001// Copyright 2010, 2013 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
015package org.apache.tapestry5.json;
016
017import java.io.CharArrayWriter;
018import java.io.PrintWriter;
019import java.io.Serializable;
020
021/**
022 * Base class for {@link JSONArray} and {@link JSONObject} that exists to organize the code
023 * for printing such objects (either compact or pretty).
024 * 
025 * @since 5.2.0
026 */
027public abstract class JSONCollection implements Serializable
028{
029    /**
030     * Converts this JSON collection into a parsable string representation.
031     * <p/>
032     * Warning: This method assumes that the data structure is acyclical.
033     * <p>
034     * Starting in release 5.2, the result will be pretty printed for readability.
035     * 
036     * @return a printable, displayable, portable, transmittable representation of the object, beginning with
037     *         <code>{</code>&nbsp;<small>(left brace)</small> and ending with <code>}</code>&nbsp;<small>(right
038     *         brace)</small>.
039     */
040    @Override
041    public String toString()
042    {
043        CharArrayWriter caw = new CharArrayWriter();
044        PrintWriter pw = new PrintWriter(caw);
045
046        JSONPrintSession session = new PrettyPrintSession(pw);
047
048        print(session);
049
050        pw.close();
051
052        return caw.toString();
053    }
054
055    /**
056     * Converts the JSONObject to a compact or pretty-print string representation
057     * 
058     * @param compact
059     *            if true, return minimal format string.
060     * @since 5.2.0
061     */
062    public String toString(boolean compact)
063    {
064        return compact ? toCompactString() : toString();
065    }
066
067    /**
068     * Prints the JSONObject as a compact string (not extra punctuation). This is, essentially, what
069     * Tapestry 5.1 did inside {@link #toString()}.
070     */
071    public String toCompactString()
072    {
073        CharArrayWriter caw = new CharArrayWriter();
074        PrintWriter pw = new PrintWriter(caw);
075
076        print(pw);
077
078        pw.close();
079
080        return caw.toString();
081    }
082
083    /**
084     * Prints the JSONObject to the write (compactly or not).
085     * 
086     * @param writer
087     *            to write content to
088     * @param compact
089     *            if true, then write compactly, if false, write with pretty printing
090     * @since 5.2.1
091     */
092    public void print(PrintWriter writer, boolean compact)
093    {
094        JSONPrintSession session = compact ? new CompactSession(writer) : new PrettyPrintSession(writer);
095
096        print(session);
097    }
098
099    /**
100     * Prints the JSONObject to the writer compactly (with no extra whitespace).
101     */
102    public void print(PrintWriter writer)
103    {
104        print(writer, true);
105    }
106
107    /**
108     * Prints the JSONObject to the writer using indentation (two spaces per indentation level).
109     */
110    public void prettyPrint(PrintWriter writer)
111    {
112        print(writer, false);
113    }
114
115    /**
116     * Print the collection in a parsable format using the session to (optionally) inject extra
117     * whitespace (for "pretty printing").
118     */
119    abstract void print(JSONPrintSession session);
120}