In the app I'm working on the administrator has the ability to select a customer to work with in a drop down list. Thing is that there are a large number of views that the administrator can go through and each time they'd have to select the customer again. In webforms this was rather easy... store it in a Session variable and reset it when another page loads.
MVC not so much. I seem to be stuck at the point where I pass this value to the view from the controller. We are storing the value in a Session variable which we access using a base controller like this:
MyController.CurrentUser.CurrentCustomerId
The question I can't solve is how I pass this value to a partial view. The customer selector tool is in a partial view which is added to pages that need it.
I thought of using the ViewBag, but that means that in every single action in my controllers that requires this value I would have to add:
ViewBag.CurrentCustomerId = CurrentUser.CurrentCustomerId;
And even then I'm not sure if the ViewBag data is carried through to the partial view. I think it is.
Seems like there should be a more efficient way to do this and still abide by MVC rules?
#Andre Calil provided a very good solution for carrying user information between controllers and views and I ended up using this approach.
See his answer at the following link: Razor MVC, where to put global variables that's accessible across master page, partiview and view?
Related
Is there any other way to pass value from one view to another or one controller to another apart from the methods below
Viewdata
TempData
Viewbag
or passing inline in page redirect code?
Any sort of communication between the views, excluding nested views i.e. partials, should go via the controller. That's kinda the whole point of MVC.
It sounds to me like you are sort of trying to get around the M/C part of the framework therefore it leads me to question is it the right tool for you to be using.
I am writing an ASP.MVC application and I know you can use authorisation filters on the cotrollers to control access to the pages but I am wondering what is the best approach to do if you want to control access to protected data within partial views.
From what I have read ASP.MVC doesnt offer this level of granularity.
This seems easily enough by adding the user permissions to the model as an attribute and then using a simple factory to decide if the view should be rendered or a blank view be returned.
So far I have
RenderPartial(PartialFactory.IsAllowedToRender("partialName", Model.Security), Model)
and the Factory either returns the view requested or a blank partial view.
Has anyone tried this before or knows why no one does this (apart from the extra effort)
We have done similarly with extension methods for HtmlHelper.
RenderPartialIfExists and so on. No shame in doing this if its something you are going to need frequently.
Doing it without the extensions as you have works as well, but its not as clean to read. Also, consider adding your security information to HttpContext.Current.Items, that way you don't have to pass it into the models all the time, and anything that needs to take advantage of it, helpers, controllers, etc have easy access to it, and you only have to fetch it at the beginning of a request.
How do I create a view in ASP.Net MVC 3 that defers creation/rendering of a portion of the view to another view/controller, without knowing at design time what view/controller will be deferred to?
I have a Dashboard view/controller that uses a Layout page. the dashboard view does most of the work of rendering the overall screen. However a certain placeholder section of the overall screen will differ based on business rules, configuration, user interaction etc. There are three separate plugin views/controllers that may need to be rendered in the placeholder section. How do I instruct the Dashboard view to render a specific plugin view once the Dashboard controller has determined which plugin should be visible. I have accomplished this already by putting flags in the Dashboard model and then having conditional logic in the Dashboard view call Html.RenderAction with the appropriate parameters based on the flags. This seems unsatisfactory and I would assume there is already a simple built in functionality for this kind of scenario, please advise.
Thank you
You are really asking "how do I dynamically render partial views who's identity is known at design time."
One can get there two ways, either through Html.RenderPartial or Html.RenderAction. And both have their place. If the main page "knows" enough to have the view data, then RenderPartial is your the better bet as it is a bit more efficient than RenderAction. If you only know, say, a unique identifier for your portal widget than RenderAction works because you've now got a fully capable controller method that can do things like go back to a database and render a view.
You could write your own htmlhelper and use that in your view instead of using the flags.
I'm building a site in ASP.NET MVC 2 that will allow for anonymous users and registered users. When a user is logged in, I want to display multiple pieces of information related to that profile on every page (i.e. hometown, favorite color, etc.). From a view perspective, I understand using Master pages and creating partials to keep it DRY.
However, where I am getting stuck is how do I pass this user information to the view for every page? I already have the relationships between database tables established (I'm using EF), so I can do this on an individual basis for each action through ViewData, but that's obviously ridiculous for every page on the site.
So far, my research has started to lead me down the path of creating a base controller and base view model that the other controllers and view models will inherit from. But I feel like I'm missing something obvious. Any pointers?
If you have your Master page use the RenderAction method, it can invoke controller actions for the various repetitive parts of your page, each of which can perform data access and render a partial view. That allows you to separate your view models while still displaying certain elements on all your pages.
This approach works great for us.
We use a base controller to store it in ViewData.
You could also use an action attribute on the controller rather than inheriting from a base controller.
You could create a base class for your models that contains the data that is display on every page.
Maybe I'm complicating this but you will enlight me for sure.
Imagine a page where a list is displayed. That list is paged.
I specify the list displays 30 items, therefore the controller returns my 30 items and the view renders the 30 items.
My question is: both the controller and the view need to know the 30 setting. Where should it be stored? Web.config? I'm thinking if sharing configs via web.config that are used across "layers" is a good practice...
Tks in advance
I don't think what you're describing is violating separation of concerns. By design data is shared across the layers of an MVC application, since the view has to get the data one way or another.
What you shouldn't do is have the view know how to get the data. In other words, your view shouldn't know where that "30" setting is coming from, so that you can change it in the future without changes necessary to the view.
Web.config is fine. Have you considered allowing the page length to be dynamic, perhaps based on a querystring value? (either way, you'll still need a default stored or hard-coded somewhere)
Also, I'm probably parsing words here, but you don't want your view to explicitly know of this setting (ie, accessing the web.config value directly). It should just iterate the list of items that the controller passes it, regardless of quantity.