Jade is a high performance template engine heavily influenced by Haml. The rjade package interfaces to the JavaScript library using V8, the embedded JavaScript engine for R. Below an example of a Jade template, taken from the jade homepage. This example template includes one variable called youAreUsingJade.
doctype html
html(lang="en")
head
title= pageTitle
script(type='text/javascript').
if (foo) {
bar(1 + 5)
}
body
h1 Jade - node template engine
#container.col
if youAreUsingJade
p You are amazing
else
p Get on it!
p.
Jade is a terse and simple
templating language with a
strong focus on performance
and powerful features.Converting a template to HTML text involves two steps. The first step compiles the template with some formatting options into a closure. The binding for this is implemented in jade_compile.
# Compile a Jade template in R
text <- readLines(system.file("examples/test.jade", package = "rjade"))
tpl <- jade_compile(text, pretty = TRUE)The second step calls the closure with optionally some local variables to render the output to HTML.
# Render the template
tpl()<!DOCTYPE html>
<html lang="en">
<head>
<title></title>
<script type="text/javascript">
if (foo) {
bar(1 + 5)
}
</script>
</head>
<body>
<h1>Jade - node template engine</h1>
<div id="container" class="col">
<p>Get on it!</p>
<p>
Jade is a terse and simple
templating language with a
strong focus on performance
and powerful features.
</p>
</div>
</body>
</html> Note how the HTML output changes when setting local variables:
tpl(youAreUsingJade = TRUE)<!DOCTYPE html>
<html lang="en">
<head>
<title></title>
<script type="text/javascript">
if (foo) {
bar(1 + 5)
}
</script>
</head>
<body>
<h1>Jade - node template engine</h1>
<div id="container" class="col">
<p>You are amazing</p>
<p>
Jade is a terse and simple
templating language with a
strong focus on performance
and powerful features.
</p>
</div>
</body>
</html>