org.apache.slide.search.basic
Class BasicExpressionCompiler

java.lang.Object
  org.apache.slide.search.basic.BasicExpressionCompiler

All Implemented Interfaces:

IBasicExpressionCompiler

public class BasicExpressionCompiler

extends java.lang.Object

implements IBasicExpressionCompiler

The implementation of the IBasicExpressionCompiler interface.

Version:

$Revision: 1.10 $

Field Summary

protected boolean	alreadyTriedToInstantiate Inidicates if it has already been tried to instantiate the storeSpecificExpressionFactory.
protected IBasicExpressionFactory	contentExpressionFactory The store specific IBasicExpressionFactory for content expressions to use (if one exists).
protected IBasicExpressionFactory	genericExpressionFactory The default IBasicExpressionFactory to use.
protected IBasicExpressionFactory	propertiesExpressionFactory The store specific IBasicExpressionFactory for property expressions to use (if one exists).
protected PropertyProvider	propertyProvider The PropertyProvider to use (if set).
protected IBasicQuery	query The IBasicQuery that provides some general information about the query.

Constructor Summary

BasicExpressionCompiler(IBasicQuery query, PropertyProvider propertyProvider)
Creates the BasicExpressionCompiler, loads and inits the expression factories.

Method Summary

IBasicExpression	compile(org.jdom.Element expressionElement) Compiles an IBasicExpression (-tree) from the given expressionElement.
static boolean	isContentExpression(org.jdom.Element expressionElement) Checks, if an expression is a contains expression.
static boolean	isMergeExpression(org.jdom.Element expressionElement) Returns true if the given expressionElement describes a merge expression.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

query

protected IBasicQuery query

The IBasicQuery that provides some general information about the query.

propertyProvider

protected PropertyProvider propertyProvider

The PropertyProvider to use (if set).

genericExpressionFactory

protected IBasicExpressionFactory genericExpressionFactory

The default IBasicExpressionFactory to use.

propertiesExpressionFactory

protected IBasicExpressionFactory propertiesExpressionFactory

The store specific IBasicExpressionFactory for property expressions to use (if one exists).

contentExpressionFactory

protected IBasicExpressionFactory contentExpressionFactory

The store specific IBasicExpressionFactory for content expressions to use (if one exists).

alreadyTriedToInstantiate

protected boolean alreadyTriedToInstantiate

Inidicates if it has already been tried to instantiate the storeSpecificExpressionFactory.

Constructor Detail

BasicExpressionCompiler

public BasicExpressionCompiler(IBasicQuery query,
                               PropertyProvider propertyProvider)
                        throws BadQueryException

Creates the BasicExpressionCompiler, loads and inits the expression factories. If no store / indexer specific factory is defined, the generic expression factory is used.

Parameters:

query - the IBasicQuery.

propertyProvider - the PropertyProvider to use (may be null).

Method Detail

compile

public IBasicExpression compile(org.jdom.Element expressionElement)
                         throws BadQueryException

Compiles an IBasicExpression (-tree) from the given expressionElement.

Specified by:

compile in interface IBasicExpressionCompiler

Parameters:

expressionElement - the (root) expression Element to compile into an IBasicExpression.

Returns:

the compiled IBasicExpression.

Throws:

BadQueryException - if compiling the expression failed.

isMergeExpression

public static boolean isMergeExpression(org.jdom.Element expressionElement)

Returns true if the given expressionElement describes a merge expression.

Parameters:

expressionElement - the Element that describes the expression.

Returns:

true if the given expressionElement describes a merge expression.

isContentExpression

public static boolean isContentExpression(org.jdom.Element expressionElement)

Checks, if an expression is a contains expression. TODO: ask the contentIndexer, if it knows this expression (to allow proprietary extensions to DASL, for example , )

Parameters:

expressionElement - an Element

Returns:

a boolean