Hel in writing my own transformer.

[Angelo Immediata <an...@libero.it>]

Hi all. I need to implement a my own transform that does a link rewriter. the scope is to change the href value of <a tag in a html file (a well formed html file checked by jtidy as you can check in the file jtidy.xml). I have realize for now the code:

package it.transformers;

import org.apache.cocoon.transformation.AbstractSAXTransformer;
import org.xml.sax.Attributes;
import java.io.IOException;
import java.util.Map;
import org.apache.cocoon.ProcessingException;
import org.apache.cocoon.portal.transformation.CopletTransformer;
import org.apache.avalon.framework.parameters.Parameters;
import org.xml.sax.SAXException;
import org.apache.cocoon.environment.SourceResolver;
import org.apache.cocoon.xml.AttributesImpl;
import java.util.Stack;

public class HTMLLinkTransformer extends AbstractSAXTransformer {

    protected Stack elementStack = new Stack();

    public void recycle() {
        super.recycle();
        this.elementStack.clear();
    }

    public void setup(SourceResolver resolver,
                      Map objectModel,
                      String src,
                      Parameters par)
    throws ProcessingException, SAXException, IOException {
        super.setup(resolver, objectModel, src, par);

    }

    public void startElement(String uri, String name, String raw, Attributes attr)
    throws SAXException {
        if ("a".equalsIgnoreCase(name) || "xhtml:a".equalsIgnoreCase( name ) ) {

            AttributesImpl newAttr = new AttributesImpl();
            newAttr.setValue(attr.getIndex("href"),"ciao");
            attr = newAttr;
        }
        super.startElement( uri, name, raw,attr );
    }

    public void endElement(String uri, String name, String raw) throws SAXException {
        super.endElement(uri, name, raw);
    }
}

By using it i have this error:
ERROR   (2005-10-26) 23:35.13:739   [sitemap.handled-errors] (/pmm/portal/coplets/S062/execute.service) http-8080-Processor8/ErrorHandlerHelper: Error executing pipeline.
org.apache.cocoon.ProcessingException: Error executing pipeline.: org.w3c.dom.DOMException: HIERARCHY_REQUEST_ERR: An attempt was made to insert a node where it is not permitted. 
	at org.apache.cocoon.components.pipeline.AbstractProcessingPipeline.handleException(AbstractProcessingPipeline.java:940)
	at org.apache.cocoon.components.pipeline.impl.AbstractCachingProcessingPipeline.processXMLPipeline(AbstractCachingProcessingPipeline.java:281)
	at org.apache.cocoon.components.pipeline.AbstractProcessingPipeline.process(AbstractProcessingPipeline.java:783)
	at org.apache.cocoon.components.source.impl.SitemapSource.toSAX(SitemapSource.java:413)
	at org.apache.cocoon.components.source.SourceUtil.toSAX(SourceUtil.java:142)
	at org.apache.cocoon.components.source.SourceUtil.toSAX(SourceUtil.java:100)
	at org.apache.cocoon.components.source.SourceUtil.toDOM(SourceUtil.java:332)
	at org.apache.cocoon.components.flow.util.PipelineUtil.processToDOM(PipelineUtil.java:173)


Can anybody help me? Thanks to all.