    001    // Copyright 2007, 2008, 2010 The Apache Software Foundation
    002    //
    003    // Licensed under the Apache License, Version 2.0 (the "License");
    004    // you may not use this file except in compliance with the License.
    005    // You may obtain a copy of the License at
    006    //
    007    // http://www.apache.org/licenses/LICENSE-2.0
    008    //
    009    // Unless required by applicable law or agreed to in writing, software
    010    // distributed under the License is distributed on an "AS IS" BASIS,
    011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    012    // See the License for the specific language governing permissions and
    013    // limitations under the License.
    014
    015    package org.apache.tapestry5.internal.services;
    016
    017    import java.io.IOException;
    018    import java.io.PrintWriter;
    019
    020    import org.apache.tapestry5.ContentType;
    021    import org.apache.tapestry5.SymbolConstants;
    022    import org.apache.tapestry5.internal.InternalConstants;
    023    import org.apache.tapestry5.ioc.annotations.Symbol;
    024    import org.apache.tapestry5.json.JSONObject;
    025    import org.apache.tapestry5.services.ComponentEventResultProcessor;
    026    import org.apache.tapestry5.services.Response;
    027
    028    /**
    029     * Implementation of {@link ComponentEventResultProcessor} for {@link org.apache.tapestry5.json.JSONObject}, allowing a
    030     * component event handler to return a JSONObject that will be sent directly to the client as the reply. This is often
    031     * used with custom components that need a custom JSON response.
    032     */
    033    public class JSONObjectEventResultProcessor implements ComponentEventResultProcessor<JSONObject>
    034    {
    035        private final Response response;
    036
    037        private final String outputEncoding;
    038
    039        private final boolean compactJSON;
    040
    041        public JSONObjectEventResultProcessor(Response response,
    042
    043        @Symbol(SymbolConstants.CHARSET)
    044        String outputEncoding,
    045
    046        @Symbol(SymbolConstants.COMPACT_JSON)
    047        boolean compactJSON)
    048        {
    049            this.response = response;
    050            this.outputEncoding = outputEncoding;
    051            this.compactJSON = compactJSON;
    052        }
    053
    054        public void processResultValue(JSONObject value) throws IOException
    055        {
    056            ContentType contentType = new ContentType(InternalConstants.JSON_MIME_TYPE, outputEncoding);
    057
    058            PrintWriter pw = response.getPrintWriter(contentType.toString());
    059
    060            value.print(pw, compactJSON);
    061
    062            pw.close();
    063        }
    064    }