Yeah, that makes sense indeed.
Thanks!
Markus
-----Original message-----
> From:Chris Hostetter <hossman_luc...@fucit.org>
> Sent: Thursday 15th December 2016 19:44
> To: solr-user@lucene.apache.org
> Subject: RE: DocTransformer not always working
>
>
> : Well, i can work with this really fine knowing this, but does it make
> : sense? I did assume (or be wrong in doing so) that fl=minhash:[binstr]
> : should mean get that field and pass it through the transformer. At least
> : i just now fell for it, maybe other shouldn't :)
>
> that's what it *can* mean, but it's not -- fundementally -- what it means.
>
> foo:[bar x=y ...] means run the "bar" transformer and request that it
> uses the name "foo" as an output key in the resulting documents.
>
> when "bar" is executing it knows what name it was asked to use, so it can
> use that information for other purposes (like in your case: you can use
> that as a stored field name to do some processing on) but there's no
> reason "foo" has to be a real field name.
>
> many processors don't treat the "name" special in any way, and in gneral a
> processor should behave sanely if there is no name specified (ie:
> "fl=[bar]" should be totally valid)
>
> the key reason why it's not really a good idea to *force* the "name" used
> in the response to match a "real" stored field is because it prevents you
> from using multiple transformers on the same field, or from returning the
> same field unmodified.
>
> Another/Better way for you to have designed your transformer would have
> been that the field to apply the binstr logic too should be specified as a
> local param, ie...
>
> fl=minhash,b2_minhash:[binstr f=minhash base=2],b8_minhash:[binstr
> f=minhash base=16]
>
>
> ...see what i mean?
>
>
>
>
> :
> : Anyway, thanks again today,
> : Markus
> :
> : -----Original message-----
> : > From:Chris Hostetter <hossman_luc...@fucit.org>
> : > Sent: Wednesday 14th December 2016 23:14
> : > To: solr-user <solr-user@lucene.apache.org>
> : > Subject: Re: DocTransformer not always working
> : >
> : >
> : > Fairly certain you aren't overridding getExtraRequestFields, so when your
> : > DocTransformer is evaluated it can'd find the field you want it to
> : > transform.
> : >
> : > By default, the ResponseWriters don't provide any fields that aren't
> : > explicitly requested by the user, or specified as "extra" by the
> : > DocTransformer.
> : >
> : > IIUC you want the stored value of the "minhash" field to be available to
> : > you, but the response writer code doesn't know that -- it just knows you
> : > want "minhash" to be the output respons key for the "[binstr]"
> : > transformer.
> : >
> : >
> : > Take a look at RawValueTransformerFactory as an example to borrow from.
> : >
> : >
> : >
> : >
> : > : Date: Wed, 14 Dec 2016 21:55:26 +0000
> : > : From: Markus Jelsma <markus.jel...@openindex.io>
> : > : Reply-To: solr-user@lucene.apache.org
> : > : To: solr-user <solr-user@lucene.apache.org>
> : > : Subject: DocTransformer not always working
> : > :
> : > : Hello - I just spotted an oddity with all two custom DocTransformers we
> sometimes use on Solr 6.3.0. This particular transformer in the example just
> transforms a long (or int) into a sequence of bits. I just use it as an
> convenience to compare minhashes with my eyeballs. First example is very
> straightforward, fl=minhash:[binstr], show only the minhash field, but as a
> bit sequence.
> : > :
> : > :
> solr/search/select?omitHeader=true&wt=json&indent=true&rows=1&sort=id%20asc&q=*:*&fl=minhash:[binstr]
> : > : {
> : > : "response":{"numFound":96933,"start":0,"docs":[
> : > : {}]
> : > : }}
> : > :
> : > : The document is empty! This also happens with another transformer. The
> next example i also request the lang field:
> : > :
> : > : solr/search/select?omitHeader=true&wt=json&indent=true&rows=1&sort=id
> asc&q=*:*&fl=lang,minhash:[binstr]
> : > : {
> : > : "response":{"numFound":96933,"start":0,"docs":[
> : > : {
> : > : "lang":"nl"}]
> : > : }}
> : > :
> : > : Ok, at least i now get the lang field, but the transformed minhash is
> nowhere to be seen. In the next example i request all fields and the
> transformed minhash:
> : > :
> : > :
> /solr/search/select?omitHeader=true&wt=json&indent=true&rows=1&sort=id%20asc&q=*:*&fl=*,minhash:[binstr]
> : > : {
> : > : "response":{"numFound":96933,"start":0,"docs":[
> : > : {
> : > :
> "minhash":"1110110101111010100011010010101111100001110110010111101101111010",
> : > : ...other fields here
> : > : "_version_":1553728923368423424}]
> : > : }}
> : > :
> : > : So it seems that right now, i can only use a transformer properly if i
> request all fields. I believe it used to work with all three examples just as
> you would expect. But since i haven't used transformers for a while, i don't
> know at which version it stopped working like that (if it ever did of course
> :)
> : > :
> : > : Did i mess something up or did a bug creep on me?
> : > :
> : > : Thanks,
> : > : Markus
> : > :
> : >
> : > -Hoss
> : > http://www.lucidworks.com/
> : >
> :
>
> -Hoss
> http://www.lucidworks.com/
>
