[ASP.NET Core] - Razor Page - Let's think straight
When you need to build a website with the pages you need very quickly, without worrying about complex issues like patterns, security or scaling, Razor Page is the answer
1. Requirements
- .NET Core 2.0 or later
- Visual Studio Code
- A quick read on Razor Page
2. The development pattern
If you are a long-time ASP.NET warrior, you’re surely familiar with the MVC pattern, short for Model-View-Controller. With Razor Page you meet a completely new and extremely simple pattern (so simple there is nothing to learn)
The MVC pattern
If you want to get familiar with the MVC pattern, you can read [ASP.NET for Beginner] – Part 1 – MVC
The Razor Page ‘pattern’
3. MVC’s problems
3.1. Fat Controller
Say you have a controller handling tasks related to money transfers between accounts, call it TransactionController
There are 4 basic operations on a row of data: Create-Read-Update-Delete — so far so good, no problem
Bam, you also want to handle phone top-ups, paying electricity, water and internet bills => add methods like NapTheCao, TraTienDien, TraTienNuoc, TraTienInternet. 2 weeks later you want a few more features, all related to transactions.
Over time TransactionController gets longer and longer, and it has officially earned the name Fat Controller.
3.2. Nesting levels
The MVC pattern gives you a folder named Controllers to hold all your controllers. This corresponds to 1 level in the URL
With the transaction example above, your URL looks like: domain/transaction/create
What if you want one level deeper, like domain/transaction/phones/create? You have to either customize the route or create an Area named Transaction and split the related functions into separate controllers.
3.3. Duplicate
For any form, in the mvc pattern there must always be 2 actions matching the 2 verbs, Get and post, and people usually give these 2 actions the same name so they’re easy to tell apart from the other features in the same controller. This is sometimes inconvenient, and you are required to declare the [HttpGet] and [HttpPost] attributes
4. Razor Page Coding conventions
Like MVC, Razor Page also has some coding conventions
Conventions
MVC
RAZOR PAGES
Default View
Index.cshtml
Index.cshtml
return default view
return View();
return Page();
Http Verbs
[HttpGet]
[HttpPost]
OnGet();
OnPost();
Binding data
ViewModel
[BindProperty]
Generate Link
Url.Action(…)
Url.Page(…)
multiple action for form submit
Not built-in
asp-page-handler=“TestHandler”
OnTestHandler()
5. The future is now?
Razor Page, in my judgment, only fits small and medium projects with views that are simple in logic.
As of .NET CORE 2.0, Razor Page still doesn’t support some features MVC has:
- IActionFilter
- Output Cache
- The IgnoreAntiforgeryToken attribute (you can read this github issue to learn how to disable it entirely)