Package groovy.text

Class XmlTemplateEngine

  • public class XmlTemplateEngine
extends TemplateEngine
    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 &quot;blackdrag&quot; 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>