/**
 * The contents of this file are subject to the OpenMRS Public License
 * Version 1.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://license.openmrs.org
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
 * License for the specific language governing rights and limitations
 * under the License.
 *
 * Copyright (C) OpenMRS, LLC.  All Rights Reserved.
 */
package org.openmrs.customdatatype;

import java.io.OutputStream;


/**
 * Indicates that a CustomDatatypeHandler allows underlying custom values to be downloaded or streamed in some
 * meaningful way.
 */
public interface DownloadableDatatypeHandler<T> extends CustomDatatypeHandler<CustomDatatype<T>, T> {
	
	/**
     * @param dt the datatype this handler handles
     * @param valueReference custom value to be downloaded
     * @return the MIME type that should be communicated to any client downloading the given custom value.
     * Should not return null.
     */
    String getMimeType(CustomDatatype<T> dt, String valueReference);

    /**
     * @param dt the datatype this handler handles
     * @param valueReference custom value to be downloaded
     * @return the filename that should be communicated to any client downloading the given custom value.
     * May return null, in which case the framework will choose a meaningless filename.
     */
    String getFilename(CustomDatatype<T> dt, String valueReference);
	
	/**
     * Writes the custom value to os. Implementations should assume that the caller has set up the stream,
     * calling getMimeType and getFilename if necessary.
     * Implementations should assume that the caller has taken care of any needed buffering on os.
     * 
     * @param dt the datatype this handler handles 
     * @param valueReference custom value to be written to os 
     * @param os the output stream to be written to
     */
    void writeToStream(CustomDatatype<T> dt, String valueReference, OutputStream os);
	
}

Add DownloadableDatatypeHandler interface - TRUNK-3037