package net.sourceforge.phpdt.externaltools.variable;

/**********************************************************************
 Copyright (c) 2002 IBM Corp. and others. All rights reserved.
 This file is made available under the terms of the Common Public License v1.0
 which accompanies this distribution, and is available at
 http://www.eclipse.org/legal/cpl-v10.html
 �
 Contributors:
 **********************************************************************/

/**
 * Responsible for expanding a variable into text format.
 * <p>
 * Implementation of this interface will be treated like a singleton. That is,
 * only one instance will be created per variable extension.
 * </p>
 * <p>
 * This interface is not to be extended by clients. Clients may implement this
 * interface.
 * </p>
 */
public interface IVariableTextExpander {
	/**
	 * Returns the expanded text for the given variable tag and value.
	 * 
	 * @param varTag
	 *            the variable tag name
	 * @param varValue
	 *            the value for the variable
	 * @param context
	 *            the context the variable should use to expand itself
	 * @return the text of the expanded variable or <code>null</code> if not
	 *         possible
	 */
	public String getText(String varTag, String varValue,
			ExpandVariableContext context);
}