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.)
Related
I am developing a marketplace application which is supposed to have different products and vendors which are mapped to different cities.
The idea is that I need to store the CurrentCity in context so that I can use it to construct urls, filter data, fetch delivery areas etc.
e.g.
www.mywebsite.com/cityA/listings
www.mywebsite.com/cityB/listings
www.mywebsite.com/cityA/cart
www.mywebsite.com/cityB/cart
Something like the MoonPig website (https://www.moonpig.com/uk/Gift/Flowers/)
Currently, I am passing the city as a parameter in almost all the controller methods and also storing it in a cookie.
Alternatively, I am also thinking of creating a BaseController and possibly inject it in the OnActionExecuting(ActionExecutingContext context).
But the problem with the first approach is that all the Action methods need to have "city" as a parameter and I need to have it in context for doing something like
#Url.Action("Index", "Listings", new {city = cityName})
If I use the second approach, then I don't think I'll get the urls which have city in them.
I am ideally looking for a solution with which I can inject a city parameter as Base route / segment in the MVC RouteDictionary so that all the Urls are generated accordingly (with #url helper).
Is this possible or is there a better way to tackle this problem?
Would really appreciate if someone can show me a direction.
But the problem with the first approach is that all the Action methods need to have "city" as a parameter
This assumption is incorrect, since MVC automatically passes values from the current context when generating URLs, so there is no need to explicitly pass city as long as it is configured in the route and present in the URL. See this answer for how you can utilize this behavior for localization, which is similar to what you are doing.
I have to make vanity urls for an already existing site. The requirements are:
The existing controllers are a kind of hierarchical structure and can't go away or be overridden in any way. Examples: domain.com/Dog/vanity and domain.com/Cat/vanity.
Keep existing actions. Any existing actions must take priority so that the page for that action is not stomped on by the vanity url.
take future pages and actions into account so that the above requirement is met (a new vanity url is ignored and the action/view executed instead)
To date, I have tried various solutions with routing that allow me to have domain.com/vanity which is nice but the marketing guys don't like because of the different departments within the company. I've tried routing which will override the existing actions and treats them all as vanities (also not feasible). I've a solution in place that programmatically deals with the url that was requested and redirects to a page that actually exists but this is not scalable in any way.
So far, I know that the vanity portion can be treated as a parameter to the action so that I can fire off the default page in the route (Index) but this is, so far, doesn't preserve the structure.
TL;DR: I need to have a solution that allows for domain/controller/vanity structure while also allowing domain/controller/action
Using AttributeRouting for MVC4 you can accomplish a working solution until you ramp up the replacement project. It'll allow you to keep existing routes while adding new, custom ones with little impact.
[Route("my-vanity/is-cool/post/{id}")]
public ActionResult Index(int id)
{
}
The important part is to remember priority, so you write routes that don't overwrite/are overwritten by existing routes. You can steer this to some degree with properties on the attribute. Below is just an example that will put the added route last in priority for the entire site.
[Route("my-vanity/is-cool", SitePrecedence = -1)]
public ActionResult Index()
{
}
ASP.NET WebApi2 have built in support for attribute routing. With it you can define URL's in whatever way you like (instead of following the /controller/action pattern)
http://www.asp.net/web-api/overview/web-api-routing-and-actions/attribute-routing-in-web-api-2
I have a client who wishes to use a URL naming convention along the lines of:
/{subjectarea}/{subject}/{action}
Which is fine - this works brilliantly, with one controller per subject area, and having the action after the id (subject) is no issue at all.
However, it then gets complicated, as the client then wants to further continue the hierarchy:
/{subjectarea}/{subject}/{action}/{tightlyrelatedsubject}/{tightlyrelatedsubjectvariables}/{tightlyrelatedsubjectaction}
I have a controller for the tightly related subject (its just another subject area) which handles all of the admin side, but the client insists on having the public view hung off of the parent subject rather than its own root.
How can I do this while avoiding breaking the entire principals of MVC, and also avoiding re-implementing a ton of ASP.Net MVC provided functionality in my subject area controller just to be able to handle the related subjects from that same controller?
Is it possible to somehow call the related subjects controller from within the parent subject controller, and return the resulting view (as this would keep the separation of functionality for the subjects to their own controllers)? If that is possible, it would solve a heck of a lot of issues with this.
Here is the solution which solves my given issue - hope it solves someone elses.
As mentioned in my comment to Robert Harvey, all I actually need is another route which doesn't use the first two or three components as the controller, action and id, but instead takes those values from later on - if you hang this off of a static value in the route as well, its much easier to do.
So, here is the url I decided on to simplify the route:
/{subjectarea}/{subject}/related/{tightlyrelatedsubject}/{tightlyrelatedsubjectvariables}/{tightlyrelatedsubjectaction}
The route which satisfies this URL is as follows:
routes.MapRoute(
"RelatedSubjects",
"{parentcontroller}/{parentsubject}/related/{controller}/{id}/{action}",
new { controller = "shoes", action = "view", id = "all" }
);
On the subsequent controller action, I can ask for parameter values for parentcontroller and parentsubject so I can filter out the related item to just be specific to the given parent subject - problem solved!
This route needs to be above the ones which just deal with the first two values, otherwise you run the risk of another route map hijacking the request.
I could do this entirely without the /related/ static portion as the route could easily match on number of values alone, and infact I may indeed do so - however, I consider it better for later administration if there is a static item in there to confirm the use of the route.
I hope this helps someone!
One way you can do it is specify a wildcard route (notice the asterisk):
routes.MapRoute("subjects", "{action}/{*path}",
new { controller = "Subjects", action = "Index" });
This allows the controller to receive the entire path string after the action.
You can then obtain the hierarchy of subjects in the controller method like so:
string[] subjects = path.Split('/');
Once you have that, you can do anything you want, including dispatching different subjects to different handling methods for processing.
Should we move logic that supposes to be in Controller (like the data to render the partial view) to ActionFilter?
For example, I'm making a CMS web site. There should be a advertisement block to be rendered on several pages but not all the pages. Should I make an ActionFilter attribute like [ShowAd(categoryId)] and decorate the action methods with this attribute?
The implementation of this controller would include service calls to retrieve information from database, buildup view models and put in the ViewData. There would be a HtmlHelper to render the partial view using the data in ViewData if it exists.
That just seems yucky to me.
When I'm trying to figure out whether I need an ActionFilter, the first question I have is, Is this a cross-cutting concern?. Your particular use-case doesn't fit this, at first blush. The reason is, is that an ad is just another thing to render on a page. There's nothing special about it that makes it cross-cutting. If you replaced the word 'Ad' with 'Product' in your question, all the same facts would be true.
So there's that, and then there's the separation of concerns and testability. How testable are your controllers once you have this ActionFilter in place? It's something else you've got to mock out when testing, and what's worse is that you have to mock out those dependencies with every controller you add the ActionFilter to.
The second question I ask is, "How can I do this in a way that seems most idiomatic in the platform I'm using?"
For this particular problem, it sounds like a RenderAction and an AdController is the way to go.
Here's why:
An Ad is its own resource; it normally isn't closely tied to anything else on the page; it exists in its own little world, as it were.
It has its own data-access strategy
You don't really want to repeat the code to generate an Ad in every place you could use it (which is where a RenderPartial approach would take you)
So here's what such a beast would look like:
public AdController : Controller
{
//DI'd in
private AdRepository AdRepository;
[ChildActionOnly]
public ActionResult ShowAd(int categoryId)
{
Ad ad = Adrepository.GetAdByCategory(categoryId);
AdViewModel avm = new AdViewModel(ad);
return View(avm);
}
}
Then you could have a custom partial view that is set up around this, and there's no need to put a filter on every action (or every controller), and you don't have try to fit a square peg (an action filter) in a round hole (a dynamic view).
Adding an Ad to an existing page then becomes really easy:
<% Html.RenderAction("ShowAd", "Ad" new { categoryId = Model.CategoryId }); %>
If your ad system is simple enough, there is no reason you could/should not use an action filter to insert enough info into the view data to generate the ad in your view code.
For a simple ad system, say.. a single ad of a specific category shows up in the same place in the layout on every page and that's it, then there is no real argument of a better way except to prepare for future changes to the system. While those concerns may be legitimate, you may also have it on good authority that requirement will never change. But, even if requirements do change, having wrapped all the code that generates ads in one place is the most important aspect and will save you much more time up front than a more robust solution might. Obviously there are more than a few ways to wrap this code in a single place.
As for the way you are choosing to do it, I would keep your action filter cleaner to only have it insert the category into the view data and have all the magic happen inside your html helper which would take the category in as a parameter. Building up view models to shove into the view data is going to require a bit of extra work, and put code all over the place when it doesn't need to be there. Keep it simple and do all of the html generation inside of the html helper which is responsible for...building html.
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.