Partial View in ASP.NET

Partial View, .NET, ASP.NET, Razor syntax,

Partial View in ASP.NET 

A partial view in ASP.NET is a reusable view component that can be embedded within other views. It's a way to break down a larger view into smaller, more manageable pieces, and it can help you to reduce duplication of code and make your application more modular and maintainable.

A partial view can be created using the same Razor syntax as a regular view, and it can be used to display data or perform any other action that a regular view can do. The main difference is that a partial view doesn't have its own layout, and it's typically used to render a specific portion of a page.

To use a partial view in your application, you can call the Partial method from within another view and pass in the name of the partial view as a parameter. For example,

// Calling Partial View in Page with Model
@await Html.PartialAsync("_MyPartialView", myModel)

// Calling PartialView
//This method renders a partial view as a string and includes the result directly in the output.
<div>
    @Html.Partial("_Employee")
</div>

//This method is similar to Html.Partial(), but it writes the output directly to the response stream instead of returning a string.

<div>
    @Html.RenderPartial("_Employee")
</div>

//Html.PartialAsync() - This method is an asynchronous version of Html.Partial(), which can be //useful for rendering partial views that take a long time to generate.
<div>
    @{ await Html.PartialAsync("_MyPartialView"); }
</div>

//Html.RenderPartialAsync() - This method is an asynchronous version of Html.RenderPartial(), //which can be useful for rendering partial views that take a long time to generate.

<div>
    @{ await Html.RenderPartialAsync("_MyPartialView"); }
</div>

Partial views can be used in a variety of scenarios, such as displaying a list of items, rendering a form, or displaying a sidebar on a page. By using partial views, you can create a more modular and flexible architecture for your application, making it easier to maintain and update over time.

Advantage Partial View 

• Reusability- A partial view can be reused in multiple views, which can save you time and reduce duplication of code.
• Separation of concerns- By breaking down a larger view into smaller partial views, you can separate different parts of the view into their own logical units, making it easier to manage and maintain your code.
• Modularity- Using partial views can make your application more modular, which can make it easier to add new features or update existing ones.
• Performance- By using partial views, you can optimize the rendering of your views and reduce the amount of HTML that needs to be sent to the browser. This can lead to faster page load times and a better user experience.
• Flexibility- Partial views can be used to render different types of content, such as lists, forms, or navigation menus. This makes it easier to create dynamic, responsive user interfaces that can adapt to different screen sizes and device types.

How to use the Partial Views in ASP.NET MVC Application to show Notification Message?

Step 1. Create a partial view named _Messages.cshtml that displays the messages.

@if (TempData["SuccessMessage"] != null)
{
<div class="alert alert-success">@TempData["SuccessMessage"]</div>
}

@if (TempData["ErrorMessage"] != null)
{
<div class="alert alert-danger">@TempData["ErrorMessage"]</div>
}

@if (TempData["WarningMessage"] != null)
{
<div class="alert alert-warning">@TempData["WarningMessage"]</div>
}

Step 2. Set TempData in the controller action.

// Success Case
public IActionResult Index()
{
            TempData["SuccessFlag"] = "Success";
            TempData["SuccessMessage"] = "The operation was successful.";
            return View();
}

// Warning Case
public IActionResult Index()
{
            
            TempData["WarningFlag"] = "Warning";
            TempData["WarningMessage"] = "Warning";
            return View();
}

//Error Case
public IActionResult Index()
{
            
            TempData["ErrorFlag"] = "Error";
            TempData["ErrorMessage"] = "Error";
            return View();
}

Step 3. Include the partial view in the main view where you want to display the messages.

<div>
        @if (TempData["SuccessFlag"] != null && TempData["SuccessFlag"].ToString() == "Success")
        {
            await Html.RenderPartialAsync("_Messages");
        }
        else if (TempData["WarningFlag"] != null && TempData["WarningFlag"].ToString() == "Warning")
        {
            await Html.RenderPartialAsync("_Messages");
        }
        else if (TempData["ErrorFlag"] != null && TempData["ErrorFlag"].ToString() == "Error")
        {
            await Html.RenderPartialAsync("_Messages");
        }

    </div>

Summary

Overall, partial views can be a powerful tool for creating more modular, maintainable, and flexible applications. By breaking down larger views into smaller pieces, you can create more reusable code and make it easier to manage and maintain your application over time. Partial views are a powerful tool in ASP.NET MVC for creating modular, reusable UI components that simplify development and maintenance

Thank you for reading, and I hope this blog post has helped provide you with a better understanding of the Partial View in Asp.net Mvc