Overview
The TemplateEngineFactory manages mappings between file extensions and templating engine builders. It allows registering, overriding, and instantiating engines dynamically — with optional global configuration applied at creation time.
Default instance
A default instance is accessible via:
TemplateEngineFactory.Default
It comes preconfigured with these mappings:
| Extension | Engine |
|---|---|
.liquid |
DotLiquid |
.hbs |
Handlebars |
.st, .stg |
StringTemplate |
.morestachio |
Morestachio |
.mustache |
Morestachio |
.smart |
SmartFormat |
.scriban |
Scriban |
Registering Engines
To support different file types or template syntaxes, you can register template engines by associating them with file extensions. This allows the factory to automatically select the correct engine based on a template’s file extension.
Register a builder directly
factory.AddOrReplace(".foo", new TemplateEngineBuilder().UseScriban());
Register a builder with a lambda
factory.AddOrReplace(".foo", builder => builder.UseScriban());
Creating Engines
To create (instantiate) a configured engine based on file extension:
var engine = factory.Create(".scriban");
If no matching extension is found, a NotSupportedException is thrown.
Global Configuration
You can define a global configuration that will be applied to all engine instances created after it is set.
factory.Configure(config => config.WithHtmlEncode());
This affects any subsequent call to .Create(...):
var engine = factory.Create(".scriban");
// engine.Configuration.HtmlEncode will now return `true` based on configuration
Unlike engine-specific options (like delimiters for StringTemplate), this configuration is shared across all engines and typically affects runtime behavior (e.g., encoding).
Checking and Managing Extensions
To inspect or modify the factory’s registered extensions, a set of utility methods is available. These allow you to check if an extension is supported, list all registered types, or remove or clear mappings as needed.
Check existence
bool exists = factory.Exists(".hbs");
Remove
factory.Remove(".hbs");
Clear all
factory.Clear();
List supported extensions
string[] all = factory.AllSupportedExtensions();
Count total registrations
int count = factory.Count;
Extension Normalization
- All extensions are normalized to start with a dot (
.). "stg"is treated the same as".stg".
Summary
TemplateEngineFactorymaps extensions to template engine builders.Create()builds the appropriate engine, optionally applying a shared configuration.Configure()lets you define a common behavior like HTML encoding across all engines.- Useful for templating systems supporting multiple syntaxes without hardcoding logic.
