I have a product treeview that is referenced in multiple views and controller. The treeview items of the product treeview are loaded dynamically using AJAX and a public Action method.
Should i move the product treeview's logic and public action method to a shared controller such as SharedController? What do you recommend?
burnt1ce,
as ever, it depends... If you always use it via ajax (jquery or msajax?? [not that it matters much, but would allow you to add the appropriate tag to the question]), then I would be tempted to refactor it out to an html.helper with a few overloads to allow different product models to be loaded. (I would recommend using product interfaces, rather than concrete classes to allow for a variety of product sub-classes if required)...
If you ever need to load it in the context of a view, then you could keep it where it is and load it via an html.RenderAction() method.
this would certainly be my initial thoughts.
A ProductController with the action to retrieve your product data (returns JSON?)
Use a Partial View to spell out the Telerik View. I assume from that view you'll be making the ajax call to get the products then updating the treeview w/ that data?
<%= Html.Telerik().TreeView()
.Name("TreeView")
.Items(item =>
{
item.Add()
.Text("Mail")
.ImageUrl("~/Content/PanelBar/FirstLook/mail.gif")
.ImageHtmlAttributes(new { alt = "Mail Icon" })
.Items(subItem =>
{
...
Related
I'll explain my point:
The best practice is to create views strongly typed with a Model. You only can stronly type one Model.
If you need two models in a view you can created two views and use Partial Render, but it seems not to be the very best option.
Another approach is to create another type model that encapsulates the other pieces of the model what you need; this make much more sense for me.
Then, my question is, in a complex proyect when a page needs to communicate with all the models and they are not direct realted, developers create a type that encapsulates all the other things?
For non-related parts of your view, you may use Html.Action() to invoke an action that returns a partial view.
This way, the logic of the "area" will be encapsulated in its own action and/or controller.
Update: I don't know if it's really the best practice, but I prefer composition over complex views & view models. Even for related information, I prefer to break it to smaller partial views and child actions. As I see it, it has the following flexibility:
Ability to easily move some of the partial views/child actions to a layout page
Load the partial view asynchronously via AJAX query
Reduced controller action complexity and increased maintainability.
Better support for conditioned rendering
Separation of concerns
In (4) I mean that you can easily do the following without complicating your view model:
<div class="header">
#if (loggedInUser.ShowAds) {
#Html.Action("Header", "Ads")
}
</div>
Answering the question in your comment.
Considering twitter. There's the content pane and the users box on the left.
So here's our TweetsController:
public class TweetsController: Controller {
public ActionResult Index() {
var tweets = ...;
return View(tweets);
}
}
The Tweets/Index view may look like:
#model Tweet[]
<div class="leftPane">
#Html.Action("Index", "Users");
</div>
<div class="mainContent">
#foreach var t in Model {
#t.User - #t.Text
}
</div>
Note that the left pane just calls the Index action in UsersController to display the users list.
Here's how it may look like:
public class UsersController: Controller {
public ActionResult Index() {
var users = ...;
return PartialView(users);
}
}
And here's the partial view (Users/Index):
#model User[]
#foreach var u in Model {
<img src="#u.IconUrl"/> #u.Name
}
So what will actually happen, when the Tweets view will be rendered Html.Action will put the partial view returned by UsersController.Index in the left pane.
Of course you may move this logic into a layout if this behavior is common for a number of pages.
Hope that helps.
Then, my question is, in a complex proyect when a page needs to
communicate with all the models and they are not direct realted,
developers create a type that encapsulates all the other things?
Yes some of them do, and the name for these is ViewModels
This is a quite interesting question, in my opinion.
I have a strongly typed view using the WebForm view Engine, I don't know if changing to razor would solve my problem.
PROBLEM:
I have one view with a list of cars, so of type IList <Car>.
And I have a button "Create a new Car" that popups, the popup is a form that is hidded and you call a jQuery UI command $('formName').dialog() to popup it, this form has the attributes of the possible new car, so probably a new view with a strongly typed Car. After fill in the form the database should be populated with the new car, and the list of cars should be refreshed using Ajax.
The main problem is that I can't use HTML Helpers to IList <Car> and for Car at the same time.
Briefly: What is the strongly type for that view ? Is it possible to define two views and the other one call using pop-up? Changing it to Razor would solve my problem?
Best regards,
Tito Morais
Don't mix the views for listing the cars and creating a new car together.
For instance, you can make a popup that dynamically loads a "_CreateCar" partial view, using jQuery dialog or similar component. Then when the partial view is completed, reload the list view using another Ajax call.
Maybe not so much an elegant solution is to create a complex view model like:
class ListAndCreate
{
public IList<Car> AllCars {get;set;}
public Car NewCar {get;set;}
}
IMO this is correct since that one view is responsible for listing all cars and creating a new one. Now, I'm assuming that your NewCar has values coming from your controller or something, where you need to pass a model to your view.
The other approach, that #Jonas mentions is also correct and more unitized. You could create a partial view _CreateCar with type Car, render it with Jquery/Ajax to load it into a dialog/popup and have the form POST to a Create(Car c) method in your controller.
I'm stuck! I'm under the impression that the _layout.cshtml file is used for MasterPage-like content. Everything there is rendered on every page. Naturally, I want to write the code for rendering my sidebar menu in that file.
I want to dynamically display a list of Categories from my DB, but I'm having a problem with passing the actual model of categories to Layout.cshtml since it seems no controller actually touches it.
Any suggestions?
Otherwise please tell me how to approach this problem. I've been wracking my brain for the past three days and still no elegant solution.
I need to:
Dynamically fetch a list of Categories from the DB.
Display this list of Categories on every single view. (Hence the use of _layout.cshtml)
Elegantly handle each different categories click.
I'm at my wits end. :P How would you solve this?
_layout.cshtml
#if(isSectionDefined("Categories"))
{
<div id="sidebar">
#RenderSection("Categories", required: false )
</div>
}
index.cshtml
#section Categories {
<ul>
<li>Category One</li>
<li>Category Two</li>
<li>Category Three</li>
</ul>
}
see this : http://weblogs.asp.net/scottgu/archive/2010/12/30/asp-net-mvc-3-layouts-and-sections-with-razor.aspx
Any viewmodel that you pass to your view is automatically available within your master page. If you do not use RenderAction/Action which is the best approach, then you must create the necessary master page data in every action and add it to viewdata - either by having a common base class for your strongly typed viewmodel that contains all master page data or by using the viewdata dictionary.
I would strongly recommend that you go down the html.action approach though. In this way, you have a totally separate controller action for dealing with your list of categories. This action can retrieve the neccesary category data and return the categorylist usercontrol as a partialview and you will not have to worry about polluting all your other actions with this data.
As I see it, ViewData (and its relatives like ViewBag, Model, etc.) is meant for the specific current view. Your _Layout.cshtml is not specific to the current view; and it would be awkward if EVERY controller would have to pass the categories data in addition to whatever else data it needs to pass for the view.
Instead, what I do, is provide a static method in one of my helper classes that retrieves the categories from the DB. I also do some caching there, so that I do not have to hit the DB on every single request. The _Layout.cshtml then simply calls this static method. Simple and elegant.
If you wish, you can bring this out to a partial view, make it a helper method, whatever.
One note of caution though - my custom error view also uses the same _Layout.cshtml, and if the DB goes down, you get an exception trying to display the exception. ASP.NET MVC is smart enough to detect this and abort processing, but you're left with a nondescript default error page. What I did was to place try...catch statements around these dangerous calls, which quietly ignore the exception if the current page is the error view.
I've achieved something similar by having my ViewModels implement an Interface which has members that contain the menu data. In my action method I set that data. Then in my view I check to see if my view-model implements that inteface, pull the menu data out and render the menu (in a partial view actually)
I have a user control which shows list of latest announcements. This user control would be used in almost 90% of my pages. Now my concern is how to pass data to this user control for latest announcements.
My first approach is to make a base controller and in Initialise method I pass data to user control via ViewBag/ViewData. All my other controllers derive from this base controller. This looks nice but my concern is that it may become an overkill for some simple solution existing already out there. Also I would need to make sure that no controller ever fiddles with my Viewdata/Viewbag data meant for my usercontrol.
Please let me know if this is correct way of proceeding ahead or there exists some better solution.
Thanks
Assuming you have a "user control" (you should try to refer to them as partial view's in MVC) that looks like this:
<%# Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<IEnumerable<Announcement>>" %>
This means your partial view expects a list of Announcement objects.
Now, the question is - where are you rendering this partial view?
You could be doing it from a master page, you could be doing it from a view, or you could be doing it from another partial view.
Either way, the code to render the partial needs to look like this:
<% Html.RenderPartial("LatestAnnouncements", announcements) %>
But - where do you get the announcements from.
Assuming you have a Repository/DAL/helper method to get the latest announcements - i think you should have the ViewModel's you require inheriting from a base ViewModel:
public class AnnouncementViewModelBase
{
protected IEnumerable<Announcement> GetAnnouncements()
{
// call DAL
}
}
Then any master/view/partial that needs to render the latest announcements partial should be bound to a ViewModel which inherits from that base view model.
In the cases where the master/view/partial is not strongly-typed (e.g dynamic view), you can stick it in the ViewData. But if you have organized your view's correctly this shouldn't be required.
Is this the kind of thing you're after? How to pass data from view to UserControl in ASP.NET MVC?
You should use RenderAction in this kind of scenario, so that you do not have bother to pass the required data in each action method of your controllers.
I think the best way would be to use #Html.Action. This would allow me to call my actions dedicated to my usercontrols data and I can call it from anywhere.
I'm wanting to create a page that allows the users to select how they would like to view their data - i.e. summary (which supports grouping), grid (which supports grouping), table (which supports grouping), map, time line, xml, json etc.
Now each layout would probably have different use a different view model, which inherit from a common base class/view model. The reason being that each layout needs the object structure that it deals with to be different (some need hierarchical others a flatter structure).
Each layout would call the same repository method and each layout would support the same functionality, i.e. searching and filtering (hence these controls would be shared between layouts). The main exception to this would be sorting which only grid and table views would need to support.
Now my question is given this what do people think is the best approach.
Using DisplayFor to handle the rendering of the different types?
Also how do I work this with the actions... I would imagine that I would use the one action, and pass in the layout types, but then how does this support the grouping required for the summary, grid and table views.
Do i treat each grouping as just a layout type
Also how would this work from a URL point of view - what do people think is the template to support this layout functionality
Cheers
Anthony
Conceptually, the View is the part of an MVC web app that is responsible for handling the displaying of data. So, if you want to display data in different ways, it seems most logical that each "display" has its own corresponding aspx View.
All of the View Models can inherit from the same base model. So, for example, we might have four models and three views:
public abstract class BaseViewModel {}
public class GridViewModel : BaseViewModel {}
public class TableViewModel : BaseViewModel {}
public class SummaryViewModel : BaseViewModel {}
GridViewPage<GridViewModel>
TableViewPage<TableViewModel>
SummaryViewPage<SummaryViewModel>
Each of the views can have different stylehsheets and javascript files attached, so you should be able to use DisplayFor if you'd like, or you can create the layout by hand.
As for the controller, you can create one action method that returns any of the three views, or you could create three separate ActionResults, one for each view. Here's the "monolithic" ActionResult:
public ActionResult PageViewResult(string pageType)
{
switch (pageType)
{
//define your cases, return your views and your models
//make sure to set a default
}
}
You can format the routes however you see fit. For example, with the above "monolithic" ActionResult, we could create the following route in our Global.asax file:
routes.MapRoute(
"FormattedViewPage", // Route name
"View/Page/{pageType}", // URL with parameters
new { controller = "ViewPageController", action = "PageViewResult", pageType = "grid" } // Parameter defaults
);
Hope this helps. Let me know if you have any questions.
First of if it's the same data then I would try to use the same model for all the views but either use different css or different aspx pages/controls for rendering the model depending on how the user wants to view the data.
Also you may want to look into how much of this can be done in JavaScript, it all depends on how rich you want the user experience to be.