All Downloads are FREE. Search and download functionalities are using the official Maven repository.
  • Log In
  • Register

    • com.espertech.esper.view.std.FirstElementViewFactory Maven / Gradle / Ivy

    There is a newer version: 7.1.0
    Show newest version
    /**************************************************************************************
 * Copyright (C) 2006-2015 EsperTech Inc. All rights reserved.                        *
 * http://www.espertech.com/esper                                                          *
 * 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.view.std;

import com.espertech.esper.client.EventType;
import com.espertech.esper.core.context.util.AgentInstanceViewFactoryChainContext;
import com.espertech.esper.core.service.StatementContext;
import com.espertech.esper.epl.expression.core.ExprNode;
import com.espertech.esper.view.*;

import java.util.List;

/**
 * Factory for {@link com.espertech.esper.view.std.FirstElementView} instances.
 */
public class FirstElementViewFactory implements AsymetricDataWindowViewFactory
{
    public final static String NAME = "First-Event";

    private EventType eventType;

    public void setViewParameters(ViewFactoryContext viewFactoryContext, List expressionParameters) throws ViewParameterException
    {
        List viewParameters = ViewFactorySupport.validateAndEvaluate(getViewName(), viewFactoryContext.getStatementContext(), expressionParameters);
        if (!viewParameters.isEmpty())
        {
            String errorMessage = getViewName() + " view does not take any parameters";
            throw new ViewParameterException(errorMessage);
        }
    }

    public void attach(EventType parentEventType, StatementContext statementContext, ViewFactory optionalParentFactory, List parentViewFactories) throws ViewParameterException
    {
        this.eventType = parentEventType;
    }

    public View makeView(AgentInstanceViewFactoryChainContext agentInstanceViewFactoryContext)
    {
        return new FirstElementView(this);
    }

    public EventType getEventType()
    {
        return eventType;
    }

    public boolean canReuse(View view)
    {
        if (!(view instanceof FirstElementView))
        {
            return false;
        }
        return true;
    }

    public String getViewName() {
        return NAME;
    }
}
    
    
    
    

    




    
    
    © 2015 - 2025 Weber Informatics LLC | Privacy Policy