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