Ferret talk - Aug 2006 - Ferret 0.10 and Fields

Hey ...

I just tried to convert my code to 0.10 .. But i''m currently not sure
how to use fields..

i really like some of the new api.. its leaner and i like the fact that
these strange consts are gone (like
Ferret::Search::BooleanClause::Occur::MUST) ..

I see that you''re now having Ferret::Index::FieldInfo to describe the
fields of the index.. thats good.. and i now see that documents and
fields are much smaller and easier to create.. thats good as well :-)

now what i dont get is how to add a field to a document.. i can create a
new field or a document, but how to make give the field a name? i would
expect something like

doc = Document.new
fiels = Field.new("my data to be indexed", 1.5)
doc.add_field( ''title'', field ) 

or

doc.title = field ..

can''t see anything like that in the API though..

Ben

On Wed, Aug 23, 2006 at 08:22:42PM +0200, Benjamin Krause
wrote:
> Hey ...
> 
> I just tried to convert my code to 0.10 .. But i''m currently not
sure
> how to use fields..
> 
> i really like some of the new api.. its leaner and i like the fact that
> these strange consts are gone (like
> Ferret::Search::BooleanClause::Occur::MUST) ..
> 
> I see that you''re now having Ferret::Index::FieldInfo to describe
the
> fields of the index.. thats good.. and i now see that documents and
> fields are much smaller and easier to create.. thats good as well :-)
> 
> now what i dont get is how to add a field to a document.. i can create a
> new field or a document, but how to make give the field a name? i would
> expect something like
> 
> doc = Document.new
> fiels = Field.new("my data to be indexed", 1.5)
> doc.add_field( ''title'', field ) 
> 
> or
> 
> doc.title = field ..
> 
> can''t see anything like that in the API though..
it''s as easy as doc[:title] = field

Jens

-- 
webit! Gesellschaft f?r neue Medien mbH          www.webit.de
Dipl.-Wirtschaftsingenieur Jens Kr?mer       kraemer at webit.de
Schnorrstra?e 76                         Tel +49 351 46766  0
D-01069 Dresden                          Fax +49 351 46766 66

On 8/24/06, Jens Kraemer <kraemer at webit.de>
wrote:
> On Wed, Aug 23, 2006 at 08:22:42PM +0200, Benjamin Krause wrote:
> > Hey ...
> >
> > I just tried to convert my code to 0.10 .. But i''m currently
not sure
> > how to use fields..
> >
> > i really like some of the new api.. its leaner and i like the fact
that
> > these strange consts are gone (like
> > Ferret::Search::BooleanClause::Occur::MUST) ..
> >
> > I see that you''re now having Ferret::Index::FieldInfo to
describe the
> > fields of the index.. thats good.. and i now see that documents and
> > fields are much smaller and easier to create.. thats good as well :-)
> >
> > now what i dont get is how to add a field to a document.. i can create
a
> > new field or a document, but how to make give the field a name? i
would
> > expect something like
> >
> > doc = Document.new
> > fiels = Field.new("my data to be indexed", 1.5)
> > doc.add_field( ''title'', field )
> >
> > or
> >
> > doc.title = field ..
> >
> > can''t see anything like that in the API though..
>
> it''s as easy as doc[:title] = field
>
> Jens
Just to clarify. Hashes are the new Documents. If you don''t use the
boost field then use a Hash. It''s much simpler. Everyone knows how to
use a Hash.

    index << {:title => "Shawshank Redemption", :tags =>
["Drama",
"Suspense", "Jail", "Prison"]}

In fact if you don''t want to use the Document class at all;

    class Hash
        include BoostMixin
    end

    doc = {:title => "Shawshank Redemption", :tags =>
["Drama",
"Suspense", "Jail", "Prison"]}

    doc.boost = 100.0

NOTE: all fields should now be Symbols. Strings will work in most
cases but Symbols are what is expected. They''re much more efficient
anyway.

I mean to do a big write up explaining the changes but I just don''t
have the time right now. Perhaps tomorrow.

Cheers,
Dave

hey..
>> it''s as easy as doc[:title] = field
thats quite easy.. indeed :)
> NOTE: all fields should now be Symbols. Strings will work in most
> cases but Symbols are what is expected. They''re much more
efficient
> anyway.
what if i add a field to a doc that was not initialized using fieldinfos?
will this be added anyway and just fallback to the default fieldinfos?
is there a way to prevent fields from beeing added if there is no
fieldinfo definition? And if not, will there be a way?

Thanks,
Ben

On 8/24/06, Benjamin Krause <bk at benjaminkrause.com>
wrote:
> hey..
>
> >> it''s as easy as doc[:title] = field
>
> thats quite easy.. indeed :)
>
> > NOTE: all fields should now be Symbols. Strings will work in most
> > cases but Symbols are what is expected. They''re much more
efficient
> > anyway.
>
> what if i add a field to a doc that was not initialized using fieldinfos?
> will this be added anyway and just fallback to the default fieldinfos?
> is there a way to prevent fields from beeing added if there is no
> fieldinfo definition? And if not, will there be a way?
>
> Thanks,
> Ben
Great question. Another thing I should elloborate on. When you create
the FieldInfos object you can set the default fields for any unknown
fields you add later. For example

    fi = FieldInfos.new(:store => :no, :term_vector => :no)

    # fields are normally stored by default but now we''ve set the
default :store
    # value to :no so we need to explicitly state that we want to store fields;
    fi.add_fields(:title, :store => :yes, :index => :untokenized)

    index = Index.new(:field_infos => fi)
    index << {:title => "asdg", :content =>
"asdlkgjhasdkgjh"}

Cheers,
Dave