I am creating a Vazor (VB.NET Razor) using XML literals supported in VB.NET. I generate a string containging Html code but it needs further processing to resolve paths, handle asp- attributes, do ant encryption or authentication … etc. All this work is already done in Razor, so I don’t want to reinvent the wheel. I want to know the part of the Razor doing this to deliver my HTML code to and get the work done.
I create a Class for each view, that implements IVazor Interface. The vbxml code is written in teh Vazor method. This is how it looks like:
Public Function Vazor() As XElement Implements IVazor.Vazor
ViewBag.Title = "Vazor Sample"
Return _
<p>
<h3> Browse Students</h3>
<p>Select from <%= students.Count() %> students:</p>
<ul>
<%= (Iterator Function()
For Each std In students
Yield <li><%= std.Name %></li>
Next
End Function)() %>
</ul>
<script>
var x = 5;
document.writeln("students count = <%= students.Count() %>");
</script>
</p>
End Function
I made a proof of concept here: https://github.com/VBAndCs/VB.NET-Razor
Note: I changed the VBRazor to Vazor but didn’t upload this yet.
I want to complete this work, but I need help. My Vazor delivers a string containing HTML code without any C# ot VB code, so it differs from Razor in three things:
1- no need to locate any chtml file.
2- no need to combine view parts (layout, sections, etc) because mu view classes take care of that (I didn’t complete this yet. I only cobine the layout for now)
3- no need co compile the View or evaluate any thing.
So, I deliver html code like this:
<html>
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>@ViewBag.Title - WebApplication1</title>
<environment include="Development">
<link rel="stylesheet" href="~/lib/bootstrap/dist/css/bootstrap.css" />
</environment>
<environment exclude="Development">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.1.3/css/bootstrap.min.css" asp-fallback-href="~/lib/bootstrap/dist/css/bootstrap.min.css" asp-fallback-test-class="sr-only" asp-fallback-test-property="position" asp-fallback-test-value="absolute" crossorigin="anonymous" integrity="sha256-eSi1q2PG6J7g7ib17yAaWMcrr5GrtohYChqibrV7PBE=" />
</environment>
<link rel="stylesheet" href="~/css/site.css" />
</head>
<body>
<header>
<nav Class="navbar navbar-expand-sm navbar-toggleable-sm navbar-light bg-white border-bottom box-shadow mb-3">
<div Class="container">
<a Class="navbar-brand" asp-area="" asp-controller="Home" asp-action="Index">WebApplication1</a>
<button Class="navbar-toggler" type="button" data-toggle="collapse" data-target=".navbar-collapse" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
<span Class="navbar-toggler-icon"></span>
</button>
<div Class="navbar-collapse collapse d-sm-inline-flex flex-sm-row-reverse">
<ul Class="navbar-nav flex-grow-1">
<li Class="nav-item">
<a Class="nav-link text-dark" asp-area="" asp-controller="Home" asp-action="Index">Home</a>
</li>
<li Class="nav-item">
<a Class="nav-link text-dark" asp-area="" asp-controller="Home" asp-action="Privacy">Privacy</a>
</li>
</ul>
</div>
</div>
</nav>
</header>
<div Class="container">
<partial name="_CookieConsentPartial" />
<main role="main" class="pb-3">
<p>
<h3> Browse Students</h3>
<p>Select from 3 students:</p>
<ul>
<li>Adam</li>
<li>Mark</li>
<li>Tom</li>
</ul>
<script>
var x = 5;
document.writeln("students count = 3");
</script>
</p>
</main>
</div>
<footer Class="border-top footer text-muted">
<div Class="container">
copy; 2019 - WebApplication1 - <a asp-area="" asp-controller="Home" asp-action="Privacy">Privacy</a></div>
</footer>
<environment include="Development">
<script src="~/lib/jquery/dist/jquery.js"></script>
<script src="~/lib/bootstrap/dist/js/bootstrap.bundle.js"></script>
</environment>
<environment exclude="Development">
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js" asp-fallback-src="~/lib/jquery/dist/jquery.min.js" asp-fallback-test="window.jQuery" crossorigin="anonymous" integrity="sha256-FgpCb/KJQlLNfOu91ta32o/NMZxltwRo8QtmkMRdAu8="></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.1.3/js/bootstrap.bundle.min.js" asp-fallback-src="~/lib/bootstrap/dist/js/bootstrap.bundle.min.js" asp-fallback-test="window.jQuery, window.jQuery.fn, window.jQuery.fn.modal" crossorigin="anonymous" integrity="sha256-E/V4cWE4qvAeO5MOhjtGtqDzPndRO1LBk8lJ/PR7CA4="></script>
</environment>
<script src="~/js/site.js" asp-append-version="true"></script>
@RenderSection("Scripts", false)
</body>
</html>
This Html code needs further processing to resolve paths, handle asp- attributes, do ant encryption or authentication … etc. All this work is already done in Razor, so I don’t want to reinvent the wheel. I want to know the part of the Razor doing this to deliver my HTML code to and get the work done. I spend days looking at the Razor code but didn’t get what I want, so a little help is appreciated here.
And who are interested, they can participate in the discussion here:
https://github.com/dotnet/vblang/issues/397
Thanks.
2
Answers
I found a perfgect easy solution, by using VirtualPathProvider. But it disapeared in ASP.NET Core! I found an alternative with IFileProvider.. More details here: https://www.mikesdotnetting.com/article/301/loading-asp-net-core-mvc-views-from-a-database-or-other-location but when I tried to register my virual file provider with this code:
I found that FileProviders is no longer a member of RazorViewEngineOptions!
In ASP.NET Core 3.0, it is done using MvcRazorRuntimeCompilationOptions (needs to reference Microsoft.AspNetCore.Mvc.Razor.RuntimeCompilation:
And here is the implementation of this idea: Vazor 1.0 up and running: https://github.com/VBAndCs/Vazor
Vazor is ready now. Start using it today to create wep pages for ASP.NEt Core 3.1 in VB.NET:
1. Install Vazor project templates
2. Install Html5 completion provider VS extension
3. Use the instructions in the ReadMe file
4. Use eShopOnWeb.VB as a guide app.
5. Have fun 🙂
This is the complete story behind Vazor.
And this is a short version published in Visual studio Magazine article.