The Mozilla Rhino engine for the JavaScript programming language is currently included as a feature in the JDK/JRE 6 and 7 libraries.
<transform>
<script engine="JavaScript">
main();
function main()
{
target.put('F01',source.get('F02'));
target.put('F02',source.get('F01'));
return target;
}
</script>
</transform>This example uses JavaScript to swap fields F01 and F02, any other fields are auto-mapped. The source and target variables are implemented as java.util.Map<String,String> objects where the key is the field name and the value is the data value. TransformIO updates these variables for each record. A third map common, not used in this example, can be used to pass named object values across records.
Note: The data value is always a String, as parsed, from the source record. Type conversion is left to transform script which can better convert the value to numbers, dates, etc. It is best to do casting in the transform where exceptions can be handled with the power of the scripting language! For this reason, TransformIO does not provide type specification in the source or target records where field values are just strings.
To use Java as a scripting engine, download the JAR from Patrodyne Scripting for Java, put it in TransformIO's lib/engine directory and restart TransformIO.
<transform>
<script engine="JavaCode">
<![CDATA[
import java.util.*;
import javax.script.*;
class Main
{
private static ScriptContext ctx;
public static void setScriptContext(ScriptContext ctx) { Main.ctx = ctx; }
public static void main(String[] args)
{
Map<String,Object> common = (Map<String,Object>) ctx.getAttribute("common");
Map<String,String> source = (Map<String,String>) ctx.getAttribute("source");
Map<String,String> target = (Map<String,String>) ctx.getAttribute("target");
target.put("F01",source.get("F02"));
target.put("F02",source.get("F01"));
}
}
]]>
</script>
</transform>This example uses Java to swap two fields and auto-map any other fields; otherwise, it is similar to the JavaScript example.
For Java, the ScriptContext requires a setter to get the context variables from TransformIO. Because the main method cannot return a value, TransformIO retrieves the target object from the context after each transformation.
Note: This example wraps the script in <![CDATA[...]]> because the code includes characters that must be hidden from XML.
To use Jython as a scripting engine, download the JAR from one of the following links, put it in TransformIO's lib/engine directory and restart TransformIO.
<transform>
<script engine="jython">
class Main:
def run(self):
main();
target.put('F01',source.get('F02'));
target.put('F02',source.get('F01'));
Main().run()
</script>
</transform>This example uses Jython to swap two fields and auto-map any other fields; otherwise, it is similar to the JavaScript example.
Because the main method does not return a value, TransformIO retrieves the target object from the context after each transformation.
To use Groovy as a scripting engine, download the JAR from one of the following links, put it in TransformIO's lib/engine directory and restart TransformIO.
<transform>
<script engine="groovy">
target.put('F01',source.get('F02'));
target.put('F02',source.get('F01'));
return target;
</script>
</transform>This example uses Groovy to swap two fields and auto-map any other fields; otherwise, it is similar to the JavaScript example.
Note: 'return target;' is optional.
To use BeanShell as a scripting engine, download the JAR from one of the following links, put it in TransformIO's lib/engine directory and restart TransformIO.
<transform>
<script engine="beanshell">
target.put("F01",source.get("F02"));
target.put("F02",source.get("F01"));
return target;
</script>
</transform>This example uses BeanShell to swap two fields and auto-map any other fields; otherwise, it is similar to the JavaScript example.
Note: 'return target;' is optional.