Ratpack

A micro web framework for Groovy

Ratpack is inspired by the excellent Sinatra framework for Ruby, and aims to make Groovy web development more classy.

Requirements

Groovy 1.7.1+ and Gradle (to build and fetch other dependencies).

Getting Started

Ratpack is still very beta. But, you can start using it right now.

To easily run your app from the command line, copy the jars to your Groovy libs.

gradle deployRatpack

Here's a basic "Hello, World" app:

get("/") {
	"Hello, World!"
}

If you save the above code in hello.groovy and run it on the command line, it will start your app in Jetty on port 5000.

You can also use the 'runapp.groovy' script to auto restart your app when there are changes in the directory.

groovy scripts/runapp.groovy appdir/hello.groovy appdir

POST and Other Verbs

post("/submit") {
    // handle form submission here
}

put("/some-resource") {
    // create the resource
}

delete("/some-resource") {
    // delete the resource
}

register("propfind", "/some-resource") {
    // you can register your own verbs
}

register(["get", "post"], "/formpage") {
    // you can register multiple verbs to the same handler
}

URL Parameters

You can capture parts of the URL to use in your handler code using the colon character. Any parameters that are captured are stored in the urlparams map.

get("/person/:personid") {
    "This is the page for person ${urlparams.personid}"
}

get("/company/:companyname/invoice/:invoiceid") {
    def company = CompanyDAO.getByName(urlparams.companyname)
    def invoice = company.getInvoice(urlparams.invoiceid)
    // you get the idea
}

GET and POST Parameters

Parameters in the query string or passed in via a POST request are available in the params map.

get("/search") {
    def results = SearchEngine.search(params.q)
    // etc.
}

Templates

Render templates using the render method. To specifiy where to load template files from, set the templateRoot setting. If the file isn't found in the template root, the renderer will try to load it as a resource from the classpath.

set 'templateRoot', 'myapp/templates'

get("/") {
    render "homepage.html"
}

You can also pass in a map to use in the template.

get("/page/:pagename") {
    render "page.html", [name: urlparams.pagename]
}

The template syntax is the same as Groovy's SimpleTemplateEngine.

The Development Server

The default port is 5000, but you can specify another if you wish by adding the following to your app:

setPort 8080