Class | Ferret::Index::FieldInfos
In: | lib/ferret/field_infos.rb ext/r_index.c
Parent: | Object

## Summary

The FieldInfos class holds all the field descriptors for an index. It is this class that is used to create a new index using the FieldInfos#create_index method. If you are happy with the default properties for FieldInfo then you don‘t need to worry about this class. IndexWriter can create the index for you. Otherwise you should set up the index like in the example;

## Example

      field_infos = FieldInfos.new(:term_vector => :no)

      field_infos.add_field(:title, :index => :untokenized, :term_vector => :no,
                            :boost => 10.0)

      field_infos.add_field(:content)

      field_infos.add_field(:created_on, :index => :untokenized_omit_norms,
                            :term_vector => :no)

      field_infos.add_field(:image, :store => :compressed, :index => :no,
                            :term_vector => :no)

      field_infos.create_index("/path/to/index")

## Default Properties

See FieldInfo for the available field property values.

When you create the FieldInfos object you specify the default properties for the fields. Often you‘ll specify all of the fields in the index before you create the index so the default values won‘t come into play. However, it is possible to continue to dynamically add fields as indexing goes along. If you add a document to the index which has fields that the index doesn‘t know about then the default properties are used for the new field.

### Methods

<< [] add add_field create_index each fields load new size to_a to_s tokenized_fields

### Public Class methods

load(yaml_str)

Load FieldInfos from a YAML file. The YAML file should look something like this: default:

      store: :yes
      index: :yes
      term_vector: :no

fields:

      id:
        index: :untokenized
        term_vector: :no

      title:
        boost: 20.0
        term_vector: :no

      content:
        term_vector: :with_positions_offsets

FieldInfos.new(defaults = {}) → field_infos

Create a new FieldInfos object which uses the default values for fields specified in the `default` hash parameter. See FieldInfo for available property values.

### Public Instance methods

fis << fi → fis
fis.add(fi) → fis

Add a FieldInfo object. Use the FieldInfos#add_field method where possible.

fis[name] → field_info
fis[number] → field_info

Get the FieldInfo object. FieldInfo objects can be referenced by either their field-number of the field-name (which must be a symbol). For example;

      fi = fis[:name]
      fi = fis[2]

fis << fi → fis
fis.add(fi) → fis

Add a FieldInfo object. Use the FieldInfos#add_field method where possible.

fis.add_field(name, properties = {} → fis

Add a new field to the FieldInfos object. See FieldInfo for a description of the available properties.

fis.create_index(dir) → self

Create a new index in the directory specified. The directory `dir` can either be a string path representing a directory on the file-system or an actual directory object. Care should be taken when using this method. Any existing index (or other files for that matter) will be deleted from the directory and overwritten by the new index.

fis.each {|fi| do_something } → fis

Iterate through the FieldInfo objects.

fis.fields → symbol array

Return a list of the field names (as symbols) of all the fields in the index.

fis.size → int

Return the number of fields in the FieldInfos object.

fis.to_a → array

Return an array of the FieldInfo objects contained but this FieldInfos object.

fis.to_s → string

Return a string representation of the FieldInfos object.

fis.tokenized_fields → symbol array

Return a list of the field names (as symbols) of all the tokenized fields in the index.

[Validate]