beagled/CalendarQueryable/ICalParser/ICalUtil.cs

   1 using System;
   2 using System.IO;
   3 using System.Text;
   4
   5 /***
   6  * <copyright>
   7  *   ICalParser is a general purpose .Net parser for iCalendar format files (RFC 2445)
   8  *
   9  *   Copyright (C) 2004  J. Tim Spurway
  10  *
  11  *   This program is free software; you can redistribute it and/or modify
  12  *   it under the terms of the GNU General Public License as published by
  13  *   the Free Software Foundation; either version 2 of the License, or
  14  *   (at your option) any later version.
  15  *
  16  *   This program is distributed in the hope that it will be useful,
  17  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  *   GNU General Public License for more details.
  20  *
  21  *   You should have received a copy of the GNU General Public License
  22  *   along with this program; if not, write to the Free Software
  23  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24  * </copyright>
  25  */
  26
  27 namespace Semaview.Shared.ICalParser
  28 {
  29     /// <summary>
  30     /// Summary description for ICalUtil.
  31     /// </summary>
  32     public class ICalUtil
  33     {
  34         private ICalUtil()
  35         {
  36         }
  37
  38         /**
  39          * From RFC2445
  40          *
  41          * Lines of text SHOULD NOT be longer than 75 octets, excluding the line
  42          * break. Long content lines SHOULD be split into a multiple line
  43          * representations using a line "folding" technique. That is, a long
  44          * line can be split between any two characters by inserting a CRLF
  45          * immediately followed by a single linear white space character (i.e.,
  46          * SPACE, US-ASCII decimal 32 or HTAB, US-ASCII decimal 9). Any sequence
  47          * of CRLF followed immediately by a single linear white space character
  48          * is ignored (i.e., removed) when processing the content type.
  49          *
  50          * For example the line:
  51          *
  52          *   DESCRIPTION:This is a long description that exists on a long line.
  53          *
  54          * Can be represented as:
  55          *
  56          *   DESCRIPTION:This is a lo
  57          *    ng description
  58          *    that exists on a long line.
  59          *
  60          **/
  61         public static string FoldLines( StringBuilder iCal )
  62         {
  63             StringReader  reader = new StringReader( iCal.ToString() );
  64             StringBuilder folded = new StringBuilder();
  65             string line = reader.ReadLine();
  66             while( line != null )
  67             {
  68                 int start = 0;
  69                 int len   = line.Length;
  70
  71                 // I chose 72 instead of the max 75 cause I wanted to, so :P
  72                 while( len > 72 )
  73                 {
  74                     // Indent if not first line
  75                     if( start != 0 )
  76                         folded.Append( " " );
  77                     folded.AppendFormat( "{0}\r\n", line.Substring( start, 72 ) );
  78                     start += 72;
  79                     len   -= 72;
  80                 }
  81                 // Indent if not first line
  82                 if( start != 0 )
  83                     folded.Append( " " );
  84                 folded.AppendFormat( "{0}\r\n", line.Substring( start, len ) );
  85                 line = reader.ReadLine();
  86             }
  87             return folded.ToString();
  88         }
  89
  90         /// <summary>
  91         /// Quotes newlines, tabs, commas, colons, semi-colons, double quotes and back slashes
  92         /// </summary>
  93         /// <param name="str"></param>
  94         /// <returns></returns>
  95         public static string Quote( string str )
  96         {
  97             string quoted = str.Replace( "\\", "\\\\" );
  98             quoted = quoted.Replace( "\r\n", "\\n" );
  99             quoted = quoted.Replace( "\n", "\\n" );
 100             quoted = quoted.Replace( "\t", "\\t" );
 101             quoted = quoted.Replace( ",", "\\," );
 102             quoted = quoted.Replace( ":", "\\:" );
 103             quoted = quoted.Replace( ";", "\\;" );
 104             quoted = quoted.Replace( "\"", "\\\"" );
 105             return quoted;
 106         }
 107
 108         public static string Unquote( string str )
 109         {
 110             string unquoted = str.Replace( "\\r\\n", "\r\n" );
 111             unquoted = unquoted.Replace( "\\n", "\r\n" );
 112             unquoted = unquoted.Replace( "\\t", "\t" );
 113             unquoted = unquoted.Replace( "\\,", "," );
 114             unquoted = unquoted.Replace( "\\:", ":" );
 115             unquoted = unquoted.Replace( "\\;", ";" );
 116             unquoted = unquoted.Replace( "\\\"", "\"" );
 117             unquoted = unquoted.Replace( "\\\\", "\\" );
 118             return unquoted.ToString();
 119         }
 120     }
 121 }