package at.gv.egovernment.moa.id.auth.builder;

import at.gv.egovernment.moa.id.BuildException;

/**
 * Base class for HTML/XML builders providing commonly useful functions.
 * 
 * @author Paul Ivancsics
 * @version $Id$
 */
public class Builder {
  
  /**
   * Replaces a special tag in an XML or HTML template by a value.
   * @param htmlTemplate template
   * @param tag special tag
   * @param value value replacing the tag
   * @return XML or HTML code, the tag replaced
   * @throws BuildException when template does not contain the tag
   */
  protected String replaceTag(String template, String tag, String value) throws BuildException {
    int index = template.indexOf(tag);
    if (index < 0)
      throw new BuildException(
        "builder.01", 
        new Object[] {"&lt;" + tag.substring(1, tag.length() - 1) + "&gt;"});
    return template.substring(0, index) + value + template.substring(index + tag.length());
  }

}