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.
Implements
Inherited Members
Namespace: Lucene.Net.QueryParsers.Ext
Assembly: Lucene.Net.QueryParser.dll
Syntax
public class ExtendableQueryParser : QueryParser, ICommonQueryParserConfigurationConstructors
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. |
| string | f | the default query field |
| Analyzer | a | the analyzer used to find terms in a query string |
See Also
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. |
| string | f | the default query field |
| Analyzer | a | the analyzer used to find terms in a query string |
| Extensions | ext | the query parser extensions |
See Also
Properties
ExtensionFieldDelimiter
Returns the extension field delimiter character.
Declaration
public virtual char ExtensionFieldDelimiter { get; }Property Value
| Type | Description |
|---|---|
| char | the extension field delimiter character. |
See Also
Methods
GetFieldQuery(string, string, bool)
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.
Declaration
protected override Query GetFieldQuery(string field, string queryText, bool quoted)Parameters
| Type | Name | Description |
|---|---|---|
| string | field | |
| string | queryText | |
| bool | quoted |
Returns
| Type | Description |
|---|---|
| Query |
Overrides
Exceptions
| Type | Condition |
|---|---|
| ParseException | throw in overridden method to disallow |