Grzegorz Kossakowski skrev:
Hello,

I'm still working on refactoring Forms and Ajax. Following Daniel's
advice[1] I try to configure LinkRewriterTransformer for needs of
rewriting servlet: links to the resources. I need use ChainMetaModule,
because it has concatation feature (<all-values> configuration option).
Sadly, I've encountered its quirk, take a look at getAttribute method:
    public Object getAttribute( String attr, Configuration modeConf, Map
objectModel )
    throws ConfigurationException {
        Object[] values =
this.getAttributeValues(attr,modeConf,objectModel);
        if (getLogger().isDebugEnabled()) getLogger().debug("result
chaining single for "+attr+" is "+(values != null? values[0] : "null"));
        return (values != null? values[0] : null);
    }

In order to get one value it scans through all modules listing all
possible values! Not only this is inefficient but also narrows possible
usage. Block-path module obviously does not support listing all values
because list would be endless. Given this, ChainMetaModule is useless in
this case.

I would like to ask few questions:
1. Does anyone know why ChainMetaModule behaves the way described above?

No idea.

2. Would you be happy if I rewritten it from scratch with
back-compatibility in mind?

Yes.

3. If so, would be happy if I used Java 1.5 features?

No, Cocoon 2.2 is supposed to work with Java 1.4. We had a vote about it some while ago.

Or do you have better options?

Maybe it would be a better idea to write a special purpose link rewriter for the block protocol. Where you only configure what attributes to rewrite. Looking at the code for the link rewriting transformer, the actual work is just a few rows. Most of it is about handling all the bewildering amount of configuration options.

/Daniel

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