Class ExtendableQueryParser

The ExtendableQueryParser enables arbitrary query parser extension based on a customizable field naming scheme. The lucene query syntax allows implicit and explicit field definitions as query prefix followed by a colon (':') character. The ExtendableQueryParser allows to encode extension keys into the field symbol associated with a registered instance of ParserExtension. A customizable separation character separates the extension key from the actual field symbol. The ExtendableQueryParser splits (SplitExtensionField(String, String)) the extension key from the field symbol and tries to resolve the associated ParserExtension. If the parser can't resolve the key or the field token does not contain a separation character, ExtendableQueryParser yields the same behavior as its super class QueryParser. Otherwise, if the key is associated with a ParserExtension instance, the parser builds an instance of ExtensionQuery to be processed by Parse(ExtensionQuery).If a extension field does not contain a field part the default field for the query will be used.

To guarantee that an extension field is processed with its associated extension, the extension query part must escape any special characters like '*' or '['. If the extension query contains any whitespace characters, the extension query part must be enclosed in quotes. Example ('_' used as separation character):

  title_customExt:"Apache Lucene\?" OR content_customExt:prefix\*

Search on the default field:

  _customExt:"Apache Lucene\?" OR _customExt:prefix\*

The ExtendableQueryParser itself does not implement the logic how field and extension key are separated or ordered. All logic regarding the extension key and field symbol parsing is located in Extensions. Customized extension schemes should be implemented by sub-classing Extensions.

For details about the default encoding scheme see Extensions.

Inheritance
System.Object
QueryParserBase
QueryParser
ExtendableQueryParser
Inherited Members
Namespace: Lucene.Net.QueryParsers.Ext
Assembly: Lucene.Net.QueryParser.dll
Syntax
public class ExtendableQueryParser : QueryParser, ICommonQueryParserConfiguration

Constructors

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ExtendableQueryParser(LuceneVersion, String, Analyzer)

Creates a new ExtendableQueryParser instance

Declaration
public ExtendableQueryParser(LuceneVersion matchVersion, string f, Analyzer a)
Parameters
Type Name Description
LuceneVersion matchVersion

the lucene version to use.
System.String f

the default query field
Analyzer a

the analyzer used to find terms in a query string
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ExtendableQueryParser(LuceneVersion, String, Analyzer, Extensions)

Creates a new ExtendableQueryParser instance

Declaration
public ExtendableQueryParser(LuceneVersion matchVersion, string f, Analyzer a, Extensions ext)
Parameters
Type Name Description
LuceneVersion matchVersion

the lucene version to use.
System.String f

the default query field
Analyzer a

the analyzer used to find terms in a query string
Extensions ext

the query parser extensions

Properties

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ExtensionFieldDelimiter

Returns the extension field delimiter character.

Declaration
public virtual char ExtensionFieldDelimiter { get; }
Property Value
Type Description
System.Char

the extension field delimiter character.

Methods

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GetFieldQuery(String, String, Boolean)

Declaration
protected override Query GetFieldQuery(string field, string queryText, bool quoted)
Parameters
Type Name Description
System.String field
System.String queryText
System.Boolean quoted
Returns
Type Description
Query
Overrides

Implements

See Also