Carsten Ziegeler schrieb:
Bertrand Delacretaz wrote:
On Wed, Jul 16, 2008 at 5:14 AM, Sylvain Wallez <[EMAIL PROTECTED]>
wrote:
...Can't we just give the parameters they need
individually to every pipeline component, thus allowing per-component
strongly typed and well defined contracts?..
I'm also catching up on this thread but I tend to agree with the above
suggestion, i.e. something like
Transformer t = new XsltTransformer();
t.setXslt("cocoon:/mytransform.xsl");
t.setRequestParameters(request.getParameterMap());
...
Ok, in this case you can't use "Transformer" as the class type. This
would be:
XsltTransformer t = ...
Now, it seems that we are still mixing up things here. As I said, I'm
not talking about configuration of the components. The stylesheet from
above is a configuration.
We're talking about information about the current environment for
executing the already configured pipeline.
IIUC the request parameters in the above example would belong to the
execution environment, wouldn't they?
I'd imagine something like this:
public void parameterizeTransformers(Request req, Pipeline pipeline) {
for (Iterator i = pipeline.getTransformers().iterator(); … ) {
Transformer t = (Transformer) i.next();
if (t instanceof WebappXsltTransformer) {
WebappXsltTransformer xsltTr = (WebappXsltTransformer) t;
if (xsltTr.useRequestParameters()) {
xsltTr.setXsltParams(req.getParameterMap());
}
}
}
}
IMO passing the execution environment to a pipeline component depends
very much on the nature of the environment, and also on the nature of
the individual components. I'm not sure if it should be attempted to
find a generic API for this. Wouldn't it be sufficient to let the client
code handle this? I guess this is what Torsten and Jörg had in mind when
they suggested a callback mechanism:
public class ServletPipelineInvoker {
protected Pipeline createPipeline() {
Pipeline pipeline = new NonCachingPipeline();
pipeline.addListener(this);
return pipeline;
}
/**
* Called before pipeline execution.
* @see PipelineListener.contextualizePipeline(Pipeline)
*/
public void contextualizePipeline(Pipeline pipeline) {
parameterizeTransformers(this.request, pipeline);
}
}
-- Andreas
--
Andreas Hartmann, CTO
BeCompany GmbH
http://www.becompany.ch
Tel.: +41 (0) 43 818 57 01
