optionstag.java

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package ar.com.koalas.providers.taglibs.struts;

import java.util.Collection;
import java.util.Iterator;

import javax.servlet.jsp.JspException;

import org.apache.commons.collections.CollectionUtils;
import org.apache.commons.collections.Predicate;

import ar.com.koalas.providers.Provider;
import ar.com.koalas.providers.ProviderFactory;
import ar.com.koalas.providers.taglibs.comboselect.ComboSelectTag;
import ar.com.koalas.providers.taglibs.comboselect.SelectData;

/**
 * Genera los Options necesarios para un combo Select
 * @author gmeyer
 */
public class OptionsTag extends org.apache.struts.taglib.html.OptionsTag {
	private String provider=null;
	private Provider providerImpl = null;
	
	private class OptionsPredicate implements Predicate {
		public boolean evaluate(Object arg) {
			Object context = OptionsTag.this.pageContext.getRequest();
			return OptionsTag.this.providerImpl.evaluateFilter( arg, context );
		}
	}
	 
	protected Iterator getIterator(String arg0, String arg1)
		throws JspException {
		
		
		if(this.getProvider()==null)
			return super.getIterator(arg0, arg1);
			
		try {
			ProviderFactory factory = ProviderFactory.getInstance();
			this.providerImpl = factory.getProvider(this.pageContext, this.getProvider());
			this.property = this.providerImpl.getKeyName();
			this.labelProperty = this.providerImpl.getDescription();
			Collection filteredCollection = CollectionUtils.select( this.providerImpl.getCollection(), new OptionsPredicate() );
			return filteredCollection.iterator();
		} catch (Exception e) {
			e.printStackTrace();
			throw new JspException("Error en el provider " + this.getProvider() + ". : " + e.getMessage());
		}			
	}
	
	/**
	 * @return
	 */
	public String getProvider() {
		return provider;
	}

	/**
	 * @param string
	 */
	public void setProvider(String string) {
		provider = string;
		//for options tag to work properly
		this.collection=string;
	}

	public void release() {
		super.release();
		this.provider=null;
		this.providerImpl=null;
	}
	
	public int doEndTag() throws JspException {
		//si esta anidado en un comboselect, le notifica el contenido y skipea 
		SelectTag st = (SelectTag)findAncestorWithClass(this, SelectTag.class);
		ComboSelectTag cst = (ComboSelectTag)findAncestorWithClass(this, ComboSelectTag.class);
		if(cst!=null && st!=null) {
			Iterator it = null;
	        if (this.collection != null) {
	        	it = getIterator(this.collection, null);
	        } else {
	        	it = getIterator(this.name, this.property);
	        }
			cst.putSelectData(st.getProperty(), new SelectData(it, this.property, this.labelProperty));
			return EVAL_PAGE;
		}

		return super.doEndTag();
	}
}