    001// Licensed under the Apache License, Version 2.0 (the "License");
    002// you may not use this file except in compliance with the License.
    003// You may obtain a copy of the License at
    004//
    005// http://www.apache.org/licenses/LICENSE-2.0
    006//
    007// Unless required by applicable law or agreed to in writing, software
    008// distributed under the License is distributed on an "AS IS" BASIS,
    009// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    010// See the License for the specific language governing permissions and
    011// limitations under the License.
    012
    013package org.apache.tapestry5.json;
    014
    015import java.io.CharArrayWriter;
    016import java.io.PrintWriter;
    017import java.io.Serializable;
    018
    019/**
    020 * Base class for {@link JSONArray} and {@link JSONObject} that exists to organize the code
    021 * for printing such objects (either compact or pretty).
    022 *
    023 * @since 5.2.0
    024 */
    025public abstract class JSONCollection implements Serializable
    026{
    027    /**
    028     * Converts this JSON collection into a parsable string representation.
    029     *
    030     * Warning: This method assumes that the data structure is acyclical.
    031     *
    032     * Starting in release 5.2, the result will be pretty printed for readability.
    033     *
    034     * @return a printable, displayable, portable, transmittable representation of the object, beginning with
    035     *         <code>{</code>&nbsp;<small>(left brace)</small> and ending with <code>}</code>&nbsp;<small>(right
    036     *         brace)</small>.
    037     */
    038    @Override
    039    public String toString()
    040    {
    041        CharArrayWriter caw = new CharArrayWriter();
    042        PrintWriter pw = new PrintWriter(caw);
    043
    044        JSONPrintSession session = new PrettyPrintSession(pw);
    045
    046        print(session);
    047
    048        pw.close();
    049
    050        return caw.toString();
    051    }
    052
    053    /**
    054     * Converts the JSONObject to a compact or pretty-print string representation
    055     *
    056     * @param compact
    057     *            if true, return minimal format string.
    058     * @since 5.2.0
    059     */
    060    public String toString(boolean compact)
    061    {
    062        return compact ? toCompactString() : toString();
    063    }
    064
    065    /**
    066     * Prints the JSONObject as a compact string (not extra punctuation). This is, essentially, what
    067     * Tapestry 5.1 did inside {@link #toString()}.
    068     */
    069    public String toCompactString()
    070    {
    071        CharArrayWriter caw = new CharArrayWriter();
    072        PrintWriter pw = new PrintWriter(caw);
    073
    074        print(pw);
    075
    076        pw.close();
    077
    078        return caw.toString();
    079    }
    080
    081    /**
    082     * Prints the JSONObject to the write (compactly or not).
    083     *
    084     * @param writer
    085     *            to write content to
    086     * @param compact
    087     *            if true, then write compactly, if false, write with pretty printing
    088     * @since 5.2.1
    089     */
    090    public void print(PrintWriter writer, boolean compact)
    091    {
    092        JSONPrintSession session = compact ? new CompactSession(writer) : new PrettyPrintSession(writer);
    093
    094        print(session);
    095    }
    096
    097    /**
    098     * Prints the JSONObject to the writer compactly (with no extra whitespace).
    099     */
    100    public void print(PrintWriter writer)
    101    {
    102        print(writer, true);
    103    }
    104
    105    /**
    106     * Prints the JSONObject to the writer using indentation (two spaces per indentation level).
    107     */
    108    public void prettyPrint(PrintWriter writer)
    109    {
    110        print(writer, false);
    111    }
    112
    113    /**
    114     * Print the collection in a parsable format using the session to (optionally) inject extra
    115     * whitespace (for "pretty printing").
    116     */
    117    abstract void print(JSONPrintSession session);
    118}