Package org.elasticsearch.index.mapper

Class SourceValueFetcher

org.elasticsearch.index.mapper.SourceValueFetcher

All Implemented Interfaces:

ValueFetcher

public abstract class SourceValueFetcher
extends 
implements ValueFetcher

An implementation of ValueFetcher that knows how to extract values from the document source. Most standard field mappers will use this class to implement value fetching.

Field types that handle arrays directly should instead use ArraySourceValueFetcher.

Constructor Summary

Constructors

Constructor	Description
fieldName, SearchExecutionContext context)
fieldName, SearchExecutionContext context, nullValue)
<> sourcePaths, nullValue)

Method Summary

Modifier and Type	Method	Description
<>	fetchValues(SourceLookup lookup)	Given access to a document's _source, return this field's values.
static SourceValueFetcher	fieldName, SearchExecutionContext context, format)	Creates a SourceValueFetcher that passes through source values unmodified.
protected abstract	value)	Given a value that has been extracted from a document's source, parse it into a standard format.
static SourceValueFetcher	fieldName, SearchExecutionContext context, format)	Creates a SourceValueFetcher that converts source values to strings.
static SourceValueFetcher	<> sourcePaths)	Creates a SourceValueFetcher that converts source values to Strings

Methods inherited from class java.lang.

, , , , , , , , , ,

Methods inherited from interface org.elasticsearch.index.mapper.ValueFetcher

setNextReader

Constructor Details

SourceValueFetcher

public SourceValueFetcher( fieldName,
 SearchExecutionContext context)

SourceValueFetcher

public SourceValueFetcher( fieldName,
 SearchExecutionContext context,
  nullValue)

Parameters:

fieldName - The name of the field.

context - The query shard context

nullValue - An optional substitute value if the _source value is 'null'.

SourceValueFetcher

public SourceValueFetcher(<> sourcePaths,
  nullValue)

Parameters:

sourcePaths - The paths to pull source values from

nullValue - An optional substitute value if the _source value is `null`

Method Details

fetchValues

public <> fetchValues(SourceLookup lookup)

Description copied from interface: ValueFetcher

Given access to a document's _source, return this field's values. In addition to pulling out the values, they will be parsed into a standard form. For example numeric field mappers make sure to parse the source value into a number of the right type. Note that for array values, the order in which values are returned is undefined and should not be relied on.

Specified by:

fetchValues in interface ValueFetcher

Parameters:

lookup - a lookup structure over the document's source.

Returns:

a list a standardized field values.

parseSourceValue

protected abstract  parseSourceValue( value)

Given a value that has been extracted from a document's source, parse it into a standard format. This parsing logic should closely mirror the value parsing in FieldMapper.parseCreateField(org.elasticsearch.index.mapper.ParseContext) or FieldMapper.parse(org.elasticsearch.index.mapper.ParseContext).

identity

public static  fieldName,
 SearchExecutionContext context,
  format)

Creates a SourceValueFetcher that passes through source values unmodified.

toString

public static  fieldName,
 SearchExecutionContext context,
  format)

Creates a SourceValueFetcher that converts source values to strings.

toString

public static <> sourcePaths)

Creates a SourceValueFetcher that converts source values to Strings

Parameters:

sourcePaths - the paths to fetch values from in the source