/source/library/Interlace/PropertyLists/Writer.cs

#region Using Directives and Copyright Notice



// Copyright (c) 2007-2010, Computer Consultancy Pty Ltd

// All rights reserved.

// 

// Redistribution and use in source and binary forms, with or without

// modification, are permitted provided that the following conditions are met:

//     * Redistributions of source code must retain the above copyright

//       notice, this list of conditions and the following disclaimer.

//     * Redistributions in binary form must reproduce the above copyright

//       notice, this list of conditions and the following disclaimer in the

//       documentation and/or other materials provided with the distribution.

//     * Neither the name of the Computer Consultancy Pty Ltd nor the

//       names of its contributors may be used to endorse or promote products

//       derived from this software without specific prior written permission.

// 

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 

// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 

// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 

// ARE DISCLAIMED. IN NO EVENT SHALL COMPUTER CONSULTANCY PTY LTD BE LIABLE 

// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 

// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 

// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 

// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 

// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 

// OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH

// DAMAGE.



using System;

using System.Collections.Generic;

using System.Text;

using System.Text.RegularExpressions;



#endregion



namespace Interlace.PropertyLists

{

    class Writer

    {

        StringBuilder _builder = new StringBuilder();

        const int _indentSpaces = 4;

        int _currentIndentLevel = 0;

        bool _atLineStart = true;



        Regex _isPlainString = new Regex("^[A-Za-z]+$");

        Regex _isTrue = new Regex("^true$");

        Regex _isFalse = new Regex("^false$");

        Regex _isQuotableCharacter = new Regex("(\\n|\"|\\\\)");



        void EnsureIndentWritten()

        {

            if (_atLineStart)

            {

                _builder.Append("".PadLeft(_currentIndentLevel * _indentSpaces));



                _atLineStart = false;

            }

        }



        void Append(string format, params object[] args)

        {

            EnsureIndentWritten();

            _builder.Append(string.Format(format, args));

        }



        void AppendLine(string format, params object[] args)

        {

            EnsureIndentWritten();

            _builder.AppendLine(string.Format(format, args));

            _atLineStart = true;

        }



        void Indent()

        {

            _currentIndentLevel++;

        }



        void Dedent()

        {

            _currentIndentLevel--;

        }



        string ReplaceQuotedCharacter(Match match)

        {

            switch (match.Groups[1].Value)

            {

                case "\n":

                    return "\\n";

                case "\\":

                    return "\\\\";

                case "\"":

                    return "\\\"";

                default:

                    throw new InvalidOperationException();

            }

        }



        void WriteObject(object obj)

        {

            if (obj is string)

            {

                string str = (string)obj;



                // If it's not a plain string, it needs quoting.  The strings "true" and "false" also

                // need quoting so they aren't parsed back in as booleans.

                if (_isPlainString.IsMatch(str) && !_isTrue.IsMatch(str) && !_isFalse.IsMatch(str))

                {

                    Append((string)obj);

                }

                else

                {

                    Append("\"{0}\"", _isQuotableCharacter.Replace(str, ReplaceQuotedCharacter));

                }

            }

            else if (obj is int || obj is byte || obj is short)

            {

                Append("{0}", Convert.ToInt32(obj));

            }

            else if (obj is double)

            {

                Append("{0}", Convert.ToDouble(obj));

            }

            else if (obj is bool)

            {

                Append("{0}", obj.ToString().ToLower());

            }

            else if (obj is PropertyDictionary)

            {

                WriteDictionary(obj as PropertyDictionary);

            }

            else if (obj is PropertyArray)

            {

                WriteArray(obj as PropertyArray);

            }

            else if (obj is DateTime)

            {

                Append("\"{0}\"", ((DateTime)obj).ToUniversalTime().ToString("s"));

            }

            else

            {

                throw new NotImplementedException(

                    "Only strings, integers, and other property dictionaries can be persisted.");

            }

        }



        public void WriteArray(PropertyArray array)

        {

            AppendLine("{0}", "(");

            Indent();



            for (int i = 0; i < array.Count; i++)

            {

                WriteObject(array[i]);

                if (i != array.Count - 1) AppendLine(", ");

            }



            Dedent();

            Append("{0}", ")");

        }



        public void WriteDictionary(PropertyDictionary dictionary)

        {

            AppendLine("{0}", "{");

            Indent();



            foreach (object key in dictionary.Keys)

            {

                object value = dictionary.ValueFor(key);



                if (value == null) continue;



                WriteObject(key);

                Append(" = ");

                WriteObject(value);

                AppendLine(";");

            }



            Dedent();

            Append("{0}", "}");

        }



        public override string ToString()

        {

            return _builder.ToString();

        }

    }

}