KinoSearch::Docs::TutoUser:ContribuKinoSearch::Docs::Tutorial::BeyondSimple(3)NAMEKinoSearch::Docs::Tutorial::BeyondSimple - A more flexible app
structure.
DESCRIPTION
Goal
In this tutorial chapter, we'll refactor the apps we built in
KinoSearch::Docs::Tutorial::Simple so that they look exactly the same
from the end user's point of view, but offer the developer greater
possibilites for expansion.
To achieve this, we'll ditch KSx::Simple and replace it with the
classes that it uses internally:
· KinoSearch::Plan::Schema - Plan out your index.
· KinoSearch::Plan::FullTextType - Field type for full text search.
· KinoSearch::Analysis::PolyAnalyzer - A one-size-fits-all
parser/tokenizer.
· KinoSearch::Index::Indexer - Manipulate index content.
· KinoSearch::Search::IndexSearcher - Search an index.
· KinoSearch::Search::Hits - Iterate over hits returned by a
Searcher.
Adaptations to indexer.pl
After we load our modules...
use KinoSearch::Plan::Schema;
use KinoSearch::Plan::FullTextType;
use KinoSearch::Analysis::PolyAnalyzer;
use KinoSearch::Index::Indexer;
... the first item we're going need is a Schema.
The primary job of a Schema is to specify what fields are available and
how they're defined. We'll start off with three fields: title, content
and url.
# Create Schema.
my $schema = KinoSearch::Plan::Schema->new;
my $polyanalyzer = KinoSearch::Analysis::PolyAnalyzer->new(
language => 'en',
);
my $type = KinoSearch::Plan::FullTextType->new(
analyzer => $polyanalyzer,
);
$schema->spec_field( name => 'title', type => $type );
$schema->spec_field( name => 'content', type => $type );
$schema->spec_field( name => 'url', type => $type );
All of the fields are spec'd out using the "FullTextType" FieldType,
indicating that they will be searchable as "full text" -- which means
that they can be searched for individual words. The "analyzer", which
is unique to FullTextType fields, is what breaks up the text into
searchable tokens.
Next, we'll swap our KSx::Simple object out for a
KinoSearch::Index::Indexer. The substitution will be straightforward
because Simple has merely been serving as a thin wrapper around an
inner Indexer, and we'll just be peeling away the wrapper.
First, replace the constructor:
# Create Indexer.
my $indexer = KinoSearch::Index::Indexer->new(
index => $path_to_index,
schema => $schema,
create => 1,
truncate => 1,
);
Next, have the $indexer object "add_doc" where we were having the
$simple object "add_doc" before:
foreach my $filename (@filenames) {
my $doc = slurp_and_parse_file($filename);
$indexer->add_doc($doc);
}
There's only one extra step required: at the end of the app, you must
call commit() explicitly to close the indexing session and commit your
changes. (KSx::Simple hides this detail, calling commit() implicitly
when it needs to).
$indexer->commit;
Adaptations to search.cgi
In our search app as in our indexing app, KSx::Simple has served as a
thin wrapper -- this time around KinoSearch::Search::IndexSearcher and
KinoSearch::Search::Hits. Swapping out Simple for these two classes is
also straightforward:
use KinoSearch::Search::IndexSearcher;
my $searcher = KinoSearch::Search::IndexSearcher->new(
index => $path_to_index,
);
my $hits = $searcher->hits( # returns a Hits object, not a hit count
query => $q,
offset => $offset,
num_wanted => $hits_per_page,
);
my $hit_count = $hits->total_hits; # get the hit count here
...
while ( my $hit = $hits->next ) {
...
}
Hooray!
Congratulations! Your apps do the same thing as before... but now
they'll be easier to customize.
In our next chapter, KinoSearch::Docs::Tutorial::FieldType, we'll
explore how to assign different behaviors to different fields.
COPYRIGHT AND LICENSE
Copyright 2005-2010 Marvin Humphrey
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
perl v5.14.12KinoSearch::Docs::Tutorial::BeyondSimple(3)
