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Lucy::Docs::Tutorial::FieldType(3pm) User Contributed Perl Documentation Lucy::Docs::Tutorial::FieldType(3pm)

NAME

Lucy::Docs::Tutorial::FieldType - 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 => $polyanalyzer,
    );
    $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 => $polyanalyzer,
        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, Lucy::Docs::Tutorial::Analysis, we'll see how changing up the Analyzer changes search results.

2017-08-02 perl v5.26.0