package org.apache.struts.tiles.xmlDefinition;
import org.apache.struts.tiles.ComponentDefinition;
import org.apache.struts.tiles.NoSuchDefinitionException;
import java.util.Iterator;
/**
*A definition red from an XML definitions file.
*/
public class XmlDefinition extends ComponentDefinition
{
/**
* Extends attribute value.
*/
private String inherit;
/** Debug flag */
static public final boolean debug = false;
/**
* Use for resolving inheritance.
*/
private boolean isVisited=false;
/**
* Constructor.
*/
public XmlDefinition()
{
super();
//if(debug)
//System.out.println( "create definition" );
}
/**
* add an attribute to this component
*
* @param attribute Attribute to add.
*/
public void addAttribute( XmlAttribute attribute)
{
putAttribute( attribute.getName(), attribute.getValue() );
}
/**
* Sets the value of the extend and path property.
*
* @param aPath the new value of the path property
*/
public void setExtends(String name)
{
inherit = name;
}
/**
* Access method for the path property.
*
* @return the current value of the path property
*/
public String getExtends()
{
return inherit;
}
/**
* Get the value of the extendproperty.
*
*/
public boolean isExtending( )
{
return inherit!=null;
}
/**
* Get the value of the extendproperty.
*
*/
public void setIsVisited( boolean isVisited )
{
this.isVisited = isVisited;
}
/**
* Resolve inheritance.
* First, resolve parent's inheritance, then set path to the parent's path.
* Also copy attributes setted in parent, and not set in child
* If instance doesn't extends something, do nothing.
* @throw NoSuchInstanceException If a inheritance can be solved.
*/
public void resolveInheritance( XmlDefinitionsSet definitionsSet )
throws NoSuchDefinitionException
{
// Already done, or not needed ?
if( isVisited || !isExtending() )
return;
if( debug)
System.out.println( "Resolve definition for child name='"
+ getName() + "' extends='"
+ getExtends() + "'." );
// Set as visited to avoid endless recurisvity.
setIsVisited( true );
// Resolve parent before itself.
XmlDefinition parent = definitionsSet.getDefinition( getExtends() );
if( parent == null )
{ // error
String msg = "Error while resolving definition inheritance: child '"
+ getName() + "' can't find its ancestor '"
+ getExtends() + "'. Please check your description file.";
System.out.println( msg );
// to do : find better exception
throw new NoSuchDefinitionException( msg );
}
parent.resolveInheritance( definitionsSet );
// Iterate on each parent's attribute, and add it if not defined in child.
Iterator parentAttributes = parent.getAttributes().keySet().iterator();
while( parentAttributes.hasNext() )
{
String name = (String)parentAttributes.next();
if( !getAttributes().containsKey(name) )
putAttribute( name, parent.getAttribute(name) );
}
// Set path and role if not setted
if( path == null )
setPath( parent.getPath() );
if( role == null )
setRole( parent.getRole() );
}
/**
* Overload this definition with passed child.
* All attributes from child are copied to this definition. Previous attribute with
* same name are disguarded.
* Special attribute 'path','role' and 'extends' are overloaded if defined in child.
* @param child Child used to overload this definition.
*/
public void overload( XmlDefinition child )
{
if( child.getPath() != null )
{
path = child.getPath();
}
if( child.getExtends() != null )
{
inherit = child.getExtends();
}
if( child.getRole() != null )
{
role = child.getRole();
}
// put all child attributes in parent.
attributes.putAll( child.getAttributes());
}
}