controller actions are covered by the API (maybe 50%).
I figure I can either use the same project, check the http headers for each request and respond with either xml, JSON or html as required (much like rails).
OR
Create a new ASP.NET MVC application, deploy # api.myapp.com and use it exclusively for API access.
I assume I could write a base controller for the first option to handle 99% of the work. The issue with the first option is we don't need (or want) API functionality for at least 1/2 of controller actions (and prob. never will).
In the second option I have a duplicate of some controllers, but the good news is most/all? my controller actions are only a couple lines of code. Typically:
Whatever whatever = new Whatever(....);
repository.Save(whatever);
Anyway, what do the stack overflowers think?
It seems that you want to create something like REST service. Please have a look at this post of Phil Haack.
Yes, I'm sure you can put it in the same project. But it will be better to separate them in some way (using areas from MvcContrib or move controllers of api and web application to separate assemblies like this done in SharpArchitecture. If your controllers duplicate a lot of code you may create generic controller like:
public class ControllerBase<T, Service> : Controller
where Service : IService<T>
{
public Service service { get; set; }
public ActionResult Save(int id)
{
var item = service.Get(id);
if (TryUpdateModel<T>(item))
{
service.Save(item);
return View("Success");
}
return View("Error", item);
}
}
Hope this helps.
I think I'd put in the same project, but segregate it using separate routes.
API: http://example.com/api/widget/list
App: http://example.com/widget/list
You could then reuse as much code as possible -- push the data selection and other code into your BLL, for instance. Keeping it in the same project will make it easier to use your API code via AJAX from the client.
I think putting the same code in 2 different projects is asking for trouble in the long run.
Put it all in the same project.
If you need some seperation between regular vs API requests you can use seperate routes.
You can then make a private function that does the action and just have the public facing one decide to render in html or JSON/XML

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