Andy Seaborne wrote:
> On 25/05/12 19:27, Paolo Castagna wrote:
>> Hi Rob
>>
>> Robert Vesse wrote:
>>> There's nothing to stop us making LARQ generate an uber-jar in the same
>>> way we do for Fuseki with maven shade is there?
>>>
>>> This would be sufficient for users if they only had to drop in a single
>>> extra JAR into a directory - most users can manage that ;-)
>>
>> My 0 hasn't flipped to +1, but if you need that feel free to go ahead.
>>
>>> Yes that is my concern that we're making users jump through a lot of
>>> hoops
>>> to extend things
>>
>> Yep.
>>
>>> I thought assemblers can be used to get arbitrary classes loaded so can
>>> you not theoretically have some initializer class for the plugin
>>> (whether
>>> LARQ or otherwise) and add lines to the assembler to get it loaded.
>>>
>>> It seems like assemblers would solve other current problems with LARQ
>>> such
>>> as the ability to specify custom analyzers, index directories etc.
>>> Doing
>>> everything via assembler seems the logical way to go for plugins like
>>> LARQ
>>
>> I am by no means an Assembler expert and perhaps you are right. I hope
>> so.
>>
>> If I remember correctly the problem I had was that in order to build a
>> LARQ
>> index, I needed a Dataset, but I did not find a way to get a reference
>> to an
>> object created by another assembler module from the LARQ ones. I hope I
>> explained this clearly enough.
>>
>> Paolo
>
> +1 to assemblers.
>
> And in general, the "drop jars into a dir" idea works very well with
> assemblers because
>
> [] ja:loadClass "x.y.z.someclass" .
>
> mechanism also invokes a static init() method so the code gets a chance
> to plug into the system during startup.
>
> Paolo - there are various examples of assembler code in the codebase
> e.g. TDB :-)
Hi Andy,
good, thanks for the +1 on assemblers.
The thing that I struggled with is how to get a reference to a Dataset (built by
an assembler in TDB or other systems, SDB) when I need to build an IndexLARQ.
I need a reference to a Dataset since I want to register a listener to be
notified as new triples|quads are added/removed (and update Lucene index
accordingly).
Dataset dataset = ... ;
IndexBuilderModel larqBuilder = new IndexBuilderString(indexWriter) ;
dataset.getDefaultModel().register(larqBuilder);
for ( Iterator<String> iter = dataset.listNames() ; iter.hasNext() ; ) {
String g = iter.next() ;
dataset.getNamedModel(g).register(larqBuilder) ;
}
This was the reasons of the 'pollution' and call to make(...) via reflection in
ARQ's DatasetAssembler.
Is there an example of an assembler which uses and/or get a reference to an
object build elsewhere via another assembler?
This is what I am not sure is possible and if it is possible, I do not know how
to do it with assemblers.
A similar requirement would arise if we want to have an assembler which build a
Dataset wrapping an existing assembler object built by another assembler from
TDB or SDB.
(I hope I explained my problem clearly enough... I have not tried yet to do this
again, from scratch and avoiding any change to ARQ or TDB code as it should be
to allow third party to plug-in their extensions transparently).
Paolo
>
> Andy
