RazorEngine - Use Layout and Html.Raw

Question

I'd like to use the following Razor template with RazorEngine:

@{
    Layout = null;
}

@Html.Raw(MyNamespace.MyClass.SomePropertyWithHtml)

When I call it I get 2 errors - one complaining it can't handle Layout, and another complaining it doesn't know how to deal with the Html helper.

There are other questions and answers here suggesting this is possible in v3, and I'm using the current package on NuGet - v3.0.8 - but it isn't clear how this is done. Currently I'm calling it like so:

string html = RazorEngine.Razor.Parse(File.ReadAllText(path));

Other answers suggest using Razor.SetBaseTemplate first, which does not appear in current source or the 3.0 branch on git. Looking at the code I see code referencing layouts and sections, but the layout code appears to depend on resolving a template by name, while what I'm trying to do doesn't even need to resolve a template - I just need it to cope with the Layout = null. The code also includes a MvcTemplateBase that appears to offer an HtmlHelper in the Web project - but it's the sole class in that project and not referenced anywhere in the Web or Core projects.

This similar question: RazorEngine issues with @Html

Just links to the homepage saying you can find out more there - the homepage is just a short sentence describing the project.

So, how do I parse the above Razor view with RazorEngine v3.0?

Answer 1

The Layout property and the Html helper are not a part of TemplateBase, and the implementation of MvcTemplateBase that is a part of the latest version of RazorEngine (v3.4.1) appears incomplete (InitHelpers doesn't seem to initialize the helpers?). You'll need to create your own base template that implements these features.

As you noted, v3+ versions do not include a Razor.SetBaseTemplate method. You can set a base template type in the current version like so:

var config = new RazorEngine.Configuration.TemplateServiceConfiguration
    {
        BaseTemplateType = typeof(MyTemplateBase<>)
    };

using (var service = new RazorEngine.Templating.TemplateService(config))
{
    Razor.SetTemplateService(service);
    return MvcHtmlString.Create(Razor.Parse<TModel>(templateText, model));
}

Should you need to initialize helpers, it may be helpful to override CreateInstance in a custom implementation of IActivator, which can be provided to the TemplateServiceConfiguration like the BaseTemplateType:

var config = new RazorEngine.Configuration.TemplateServiceConfiguration
    {
        BaseTemplateType = typeof(MyTemplateBase<>),
        Activator = new MyActivator()
    };