ASP.Net MVC reusable form as RenderAction or RenderPartial - asp.net-mvc

I'm looking for a best practice for embedding a form on multiple pages as a partial view.
I have a contact form I'm looking to embed on multiple pages on a site. Usually, the form would be on a contact page and the contact model could be the model for the view and use data annotations for validation. However, the view is already strongly typed.
How can I create a reusable form in a partial view and embed it on the page? I'm using N2 on the site, so the pages have to already have a strongly-typed model, but I would be open to extending those objects.

Personally, I recommend using for Html.RenderAction() for cross-cutting concerns such as these.
The handler for your contact form is going to need to exist independently of the page your are currently viewing so you are left with 3 options:
Manually add it to the response of
the current action
Manually add it to the response of
the current controller by way of a
base controller that modifies the
ViewState or ViewModel
Call the RenderAction()
HtmlHelper inside of the current view
Of these 3 options, while the third is technically more costly than 1 and 2 (because it initiates a brand new request), it is also the most maintanaible solution. By calling RenderAction() you have the advantage of being able to completely isolate your contact form from the rest of the view and thus you won't have to worry about hacking it into the current controller responses.

Use RenderPartial if data model for partial view is already in main view's model, in other case use RenderAction (then the action of the partial view will create its view model itself).

Related

Using #Html.Partial In Sitecore

I would like to use the generic razor helper function Html.Partial to render views that have common html in them.
For instance, I have two views set up in Sitecore Payment Information.cshtml and Agent Payment Information.cshtml. These are rendered using the Sitecore rendering engine. Both of these views have very similar html in them that I would like to put in razor views not set in Sitecore and call them with #Html.Partial as appose to #Html.Sitecore().Rendering() as the latter forces me to set up a view and model in Sitecore which I am not sure is necessary.
My question is, is there anything that Sitecore does behind the scenes that makes it necessary to usethe #Html.Sitecore().Rendering() helper method instead of the #Html.Partial() helper method? Everything seems to work fine and I believe the entire view should get cached since the #Html.Partial call is nested inside either the Payment Information view or the Agent Payment information view set up in Sitecore.
Thanks in advance.
I have Html.Partial working in an MVC solution using Glass for ORM. There are two ways I've used this, one where the assumed model being passed to the partial is the same as the parent rendering and another where we create the model on the fly.
Assumes parent rendering model is passed:
#Html.Partial("~/Views/Components/MyPartialView.cshtml")
Instantiates a new model that is passed in:
#Html.Partial("~/Views/Components/Navigation/SecondaryNavigationRendering.cshtml", new SecondaryNavigation())
The parent view will need to have a mapped model in Sitecore. The secondary view does not have a mapped model in Sitecore but is typed to receive the model being passed (so in my first example that would be my IBasePage model, in my second it would be my SecondaryNavigation model).
Hope this helps.

Using MVC Partial View's own model instead of its parent's

I need to populate a list box in a partial view, using ASP.NET MVC4.
Can Partial View have its own #model, as opposed to taking a model from its parent as described here?
I can populate my dropdown box using a separate AJAX call to another MVC controller (i.e. not parent page/url) as discussed here, but the resulting syntax is a bit more clumsy; furthermore, an additional endpoint is exposed to the outside world.
Yes - you can call partial view with any model you like. There is no requirement that data somehow comes from current model.
#Html.Partial("PartialView1", new MyOtherModel(42))

Developing ASP.NET MVC web applications the right way

I'm starting to develop a new ASP.NET MVC application, and I'd like to make sure that my understanding about the way of developing applications under MVC pattern is correct.
Question 1: Suppose that I have some main views (MainView1, MainView2, ...) with some partial views in it (PartialView1, PartialView2, PartialView3, ...). From what I have understood about MVC, I should define a Model for each view. e.g. I have to define PartialModel, PartialModel2, ... and also define my main models which are containers of the partial models which have been used in them:
public class MainModel1
{
public PartialModel1 Partial1 {get;set}
public PartialModel2 Partial2 {get;set}
public PartialModel3 Partial3 {get;set}
}
This way when I want to redirect to MainView, I can initialize the models used in that view by using this Model. Is my understanding of MVC correct? Or should communication between Views and Models be in another form in MVC?
Question 2: If the above is correct, Then suppose I have a partial view in some of my main view pages. This partial view has a submit button which calls an action method. This action method should somehow return the main page's view with the right viewmodels for views. Is there any recommendation about how to get/set viewmodels of other views in a partial view's action?
Thanks.
You understanding is correct. Each view (no matter whether it is main or partial) should have a corresponding view model (unless in the very rare case where this view contains only static html of course). And following this logic a main view that has to render other partial views will have a view model which itself will have reference (maybe as properties) to view models that are required by those partial views.
There is another technique which is using the Html.Action helper. In this case the partial is rendered through another controller/action than the main one. So you don't need to reference the partial view model in the main view model. They will be completely distinct. Take a look at the following blog post to learn more about Html.Action.
Your understanding is perfectly fine. This is what you can also refer to ViewModel in Asp.net MVC.
So, What basically is an Asp.net MVC ViewModel ?
In ASP.NET MVC, ViewModels allow you to shape multiple entities from one or more data models or sources into a single object, optimized for consumption and rendering by the view. The below image illustrates the concept of a ViewModel:
The purpose of a ViewModel is for the view to have a single object to render, alleviating the need for UI logic code in the view that would otherwise be necessary. This means the only responsibility, or concern, of the view is to render that single ViewModel object, aiding in a cleaner separation of concerns (SoC). Concerns are distinct aspects of the application that have a particular purpose (i.e., concern), and keeping these aspects apart means your application is more organized, and the code more focused. Putting data manipulation code in its own location away from the view and controller, enforces SoC.
Using ViewModels in MVC for finer granularity and better SoC leads to more easily maintainable and testable code. Remember, unit testing is about testing small units.
Along with better coding practices, there are many business reasons demonstrating why you might consider using ViewModels:
Incorporating dropdown lists of lookup data into a related entity
Master-detail records view
Pagination: combining actual data and paging information
Components like a shopping cart or user profile widget
Dashboards, with multiple sources of disparate data
Reports, often with aggregate data

ASP.NET MVC 2 Submitting from partials in different views

If I have a partial that is used in multiple views that submits to its own dedicated action, then how do I know which view it has come from so I can go back to that view?
I think it's answered here: Retrieve the current view name in ASP.NET MVC?
Just to clarify - How do you mean 'so you can go back to that view'
If you use ajax forms ie Ajax.BeginForm for each of those partial views, they will all automatically handle their own psots to the url (hence controller) and can live peacefully in the parent view no matter which view it is.
if model validation happens, then you will see it in those partial views and modelstate will repopulate the posted values into the model for the user to 'fix'

Populating the model for a shared view, embedding a shared view within another view

I'm trying to embed a small view snippet that steps through a model fragment that works fine when I embed it in a single controller and pass it to a view like so;
Controller:
return View(_entities.formTemplate.ToList());
View:
http://www.pastie.org/666366
The thing is that I want to be able to embed this particular select box in more than just this single action / view, from the googling I've been doing this appears that it should go into a shared view, but I'm not clear then on how I could populate the model within that view from the controller? (or maybe I'm completely missing the purpose for shared views?)
In the other MVC framework I'm accustomed to working with there is the concept of a filter where you can call code before or after any action and mod the model as it passes the controller and goes to the view, is such a thing possible in .net mvc?
Any assistance appreciated.
You'll want to use the HtmlHelper method DropDownList() in order to create a input:
<%= Html.DropDownList("id", new SelectList(formBuilder, "ID", "Name")) %>
You probably want to use a ViewUserControl here.
You have a couple of options if you go that route. If it's model data that is easily available, recreate it at the call site of your RenderPartial like so:
<%=Html.RenderPartial("ViewName", new ModelData())%>
If it's data that is dependent on the current model data, then you'll need to pass that data somehow to your partial view.
ASP.Net MVC also has the concept of before/after controller actions. You decorate your controller method with an Attribute that derives from ActionFilterAttribute. In there, you have access to OnActionExecuting and OnActionExecuted.

Resources