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Lucy::Docs::Tutorial::FieldTypeTutorial – Apache Lucy Documentation
Apache Lucy™

NAME

Lucy::Docs::Tutorial::FieldTypeTutorial - Specify per-field properties and behaviors.

DESCRIPTION

The Schema we used in the last chapter specifies three fields:

my $type = Lucy::Plan::FullTextType->new(
    analyzer => $easyanalyzer,
);
$schema->spec_field( name => 'title',   type => $type );
$schema->spec_field( name => 'content', type => $type );
$schema->spec_field( name => 'url',     type => $type );

Since they are all defined as “full text” fields, they are all searchable – including the url field, a dubious choice. Some URLs contain meaningful information, but these don’t, really:

http://example.com/us_constitution/amend1.txt

We may as well not bother indexing the URL content. To achieve that we need to assign the url field to a different FieldType.

StringType

Instead of FullTextType, we’ll use a StringType, which doesn’t use an Analyzer to break up text into individual fields. Furthermore, we’ll mark this StringType as unindexed, so that its content won’t be searchable at all.

my $url_type = Lucy::Plan::StringType->new( indexed => 0 );
$schema->spec_field( name => 'url', type => $url_type );

To observe the change in behavior, try searching for us_constitution both before and after changing the Schema and re-indexing.

Toggling ‘stored’

For a taste of other FieldType possibilities, try turning off stored for one or more fields.

my $content_type = Lucy::Plan::FullTextType->new(
    analyzer => $easyanalyzer,
    stored   => 0,
);

Turning off stored for either title or url mangles our results page, but since we’re not displaying content, turning it off for content has no effect – except on index size.

Analyzers up next

Analyzers play a crucial role in the behavior of FullTextType fields. In our next tutorial chapter, AnalysisTutorial, we’ll see how changing up the Analyzer changes search results.