Hello,
I’m working on a project where it would be most helpful for
getWrappedAnalyzer() in an extension to DelegatingAnalyzerWrapper to have
access to more than just the fieldName.
The scenario is that we are working with several languages: Tibetan, Sanskrit
and Chinese; that each have several encodings, e.g., Simplified Chinese
(zh-hans), Traditional Chinese (zh-hant), Pinyin with diacritics (zh-pinyin)
and Pinyin without diacritics (zh-pinyin-ndia). Our data is from many sources
which each use a variety of encodings and we wish to preserve the original
encodings used in the data.
For Chinese, for example, we have an analyzer that creates a TokenStream of
Pinyin with diacritics for any of the input encodings. Thus it is possible in
some situations to retrieve documents originally input as zh-hans and so on.
The same applies to the other languages.
One objective is to allow the user to input a query in zh-pinyin, for example,
and to retrieve documents that were originally indexed in any of the variant
encodings.
The current scheme, in Apache Jena + Lucene, is to create a fieldName that
includes the original name plus a language tag, e.g., label_zh-hans, so that
the getWrappedAnalyzer() can then retrieve a registered analyzer for zh-hans
that will then index using Pinyin tokens as mentioned above.
For Chinese, we end up with documents that have four different fields:
label_zh-hans, label_zh-hant, label_zh-pinyin, and label_zh-pinyin-ndia, so
that when indexing we know what input encoding was used so that an appropriate
analyzer configuration can be chosen since the analyzer has to be aware of the
incoming encoding.
At search time we could try a search like:
(label_zh-hans:a-query-in-pinyin OR label_zh-hant:a-query-in-pinyin OR
label_zh-pinyin:a-query-in-pinyin OR label_zh-pinyin-ndia:a-query-in-pinyin)
But this can not work since the information that the query is in zh-pinyin is
not available to the getWrappedAnalyzer(), only the original encoding is
available as a part of the field name and so it is not possible to know that
the query string is in zh-pinyin so that is tokenized correctly when querying
the other fields.
I’m probably over-thinking things, but it seems to me that if I had a way of
accessing additional context when choosing an analyzer so that there would be
information that the query string is in pinyin and the various field names are
available as usual.
I don’t see how a custom query analyzer would help here. We would know that the
context of the call to the analyzer wrapper was for query versus indexing but
we still don’t know the field name versus the encoding of the query.
I imagine this sort of scenario has been solved by others numerous times but
I’m stumped as to how to implement.
Thanks in advance for any help,
Chris
