Re: A question about filters

[Johann Petrak <johann petrak chello at>]

Alex Mac wrote:
> On 28/04/07, Johann Petrak <johann petrak chello at> wrote:
>> Is it possible to have multiple filters for a a group of files
>> where each provides their own part of (meta)information about
>> the files?
>> For example, a user might have a collection of documents
>> (e.g. PDF, plain text, OpenOffice) but there is also an
>> application that stores meta information like authors,
>> project, dates, internal numbers etc. that is associated
>> with these documents.
>> So ... would it be possible for the existing PDF, OpenOffice,
>> Text etc. filters to provide the conventional information
>> (e.g. the content) and for and *additional* filter to
>> access the database and provide that additional information?
>>
>> How would a use then be able to query for files using those
>> additional properties?
>>
>> I am considering using beeagle as the back-end for some
>> inhouse dekstop search solution that would utilize
>> additional information about files (not only documents)
>> so something like this would be essential ...
> 
> soon beagle will support XMP sidecar files which will be able to
> contain arbitrary metadata. So if you have a file "thing.foo" you
> would create a file called "thing.foo.xmp" which contained whatever
> properties you wanted.
> 
> It's still in development but hopefully it will be included in the next
> release
> 
I am happy to hear that but it does not really answer my question.
In my case that feature would not help really, because all the
arbitrary metadata is in a database and creating and keeping up-to-date
a seperate .xmp file for each file we have metadata for would be total
overkill and unnecessary complex.

So what I wanted to know is whether I could just plug-in a filter that
would for any file beagle crawl/indexes *add* the metadata we have
in the database -- and how I would have to do that. And also, how
users would then be able to search for that metadata.

In general (and probably important for more than just this application)
is it possible to combine several filters so that each can contribute
a subset of the metainformation that is being indexed by beagle for
some URI?

Thank you for your help!

Cheers,
  Johann