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I have an MVC 5 site with adminlte template. It's work fine. Now I need pass to some data to _layout page. I need pass to _layout page same info as number of alert, number of email, alert list ecc. I read same document about BaseController where do this operation, i.e. read this data and put in a model, or create an abstract model and put this info into. But is not possibile create this model one time (i.e. on user login controller) and share it in all request without re-create it every controller call? Pratically, as a global singleton variabile. Thanks.

Andrea Merlin
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  • so you basically want a default view model which contains repeated porperties like email & info...?? & include this view model in all the entity classes so that the same properties dont have to be created again & again.. am i correct ? – Rohit Kumar Oct 20 '17 at 07:42
  • Yes. Same properties. If possibile I want generate this model only one time. – Andrea Merlin Oct 20 '17 at 07:51

2 Answers2

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Looks like a good usecase to use a ChildAction which can be called from the layout view.

So start by creating a view model to represent the data

public class AlertVm
{
    public int EmailCount { set; get; }
    public int NotificationCount { set; get; }
}

Now create an action method which creates an object of this, set the values and pass to a partial view

[ChildActionOnly]
public ActionResult Alerts()
{
    var vm = new AlertVm {EmailCount = 4, NotificationCount = 2};
    return PartialView(vm);
}

Now your Alerts.cshtml view, which is strongly typed to our view model, you can render whatever you want.

<div>
    <p>@Model.EmailCount emails</p>
    <p>@Model.NotificationCount notifications</p>
</div>

And this action method can be invoked from the _Layout.cshtml view.

<div>@Html.Action("Alerts", "Home")</div>

With this approach, you do not need worry about the creating a view model for every single action. (Ex : Your about page which does not need a view model usually)

Shyju
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  • This is a good solution! Thanks. The problem is that in ActionResult I need to access db data (i.e. EmailCount is a entityFramework call). Every page have same delay. – Andrea Merlin Oct 20 '17 at 15:08
  • what is the problem with that ? Just query it using entity framework. – Shyju Oct 20 '17 at 15:12
  • There are no problems. But, do query one time will be the best solution. Try to use Session variable. Thanks – Andrea Merlin Oct 23 '17 at 15:25
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Yeah you can create a base view model & make all the model inherit it 

public class MyModel
{
    public MyBaseClass BaseClass { get; set; }
}

public abstract class MyBaseClass
{
    public virtual string MyName
    {
        get
        {
            return "MyBaseClass";
        }
    }
}

public class MyDerievedClass : MyBaseClass
{

    public int MyProperty { get; set; }
    public override string MyName
    {
        get
        {
            return "MyDerievedClass";
        }
    }
}

only problem is ..the default CreateModel process doesnt register this deafult view model so global.asax is where you tweek it ..

Here is a good explanation

Rohit Kumar
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