JsonCommand.java

// Copyright 2013 Michel Kraemer
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package de.undercouch.citeproc.tool;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.List;

import de.undercouch.citeproc.ItemDataProvider;
import de.undercouch.citeproc.csl.CSLItemData;
import de.undercouch.citeproc.helper.json.JsonBuilder;
import de.undercouch.citeproc.helper.json.StringJsonBuilderFactory;
import de.undercouch.underline.InputReader;

/**
 * CLI command that converts input bibliographies to JSON files
 * @author Michel Kraemer
 */
public class JsonCommand extends CitationIdsCommand {
	@Override
	public String getUsageName() {
		return "json";
	}
	
	@Override
	public String getUsageDescription() {
		return "Convert input bibliography to JSON";
	}
	
	@Override
	public int doRun(String[] remainingArgs, InputReader in, PrintWriter out)
			throws IOException {
		int ret = super.doRun(remainingArgs, in, out);
		if (ret != 0) {
			return ret;
		}
		
		//run conversion
		generateJSON(getCitationIds(), getProvider(), out);
		
		return 0;
	}
	
	/**
	 * Generates JSON
	 * @param citationIds the citation ids given on the command line
	 * @param provider a provider containing all citation item data
	 * @param out the print stream to write the output to
	 */
	private void generateJSON(List<String> citationIds, ItemDataProvider provider,
			PrintWriter out) {
		StringJsonBuilderFactory factory = new StringJsonBuilderFactory();
		//create an array of citation item data objects (either for
		//the whole bibliography or for the given citation ids only)
		out.print("[");
		List<String> ids = citationIds;
		if (ids.isEmpty()) {
			ids = Arrays.asList(provider.getIds());
		}
		
		int i = 0;
		for (String id : ids) {
			if (i > 0) {
				out.print(",");
			}
			CSLItemData item = provider.retrieveItem(id);
			JsonBuilder b = factory.createJsonBuilder();
			out.print(item.toJson(b));
			++i;
		}
		
		out.println("]");
	}
}