Getting Started With Razor Pages In ASP.NET Core 2.0

Razor Page without Code Behind file.

Model Binding

We can bind the property directly with Razor Page using the [BindProperty] attribute. Property decorated with [BindProperty] attribute will automatically be available on the Razor page.

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;

namespace RazorPagesExample.Pages.Employee
{
    public class IndexModel : PageModel
    {
        [BindProperty]
        public Employee employee { get; set; }

        public void OnGet()
        {
        }
        public void OnPost()
        {
            var data = employee;
        }
    }
    public class Employee
    {
        public int ID { get; set; }
        [Required]
        [StringLength(50, ErrorMessage = "Name length should be 1 to 50.")]
        [Display(Name = "Employee Name")]
        public string Name { get; set; }
        [Required]
        [StringLength(255, ErrorMessage = "Address length should be 1 to 255.")]
        [Display(Name = "Address")]
        public string Address { get; set; }
    }
}

On the Razor page, just use the name of the property and bind the input control with this.

@page  
@model RazorPagesExample.Pages.Employee.IndexModel  

@{  
    ViewData["Title"] = "Employee Page";  
}  
<h2>@ViewData["Title"]</h2>  
<div class="row">  
    <div class="col-md-6">  
        <form method="post">  
            <div class="form-group">  
                <label asp-for="employee.Name"></label>  
                <input asp-for="employee.Name" class="form-control" />  
                <span asp-validation-for="employee.Name" class="text-danger"></span>  
            </div>  
            <div class="form-group">  
                <label asp-for="employee.Address"></label>  
                <input asp-for="employee.Address" class="form-control" />  
                <span asp-validation-for="employee.Address" class="text-danger"></span>  
            </div>  
            <button type="submit" class="btn btn-default">Add Employee</button>  
        </form>  
    </div>  
</div>  

Model Auto-Updating

A defined model with the Razor page will update automatically on the Code-Behind file. You don’t need to take care to bind your model with specific operations. Any changes inside the model data will be reflected in the Model itself.

You can see with the above code if you click on the “Add Employee” button and pass the correct data to avoid the error then data will bind with the model and reflect on the OnPost handler as follows. Here we are not passing the model as a parameter as we do in MVC.

Tag Helpers

As we all know tag helper is basically a feature of Asp.Net MVC and has been included with Razor Page. Now you can bind your data with Razor Page directly using Tag Helpers. As the following code shows, we are using so many Tag Helpers here like “asp-for”, “asp-validation-for” etc.

<form method="post">
    <div class="form-group">
        <label asp-for="employee.Name"></label>
        <input asp-for="employee.Name" class="form-control" />
        <span asp-validation-for="employee.Name" class="text-danger"></span>
    </div>
    <div class="form-group">
        <label asp-for="employee.Address"></label>
        <input asp-for="employee.Address" class="form-control" />
        <span asp-validation-for="employee.Address" class="text-danger"></span>
    </div>
    <button type="submit" class="btn btn-default">Add Employee</button>
</form>

Handlers

We use handlers to perform server-side operations like getting the data, and posting the data. These handlers are something like HTTP Verb we use in MVC like Get(), Post(), etc.

As a prefix, we use “On” with HTTP Verb in Razor Page which indicates as an event or handlers as OnGet() or OnGetAsync(), OnPost() or OnPostAsync(), etc.

Routing

As compared to MVC routing, Razor Page routing is very simple. We don’t have to write code manually for simple routing. All the pages inside the Pages folder will be called by file name after domain name.

• http://localhost:51068/index
• http://localhost:51068/about
• http://localhost:51068/employee/index

If you would like to pass parameters with a URL then you can add it with the @page directive as follows. Here you can see I am passing one ID which is an integer type.

@page "{id:int}"
@model RazorPagesExample.Pages.Employee.IndexModel
@{
    ViewData["Title"] = "Employee Page";
}

So, when you call the URL, you have to pass the ID which should be integer type as below URL.

http://localhost:51068/employee/index/1

Security

When we talk about security with Razor Page like a CSRF attack, we don’t need the manual code to protect our application from the outer world as we do in MVC. We don’t need to add an AntiRequestForgery Token or verify it. These tasks are done by Razor Page automatically internally.

Conclusion

So today, we have learned what Razor pages are in ASP.NET Core 2.0, and what their fundamentals are.

I hope this post will help you. Please put your feedback in the comments which helps me to improve myself for the next post. If you have any doubts, please do not hesitate to ask and if you like this post, please share it with your friends.