org.simpleframework.xml.core.TemplateFilter Maven / Gradle / Ivy
/*
* TemplateFilter.java May 2005
*
* Copyright (C) 2005, Niall Gallagher
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General
* Public License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307 USA
*/
package org.simpleframework.xml.core;
import org.simpleframework.xml.filter.Filter;
/**
* The TemplateFilter class is used to provide variables
* to the template engine. This template acquires variables from two
* different sources. Firstly this will consult the user contextual
* Context object, which can contain variables that have
* been added during the deserialization process. If a variable is
* not present from this context it asks the Filter that
* has been specified by the user.
*
* @author Niall Gallagher
*/
class TemplateFilter implements Filter {
/**
* This is the template context object used by the persister.
*/
private Context context;
/**
* This is the filter object provided to the persister.
*/
private Filter filter;
/**
* Constructor for the TemplateFilter object. This
* creates a filter object that acquires template values from
* two different contexts. Firstly the Context is
* queried for a variables followed by the Filter.
*
* @param context this is the context object for the persister
* @param filter the filter that has been given to the persister
*/
public TemplateFilter(Context context, Filter filter) {
this.context = context;
this.filter = filter;
}
/**
* This will acquire the named variable value if it exists. If
* the named variable cannot be found in either the context or
* the user specified filter then this returns null.
*
* @param name this is the name of the variable to acquire
*
* @return this returns the value mapped to the variable name
*/
public String replace(String name) {
Object value = context.getAttribute(name);
if(value != null) {
return value.toString();
}
return filter.replace(name);
}
}