Template engine for use in templating scenarios where both the template
source and the expected output are intended to be XML.
Templates may use the normal '${expression}' and '$variable' notations
to insert an arbitrary expression into the template.
In addition, support is also provided for special tags:
<gsp:scriptlet> (for inserting code fragments) and
<gsp:expression> (for code fragments which produce output).
Comments and processing instructions
will be removed as part of processing and special XML characters such as
<, >, " and ' will be escaped using the respective XML notation.
The output will also be indented using standard XML pretty printing.
The xmlns namespace definition for
gsp: tags will be removed
but other namespace definitions will be preserved (but may change to an
equivalent position within the XML tree).
Normally, the template source will be in a file but here is a simple
example providing the XML template as a string:
def binding = [firstname:"Jochen", lastname:"Theodorou",
nickname:"blackdrag", salutation:"Dear"]
def engine = new groovy.text.XmlTemplateEngine()
def text = '''\
<?xml version="1.0" encoding="UTF-8"?>
<document xmlns:gsp='http://groovy.codehaus.org/2005/gsp' xmlns:foo='baz' type='letter'>
<gsp:scriptlet>def greeting = "${salutation}est"</gsp:scriptlet>
<gsp:expression>greeting</gsp:expression>
<foo:to>$firstname "$nickname" $lastname</foo:to>
How are you today?
</document>
'''
def template = engine.createTemplate(text).make(binding)
println template.toString()
This example will produce this output:
<document type='letter'>
Dearest
<foo:to xmlns:foo='baz'>
Jochen "blackdrag" Theodorou
</foo:to>
How are you today?
</document>
The XML template engine can also be used as the engine for
TemplateServlet by placing the
following in your web.xml file (plus a corresponding servlet-mapping element):
<servlet>
<servlet-name>XmlTemplate</servlet-name>
<servlet-class>groovy.servlet.TemplateServlet</servlet-class>
<init-param>
<param-name>template.engine</param-name>
<param-value>groovy.text.XmlTemplateEngine</param-value>
</init-param>
</servlet>