package org.trails.component;

 import java.util.List;

 import java.util.Locale;

 import ognl.Ognl;

 import ognl.OgnlException;

 import org.apache.tapestry.BaseComponent;

 import org.apache.tapestry.annotations.InjectObject;

 import org.apache.tapestry.annotations.Parameter;

 import org.apache.tapestry.components.Block;

 import org.trails.TrailsRuntimeException;

 import org.trails.descriptor.IClassDescriptor;

 import org.trails.descriptor.IPropertyDescriptor;

 import org.trails.i18n.ResourceBundleMessageSource;

 public abstract class ClassDescriptorComponent extends BaseComponent

 {

         public ClassDescriptorComponent()

         {

                 super();

                 // TODO Auto-generated constructor stub

         }

         @Parameter(required = false, defaultValue = "page.classDescriptor", cache = true)

         public abstract IClassDescriptor getClassDescriptor();

         public abstract void setClassDescriptor(IClassDescriptor ClassDescriptor);

         @Parameter(required = false, defaultValue = "ognl:null", cache = true)

         public abstract String[] getPropertyNames();

         public abstract void setPropertyNames(String[] PropertyNames);

         /**

          * @return

          * @throws OgnlException

          */

         public List<IPropertyDescriptor> getPropertyDescriptors()

         {

                 if (getPropertyNames() == null || getPropertyNames().length == 0)

                 {

                         try

                         {

                                 return (List) Ognl.getValue("#this.{? not(hidden)}", getClassDescriptor().getPropertyDescriptors());

                         }

                         catch (OgnlException oe)

                         {

                                 throw new TrailsRuntimeException(oe, getClassDescriptor().getType());

                         }

                 } else

                 {

                         return getClassDescriptor().getPropertyDescriptors(getPropertyNames());

                 }

         }

         /**

          * Return the Spring ResourceBundleMessageSource. This is used to implement

          * i18n in all Trails components, accessing a i18n properties file in the

          * application instead of accessing the property file located in org.trais.component package.

          * By doing this, someone who would need i18n wouldn't need to change the property

          * located in the org.trails.component package and rebuild the trails.jar

          *

          * @return

          */

         @InjectObject("spring:trailsMessageSource")

         public abstract ResourceBundleMessageSource getResourceBundleMessageSource();

         public String getMessage(String key)

         {

                 Locale locale = getContainer().getPage().getEngine().getLocale();

                 return getResourceBundleMessageSource().getMessageWithDefaultValue(key, locale, "[TRAILS][" + key.toUpperCase() + "]");

         }

         public boolean hasBlock(String propertyName)

         {

                 if (getPage().getComponents().containsKey(propertyName))

                 {

                         return true;

                 }

                 return false;

         }

         public Block getBlock(String propertyName)

         {

                 if (getPage().getComponents().containsKey(propertyName))

                 {

                         return (Block) getPage().getComponent(propertyName);

                 }

                 return null;

         }

 }