/**************************************************************************************
* Copyright (C) 2008 EsperTech, Inc. All rights reserved. *
* http://esper.codehaus.org *
* http://www.espertech.com *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the GPL license *
* a copy of which has been included with this distribution in the license.txt file. *
**************************************************************************************/
package com.espertech.esper.client.soda;
import java.io.Serializable;
import java.io.StringWriter;
import java.util.List;
/**
* Filter defines the event type to be filtered for, and an optional expression that returns true if
* the filter should consider the event, or false to reject the event.
*/
public class Filter implements Serializable
{
private static final long serialVersionUID = 0L;
private String eventTypeName;
private Expression filter;
private List<ContainedEventSelect> optionalPropertySelects;
/**
* Ctor.
*/
public Filter() {
}
/**
* Creates a filter to the given named event type.
* @param eventTypeName is the event type name to filter for
* @return filter
*/
public static Filter create(String eventTypeName)
{
return new Filter(eventTypeName);
}
/**
* Creates a filter to the given named event type and filter expression.
* @param eventTypeName is the event type name to filter for
* @param filter is the expression filtering out events
* @return filter is the filter expression
*/
public static Filter create(String eventTypeName, Expression filter)
{
return new Filter(eventTypeName, filter);
}
/**
* Ctor.
* @param eventTypeName is the event type name
*/
public Filter(String eventTypeName)
{
this.eventTypeName = eventTypeName;
}
/**
* Ctor.
* @param eventTypeName is the event type name
* @param filter is the filter expression
*/
public Filter(String eventTypeName, Expression filter)
{
this.eventTypeName = eventTypeName;
this.filter = filter;
}
/**
* Returns the name of the event type to filter for.
* @return event type name
*/
public String getEventTypeName()
{
return eventTypeName;
}
/**
* Sets the name of the event type to filter for.
* @param eventTypeName name of the event type to filter for
*/
public void setEventTypeName(String eventTypeName)
{
this.eventTypeName = eventTypeName;
}
/**
* Returns the optional filter expression that tests the event, or null if no filter expression was defined.
* @return filter expression
*/
public Expression getFilter()
{
return filter;
}
/**
* Sets the optional filter expression that tests the event, or null if no filter expression is needed.
* @param filter is the filter expression to set
*/
public void setFilter(Expression filter)
{
this.filter = filter;
}
/**
* Returns contained-event spec.
* @return spec
*/
public List<ContainedEventSelect> getOptionalPropertySelects()
{
return optionalPropertySelects;
}
/**
* Sets the contained-event selection, if any.
* @param optionalPropertySelects spec
*/
public void setOptionalPropertySelects(List<ContainedEventSelect> optionalPropertySelects)
{
this.optionalPropertySelects = optionalPropertySelects;
}
/**
* Returns a textual representation of the filter.
* @param writer to output to
* @param formatter for newline-whitespace formatting
*/
public void toEPL(StringWriter writer, EPStatementFormatter formatter)
{
writer.write(eventTypeName);
if (filter != null)
{
writer.write('(');
filter.toEPL(writer, ExpressionPrecedenceEnum.MINIMUM);
writer.write(')');
}
if (optionalPropertySelects != null)
{
for (ContainedEventSelect propertySelect : optionalPropertySelects)
{
writer.write('[');
propertySelect.toEPL(writer, formatter);
writer.write(']');
}
}
}
}