asp.net-mvcasp.net-mvc-3razor
I have a textarea control that accepts input. I am trying to later render that text to a view by simply using:
@Model.CommentText
This is properly encoding any values. However, I want to replace the line break characters with <br /> and I can't find a way to make sure that the new br tags don't get encoded. I have tried using HtmlString but haven't had any luck yet.
Here's what I came up with, and it's working for me. I added the following method(s) to my controller base class. (You can always make these static methods somewhere else that accept a controller as a parameter I suppose)
MVC2 .ascx style
protected string RenderViewToString<T>(string viewPath, T model) {
ViewData.Model = model;
using (var writer = new StringWriter()) {
var view = new WebFormView(ControllerContext, viewPath);
var vdd = new ViewDataDictionary<T>(model);
var viewCxt = new ViewContext(ControllerContext, view, vdd,
new TempDataDictionary(), writer);
viewCxt.View.Render(viewCxt, writer);
return writer.ToString();
}
}
Razor .cshtml style
public string RenderRazorViewToString(string viewName, object model)
{
ViewData.Model = model;
using (var sw = new StringWriter())
{
var viewResult = ViewEngines.Engines.FindPartialView(ControllerContext,
viewName);
var viewContext = new ViewContext(ControllerContext, viewResult.View,
ViewData, TempData, sw);
viewResult.View.Render(viewContext, sw);
viewResult.ViewEngine.ReleaseView(ControllerContext, viewResult.View);
return sw.GetStringBuilder().ToString();
}
}
Edit: added Razor code.
Since a comprehensive list does not appear to exist, let's start one here on SO. This can be of great value to the ASP.NET MVC community if people add their experience (esp. anyone who contributed to one of these). Anything implementing IViewEngine (e.g. VirtualPathProviderViewEngine) is fair game here. Just alphabetize new View Engines (leaving WebFormViewEngine and Razor at the top), and try to be objective in comparisons.
System.Web.Mvc.WebFormViewEngine
Design Goals:
A view engine that is used to render a Web Forms page to the response.
Pros:
Cons:
Example:
<%@ Control Inherits="System.Web.Mvc.ViewPage<IEnumerable<Product>>" %>
<% if(model.Any()) { %>
<ul>
<% foreach(var p in model){%>
<li><%=p.Name%></li>
<%}%>
</ul>
<%}else{%>
<p>No products available</p>
<%}%>
Design Goals:
Pros:
Cons:
Con Example #1 (notice the placement of "string[]..."):
@{
<h3>Team Members</h3> string[] teamMembers = {"Matt", "Joanne", "Robert"};
foreach (var person in teamMembers)
{
<p>@person</p>
}
}
Design goals:
- Respect HTML as first-class language as opposed to treating it as "just text".
- Don't mess with my HTML! The data binding code (Bellevue code) should be separate from HTML.
- Enforce strict Model-View separation
Design Goals:
The Brail view engine has been ported from MonoRail to work with the Microsoft ASP.NET MVC Framework. For an introduction to Brail, see the documentation on the Castle project website.
Pros:
Cons:
Example:
<html>
<head>
<title>${title}</title>
</head>
<body>
<p>The following items are in the list:</p>
<ul><%for element in list: output "<li>${element}</li>"%></ul>
<p>I hope that you would like Brail</p>
</body>
</html>
Hasic uses VB.NET's XML literals instead of strings like most other view engines.
Pros:
Cons:
Example:
Protected Overrides Function Body() As XElement
Return _
<body>
<h1>Hello, World</h1>
</body>
End Function
Design Goals:
NDjango is an implementation of the Django Template Language on the .NET platform, using the F# language.
Pros:
WebFormViewEngineDesign Goals:
.NET port of Rails Haml view engine. From the Haml website:
Haml is a markup language that's used to cleanly and simply describe the XHTML of any web document, without the use of inline code... Haml avoids the need for explicitly coding XHTML into the template, because it is actually an abstract description of the XHTML, with some code to generate dynamic content.
Pros:
Cons:
Example:
@type=IEnumerable<Product>
- if(model.Any())
%ul
- foreach (var p in model)
%li= p.Name
- else
%p No products available
NVelocityViewEngine (MvcContrib)
Design Goals:
A view engine based upon NVelocity which is a .NET port of the popular Java project Velocity.
Pros:
Cons:
Example:
#foreach ($p in $viewdata.Model)
#beforeall
<ul>
#each
<li>$p.Name</li>
#afterall
</ul>
#nodata
<p>No products available</p>
#end
Design Goals:
SharpTiles is a partial port of JSTL combined with concept behind the Tiles framework (as of Mile stone 1).
Pros:
Cons:
Example:
<c:if test="${not fn:empty(Page.Tiles)}">
<p class="note">
<fmt:message key="page.tilesSupport"/>
</p>
</c:if>
Design Goals:
The idea is to allow the html to dominate the flow and the code to fit seamlessly.
Pros:
Cons:
Example:
<viewdata products="IEnumerable[[Product]]"/>
<ul if="products.Any()">
<li each="var p in products">${p.Name}</li>
</ul>
<else>
<p>No products available</p>
</else>
<Form style="background-color:olive;">
<Label For="username" />
<TextBox For="username" />
<ValidationMessage For="username" Message="Please type a valid username." />
</Form>
StringTemplate View Engine MVC
Design Goals:
- Lightweight. No page classes are created.
- Fast. Templates are written to the Response Output stream.
- Cached. Templates are cached, but utilize a FileSystemWatcher to detect file changes.
- Dynamic. Templates can be generated on the fly in code.
- Flexible. Templates can be nested to any level.
- In line with MVC principles. Promotes separation of UI and Business Logic. All data is created ahead of time, and passed down to the template.
Pros:
Cons:
Wing Beats is an internal DSL for creating XHTML. It is based on F# and includes an ASP.NET MVC view engine, but can also be used solely for its capability of creating XHTML.
Pros:
Cons:
Design Goals:
Builds views from familiar XSLT
Pros:
Cons:
Best Answer
Use the CSS white-space property instead of opening yourself up to XSS vulnerabilities!