IParameterResolver.java

/*
 * This program is free software; you can redistribute it and/or modify it under the 
 * terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software 
 * Foundation.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this 
 * program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html 
 * or from the Free Software Foundation, Inc., 
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * This program 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.
 *
 * Copyright 2006 - 2008 Pentaho Corporation.  All rights reserved.
 */
package org.pentaho.platform.api.engine;

import java.util.regex.Matcher;

public interface IParameterResolver {

  /**
   * Provides a way for components to inject their own replacements of parameter markers in the
   * provided template. This currently exposes too much of the internals of TemplateUtil IMO, but
   * without serious surgery on the TemplateUtil, this is about the only way to accomplish the task.
   * 
   * @param template The string containing replacement parameters
   * @param parameterName The name of the located parameter in the template
   * @param parameterMatcher The Regex matcher that located the parameter
   * @param copyStart The current start to copy from the template
   * @param result The final string with the parameter replacements inlined
   * @return integer indicating the new copyStart to be used in the TemplateUtil in the
   * event that the component handled the parameter. If negative, then no processing was
   * done in the component. Any value greater than or equal to zero indicates processing
   * happened in the component.
   * 
   * TODO: Change this interface to make it easier to do things without exposing the internals
   * of TemplateUtil. 
   */
  public int resolveParameter(String template, String parameterName, Matcher parameterMatcher, int copyStart,
      StringBuffer result);

}