Template basics

Getting Started

Please read the Quick intro first!

RazorEngine provides a base implementation of a template class, the TemplateBase, this is normally superseded by the model specific template class, the TemplateBase<T>. For most use cases, we're hoping this will be enough. To get started with template using RazorEngine, you can simply use the static Engine type (the Engine.Razor instance):

string template = "<div>Hello @Model.Name</div>";
var model = new Person { Name = "Matt" };

string result = Engine.Razor.RunCompile(template, "key", typeof(Person), model);

Which should result in:

<div>Hello Matt</div>

The type always needs to be given explicitly, this way you can decide if you want to use a base class or dynamic (null) instead of model.GetType().

Using Anonymous Types

RazorEngine supports anonymous types (those declared as var with no identifier, e.g. var model = { Name = "Matt" };. The set of statements to use an anonymous model, is exactly the same as a statically type model (as seen above):

string template = "<div>Hello @Model.Name</div>";
var model = new { Name = "Matt" };

string result = Engine.Razor.RunCompile(template, "key", null, model);

Because the generated anonymous type is internal so RazorEngine needs to use some tricks to make this work. This is also the reason you can't use model.GetType() in this situation. RazorEngine will wrap your instance of the anonymous class in a wrapper. This wrapper ensures that we can access everything, even across AppDomains (IsolatedRazorEngineService).

Note: You can use this wrapper class yourself with var model = new RazorDynamicObject(myInternalModel). This wrapper will make sure everything works. You can even use this if you have a model that is NOT serializable which you want to use in an isolated sandbox. However this will slighly hit performance.

Using Dynamic Types

RazorEngine has support for dynamic types (those declared as dynamic). Again, the structure for using dynamic types is very similar. All you need to do is to use null for the modelType parameter (so the same template will be generated as for anonymous types).

string template = "<div>Hello @Model.Name</div>";
dynamic model = new ExpandoObject();
model.Name = "Matt";

string result = Engine.Razor.RunCompile(template, "key", null, (object)model);

Note: You can run into problems when not casting the model to object.

Supported syntax.

You can access several things when you use the default TemplateBase<> implementation:

  • @using Custom.Namespace (see also the quick intro and assembly resolvers for custom references)

  • @model ModelType

  • @inherits HtmlSupportTemplateBase<ModelType> (see below)

  • Set a layout (and @RenderBody() within the layout template):

        Layout = "layout.cshtml";
  • @Include("templateName", model = null, modelType = null) to include another template.

  • Accessing the ViewBag:

  • Sections (@DefineSection, @RenderSection and @IsSectionDefined)

Extending the template Syntax.

As explained in the "About Razor" section the template gets compiled into a method. This method is part of a class that implements ITemplate. You are free to provide your own base-class implementations however we recommend to inherit from TemplateBase<T> if you need special syntax.

One common feature request is to provide the @Html.Raw() (or any other not-Razor specific) syntax, but it is very easy to run that on your own:

public class MyHtmlHelper
    public IEncodedString Raw(string rawString)
        return new RawString(rawString);

public abstract class HtmlSupportTemplateBase<T> : TemplateBase<T>
    public MyClassImplementingTemplateBase()
        Html = new MyHtmlHelper();

    public MyHtmlHelper Html { get; set; }

And then you can use it like:

var config = new TemplateServiceConfiguration();
// You can use the @inherits directive instead (this is the fallback if no @inherits is found).
config.BaseTemplateType = typeof(HtmlSupportTemplateBase<>);
using (var service = RazorEngineService.Create(config))
    string template = "@Html.Raw(Model.Data)";
    var model = new { Data = "My raw double quotes appears here \"hello!\"" };

    string result = service.RunCompile(template, "htmlRawTemplate", null, model);
    Console.WriteLine("Template: {0}", template);
    Console.WriteLine("Result: {0}", result);

Resolving and Caching Templates

The process of getting the source code of a template from a name (or ITemplateKey rather) is called resolving a template. This is delegated to the ITemplateManager implementation.

A ITemplateKey uniquely describes a template, however multiple ITemplateKey instances can point to the same template.

For example if a ITemplateManager implementation doesn't make a difference between the given ResolveType.

To prevent multiple compilations for such templates the ITemplateKey interface has the GetUniqueKeyString method which returns a unique string to be used by the caching layer for caching. Keep this in mind when implementing the ITemplateManager interface and therefore creating ITemplateKey instances.

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