Mustache

Ktor allows you to use Mustache templates as views within your application by installing the Mustache plugin (previously known as feature).

Add dependencies

To enable Mustache support, you need to include the ktor-mustache artifact in the build script:

implementation "io.ktor:ktor-mustache:$ktor_version"

implementation("io.ktor:ktor-mustache:$ktor_version")

        
                    <dependency>
                        <groupId>io.ktor</groupId>
                        <artifactId>ktor-mustache</artifactId>
                        <version>${ktor_version}</version>
                    </dependency>
                    
        

Install Mustache

To install the Mustache plugin, pass it to the install function in the application initialization code. Depending on the way used to create a server, this can be the embeddedServer function call ...

            import io.ktor.features.*
            // ...
            fun main() {
                embeddedServer(Netty, port = 8080) {
                    install(Mustache)
                    // ...
                }.start(wait = true)
            }
        

... or a specified module.

            import io.ktor.features.*
            // ...
            fun Application.module() {
                install(Mustache)
                // ...
            }
        

Inside the install block, you can configure the MustacheFactory for loading Mustache templates.

Configure Mustache

Configure template loading

To load templates, you need to assign the MustacheFactory to the mustacheFactory property. For example, the code snippet below enables Ktor to look up templates in the templates package relative to the current classpath:

    install(Mustache) {
        mustacheFactory = DefaultMustacheFactory("templates")
    }

Send a template in response

Imagine you have the index.hbs template in resources/templates:

<html>
    <body>
        <h1>Hello, {{user.name}}</h1>
    </body>
</html>

A data model for a user looks as follows:

data class User(val id: Int, val name: String)

To use the template for the specified route, pass MustacheContent to the call.respond method in the following way:

get("/index") {
    val sampleUser = User(1, "John")
    call.respond(MustacheContent("index.hbs", mapOf("user" to sampleUser)))
}

Last modified: 28 May 2021