Mark Mandel wrote his own version of Coldfusion’s XmlTransform() function, using the underlying Java transform classes. Although one of his annoyances—that XmlTransform() won’t take any parameters—has been solved in CFMX7, XmlTransform() is nonetheless a slow operation, as the transform engine has to be cranked up, the XSL compiled, the transform effected and then everything garbage-collected, each call to the function, each request.
To improve Coldfusion for dedicated XSL programmers, I’ve turned Mark’s one-off function into a more granular component for cacheable, Java-based XSL transformations, called CFJavaXML. You can cache this component from request to request in a persisting scope. You can also compile an XSL transformation once, then store that in a persisting scope too and re-use it without having to keep accessing the XSL file (and compiling it, which can take time). It’ll bring in all its xsl:import references at compilation too, so you needn’t worry about having to keep track of your XSL directory from transformation to transformation.
The component needs no initialization, so create it as follows:
<cfset comp_cfjx = createObject(”component”, “#PATH_TO_COMPONENTS#.cfjavaxml”)>
You can cache this in a persisting scope at this point.
Using CFJavaXML is always a two-stage process, so that you get a compiled transformation object you can store and re-use. In the following example, XSL and XML can be either local file://(/) references, http:// URLs or even strings of valid XML:
<script>
t = comp_cfjx.XslTextToTransformer( XSL );
xmltext = comp_cfjx.XmlTransformFromTextAndJava( XML, t [, params]);
<script>
(The transform t is the compiled transform that you can cache from request to request.) Note also where any optional parameters can be inserted, using a params struct.
Depending on the transformation (and how many times you use it) the speed increase of using CFJavaXML has been quite striking: up to ten times with certain transformations. Benchmarking is quite difficult because it depends so much on the intricacy of the XSL: your mileage may vary.
(Thanks to my employers, Torchbox, who’ve given me permission to make this code available, and thanks to Mark for showing how to do it in the first place!)
