Imagine we were doing this StackOverflow site in ASP.NET MVC (funny that, 'cause it is...). We have to develop the views:
About this site
Faq
Privacy policy
404 page
Error page
etc...
Now, because we want to keep this RESTful because we're trying to grow our RESTafarian Geek-fro's, do we throw them into one controller .. called .. (eeks... er..) MiscellaneousController or FrameworkController or Controller .. each one with their own action methods ...
or
Do we have one controller for each, and each one of these controllers has it's own Index action.
Now, technically, I KNOW you can do it either way. So this is not a question about how to technically do it. It's more about the proper practice, if keeping to a nice and hippie RESTful way.
Thoughts?
The "REST"ness will come from your routing not your controller if I understand you correctly.
If you mean which way should you do it in terms of the MVC programming technique, I would be tempted to create a MiscController with a "generic" or "index" method that takes an id/topic parameter and then renders a page.
This is because the action of all of these pages is the same - render some generic content.
In this way they could all use the same view, and perhaps just read the display text from a database.
If you are going to have a different view for each section I would use a different action for each section.
I tend to use a new Controller for any site "segment" or grouped functionality and an action for each possible view or exeuction action.
Related
I am currently working with mvc4 and have a question around best practice.
I am passing back to my view, a number of links based on product information eg. product/1234 etc.
What is best practice, create the link using the routing engine in the controller and return the url as a property on the model object OR return the information to the view and generate the link there? I use automapper to map my DTO objects to model object, also considering creating the links during mapping.
What is the best practice with this?
You always create the link on the view.
The HTML helpers in the view can be used to ensure the link conforms to your routing rules.
You can see this in action in the many official ASP.NET MVC 4 Tutorials.
Why not in the controller or model?
The HTML helpers in the view are designed to create not just the URL, but also to wrap the URL in a fully formed anchor tag, etc. It isn't appropriate to have HTML in your model or controller as they shouldn't care how the data is displayed.
For example, the Html.ActionLink helper returns an a element.
I'm looking at developing an application that will include a CMS. I'm a seasoned web forms developer but only really just moving into MVC.
I have a couple of questions that I hope some of you guys can answer:
First, my current web forms CMS allows users to create a page, and then "drop" any number of user controls onto that page they have created. The way I do this is to create an entry in the DB together with the path and then use the LoadControl method.
I can see I can do this with partial views, but partial views have no code behind. If I've potentially got 100 controls that people can drop onto a page, does this mean that the ViewBag in the controller needs to cater for all 100 controls just in case they are used on the view? For example, a web forms user control will contain logic: rptItems.DataSource = blah; rptItems.DataBind()
With MVC, I'm assuming that logic will be in the view controller and the view would access it by the ViewBag? I'm a little confused at how to do this.
Secondly, how would you handle deep routing?
EG:
Store/Products/Category is fine, but what about Store/Products/Category/Delivery/UK ? Would I need to set up a route in global.asax for each route I need? In web forms, I just called the ReWritePath method and handled the routing myself using regular expressions.
Thanks for the time to read this, and hopefully answer some of my queries
For your second question, (ie, "deep routing"), you can handle this within your controller instead of adding real routes. Each part of the url is available via the RouteData.Values collection inside of your controller action. So, your route may look like
~/Store/Products/Category/{*params}
Assuming typical route configuration, this would call the Category(...) action method on ~/areas/store/controllers/storeController, which could then grap delivery and uk from the RouteData.Values collection.
There are a lot of other approaches to this - storing routes in a database and using associated metadata to find the correct controller and method - but I think this is the simplest. Also, it may be obvious, but if you really only need two parameters beyond 'Category' in your example, you could just use
public ActionResult Category(string category, string region)
{
...
}
and a route:
~/store/{controller}/{action}/{category}/{region}/{*params}
Delivery and UK would be mapped to the the category and region parameters, respectively. Anything beyond uk would still be available via the RouteData.Values collection. This assumes that you don't have more specific routes, like
~/store/{controller}/{action}/{category}/{region}/{foo}/{bar}/{long_url}/{etc}
that would be a better match. ({*params} might conflict with the second route; you'll have to investigate to see if it's a problem.)
For your first question:
You can dynamically generate the view source and return it as a string from the controller, eliminating the need to pass a lot of stuff via ViewBag. If a virtual page from your CMS database requires inclusion of partial views, you would add the references to those components when generating the page. (This may or may not address your problem - if not, please provide more information.)
I have looked all over for elegant solutions to this not so age-old question. How can I lock down form elements within an ASP.Net MVC View, without adding if...then logic all over the place?
Ideally the BaseController, either from OnAuthorization, or OnResultExecultion, would check the rendering form elements and hide/not render them based on role and scope.
Another approach I have considered is writing some sort of custom attributes, so as to stay consistent with how how we lock down ActionResults with [Authorize]. Is this even possible without passing a list of hidden objects to the view and putting if's all over?
Other background info: We will have a database that will tell us at execution time (based on user role/scope) what elements will be hidden. We are using MVC3 with Razor Viewengine. We're utilizing a BaseController where any of the Controller methods can be overridden.
Any help on this would be deeply appreciated!
You could use a number of different methods:
Send the user to a different view (display only view) based on the action filter, or a condition in the controller.
On a field basis, you could build the logic into the editor templates to read custom data-annotations based on role/permission.
You can build HTML helpers to handle the logic and render the appropriate partial view, css class, or text.
For more reading:
How much logic is allowed in ASP.NET
MVC views?
ASP.NET MVC 2 Templates, Part 1: Introduction (there are 5 parts, very informative and a good place to start developing your own editor templates)
Take the example of wanting to have a "Latest news items" sidebar on every page of your ASP.NET MVC web site. I have a NewsItemController which is fine for pages dedicating their attention to NewsItems. What about having a news sidebar appear on the HomeController for the home page though? Or any other controller for that matter?
My first instinct is to put the logic for selecting top 5 NewsItems in a user control which is then called in the Master Page. That way every page gets a news sidebar without having to contaminate any of the other controllers with NewsItem logic. This then means putting logic in what I understood to be the presentation layer which would normally go in a Controller.
I can think of about half a dozen different ways to approach it but none of them seem 'right' in terms of separation of concerns and other related buzz-words.
I think you should consider putting it in your master page. Your controller can gather data (asynchronously, of course), store it in a nice ViewModel property for your view (or in TempData) and then you can call RenderPartial() in your master page to render the data.
The keeps everything "separate"
http://eduncan911.com/blog/html-renderaction-for-asp-net-mvc-1-0.aspx
This seems to address the question - even using the instance of a sidebar - but using a feature not included with MVC 1 by default.
http://blogs.intesoft.net/post/2009/02/renderaction-versus-renderpartial-aspnet-mvc.aspx
This also indicates the answer lies in RenderAction.
For anyone else interested, here's how I ended up doing it. Note you'll need to the MVC Futures assembly for RenderAction.
Basically you'd have something like this in your controller:
public class PostController
{
//...
public ActionResult SidebarBox()
{
// I use a repository pattern to get records
// Just replace it with whatever you use
return View(repoArticles.GetAllArticles().Take(5).ToList());
}
//...
}
Then create a partial view for SidebarBox with the content you want displayed, and in your Master Page (or wherever you want to display it) you'd use:
<% Html.RenderAction<PostController>(c => c.SidebarBox()); %>
Not so hard after all.
You can create a user control (.ascx) and then call RenderPartial().
Design a method in your controller with JsonResult as return type. Use it along with jQuery.
Use RenderAction() as suggested by elsewhere.
News section with ASP.NET MVC
On the main page of my site, I would like to show several views which rely on their own controllers for data retrieval. I do not want to retrieve anything from the DAL in my Home controller.
For example, I want to show view listing top 5 news, a view with random quote from the database, another view with the users shopping cart contents, etc.
After Googling around, I found RenderAction method which is almost perfect, but it's not available in RC1, only in Futures, and apparently, it has some issues.
I found RenderPartial as well, but that relies on the main controller to pass data to the view.
Additional clarification:
The main reason I do not want data access logic in the Home controller is to avoid repeating the code and logic. I will use top 5 news view in several pages/controllers. I do not want to repeat data retrieval in every one of them. I already did separate a lot of logic and validation to business layer. The solution I'm after is RenderAction or UserControls as in classic ASP. I know i can use them in MVC as well, but... whats the point? I mean, if what i'm asking is too complicated or too absurd (reusable UI components), then MVC is definitely not for me, and I'd consider it seriously inferior to classic ASP.NET, because this requirement is really simple.
What you're asking is to basically not perform data access in the HomeController, this seems like a dogmatic approach. I would consider either using RenderAction from the Futures assembly (not sure what's wrong with it, I use it in a number of projects) or SubControllers from MvcContrib.
While I can understand the desire not to replicate functionality in multiple controllers, I don't understand the reluctance to have your Home controller interact with the DAL. I think the partial view is definitely the way to go. My solution to not replicating the functionality would be to push the code that generates the data for the various views into your business or data layer. You could then reference it from each of the required controller actions that use the partial views. Putting it in the business layer could isolate the controller from your data layer, if that's what you desire, but I still think it's the proper job of the controller action to obtain and provide the data to the view.
Another potential solution would be to populate the view generated by your Home controller via Ajax callbacks to the various controller actions that generate the required view components. The drawback to this is that it doesn't fail gracefully in the absence of javascript in the browser.
EDIT
Based on your clarification, I would suggest implementing a base controller that fills the ViewData for the shared controls in ActionExecuted (so that it's done only when the action succeeds). Derive your other controllers from the base controller when you want to inherit this behavior.
If you really don't want to use RenderAction, then the only other option you have is to load the necessary data pieces with action filters. Your home controller could then look like this:
public class HomeController : Controller
{
[RequireNews]
[RequireQuotes]
[RequireCart]
public ActionResult Index()
{
return View();
}
}
These action filters could be re-used where they are needed. You might also choose to place these on the controller class itself.