Util/ICalParser.cs

   1 //
   2 // ICalParser.cs
   3 //
   4 // Copyright (C) 2006 Novell, Inc.
   5 //
   6
   7 //
   8 // Permission is hereby granted, free of charge, to any person obtaining a copy
   9 // of this software and associated documentation files (the "Software"), to deal
  10 // in the Software without restriction, including without limitation the rights
  11 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  12 // copies of the Software, and to permit persons to whom the Software is
  13 // furnished to do so, subject to the following conditions:
  14 //
  15 // The above copyright notice and this permission notice shall be included in all
  16 // copies or substantial portions of the Software.
  17 //
  18 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  21 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  23 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  24 // SOFTWARE.
  25 //
  26
  27 using System;
  28 using System.IO;
  29 using System.Text;
  30 using System.Collections;
  31
  32 namespace Beagle.Util
  33 {
  34         public class ICalParser : IEnumerator
  35         {
  36                 public static string KabcMimeType = "text/x-kabc-directory";
  37                 public static string KnotesMimeType = "text/x-knotes-calendar";
  38
  39                 private ParserState state = ParserState.ParsingProperty;
  40                 private StringBuilder buffer = new StringBuilder ();
  41
  42                 private Token current;
  43                 private TextReader reader;
  44
  45                 public ICalParser (TextReader reader)
  46                 {
  47                         this.reader = new UnfoldingTextReader (reader);
  48                 }
  49
  50                 public object Current
  51                 {
  52                         get { return current; }
  53                 }
  54
  55                 public bool MoveNext ()
  56                 {
  57                         string data;
  58                         char stop;
  59
  60                         switch (state) {
  61                         case ParserState.ParsingProperty:
  62                                 data = Read (new char [] { ':', ';' }, out stop);
  63
  64                                 if (data == null)
  65                                         return false;
  66
  67                                 switch (stop) {
  68                                 case ':':
  69                                         state = ParserState.ParsingPropertyValue;
  70                                         break;
  71                                 case ';':
  72                                         state = ParserState.ParsingPropertyParameter;
  73                                         break;
  74                                 }
  75
  76                                 current = new Token (TokenType.Property, data.Trim ());
  77                                 break;
  78                         case ParserState.ParsingPropertyValue:
  79                                 data = Read (new char[] { '\n'}, out stop);
  80
  81                                 if (data == null)
  82                                         return false;
  83
  84                                 switch (stop) {
  85                                 case '\n':
  86                                         state = ParserState.ParsingProperty;
  87                                         break;
  88                                 case ',':
  89                                         state = ParserState.ParsingPropertyValue;
  90                                         break;
  91                                 }
  92
  93                                 current = new Token (TokenType.PropertyValue, data.Trim ());
  94                                 break;
  95                         case ParserState.ParsingPropertyParameter:
  96                                 data = Read (new char[] { '\n', '=', ';', ','}, out stop);
  97
  98                                 if (data == null)
  99                                         return false;
 100
 101                                 switch (stop) {
 102                                 case '=':
 103                                         state = ParserState.ParsingPropertyParameterValue;
 104                                         break;
 105                                 case '\n':
 106                                         state = ParserState.ParsingProperty;
 107                                         break;
 108                                 case ';':
 109                                 case ',':
 110                                         break;
 111                                 }
 112
 113                                 current = new Token (TokenType.PropertyParameter, data.Trim ());
 114                                 break;
 115                         case ParserState.ParsingPropertyParameterValue:
 116                                 data = Read (new char[] { ',', ':', ';' }, out stop);
 117
 118                                 switch (stop) {
 119                                 case ';':
 120                                         state = ParserState.ParsingPropertyParameter;
 121                                         break;
 122                                 case ':':
 123                                         state = ParserState.ParsingPropertyValue;
 124                                         break;
 125                                 case ',':
 126                                         break;
 127                                 }
 128
 129                                 current = new Token (TokenType.PropertyParameterValue, data.Trim ());
 130                                 break;
 131                         }
 132
 133                         return true;
 134                 }
 135
 136                 public void Reset()
 137                 {
 138                         throw new NotImplementedException ();
 139                 }
 140
 141                 public void Dispose()
 142                 {
 143
 144                 }
 145
 146                 private string Read (char[] stops, out char stop)
 147                 {
 148                         stop = (char) 0;
 149
 150                         lock (buffer) {
 151                                 int i;
 152                                 buffer.Length = 0;
 153
 154                                 while ((i = reader.Read ()) != -1) {
 155                                         if (Array.IndexOf (stops, (char) i) != -1) {
 156                                                 stop = (char) i;
 157                                                 break;
 158                                         }
 159
 160                                         buffer.Append((char)i);
 161                                 }
 162
 163                                 return (buffer.Length == 0) ? null : buffer.ToString ();
 164                         }
 165                 }
 166
 167                 public class Token
 168                 {
 169                         private TokenType type;
 170                         private string value;
 171
 172                         public TokenType Type
 173                         {
 174                                 get { return type; }
 175                         }
 176
 177                         public string Value
 178                         {
 179                                 get { return value; }
 180                         }
 181
 182                         public Token (TokenType type, string value)
 183                         {
 184                                 this.type = type;
 185                                 this.value = value;
 186                         }
 187
 188                         public override string ToString ()
 189                         {
 190                                 return String.Format ("{0} ({1})", type, value);
 191                         }
 192                 }
 193
 194                 public enum TokenType
 195                 {
 196                         Property,
 197                         PropertyValue,
 198                         PropertyParameter,
 199                         PropertyParameterValue,
 200                 }
 201
 202                 private enum ParserState
 203                 {
 204                         ParsingProperty,
 205                         ParsingPropertyValue,
 206                         ParsingPropertyParameter,
 207                         ParsingPropertyParameterValue
 208                 }
 209
 210                 private class UnfoldingTextReader : TextReader
 211                 {
 212                         private TextReader reader;
 213
 214                         public UnfoldingTextReader(TextReader reader)
 215                         {
 216                                 this.reader = reader;
 217                         }
 218
 219                         public override int Read ()
 220                         {
 221                                 int i = reader.Read ();
 222
 223                                 if (i == '\r')
 224                                         i = reader.Read ();
 225
 226                                 if ((char) i == '\n' && (char) reader.Peek() == ' ') {
 227                                         do {
 228                                                 i = reader.Read ();
 229
 230                                                 if ((char) i == '\r')
 231                                                         i = reader.Read ();
 232                                         } while ((char) i == ' ' || (char) i == '\n');
 233                                 }
 234                                 return i;
 235                         }
 236                 }
 237         }
 238
 239 #if false
 240         class Driver
 241         {
 242                 static void Main (string [] args)
 243                 {
 244                         ICalParser parser = new ICalParser (File.OpenText ("test.ical"));
 245
 246                         while (parser.MoveNext()) {
 247                                 ICalParser.Token token = (ICalParser.Token) parser.Current;
 248
 249                                 if (token.Type != ICalParser.TokenType.Property)
 250                                         Console.Write ("\t");
 251
 252                                 if (token.Type == ICalParser.TokenType.PropertyParameterValue)
 253                                         Console.Write ("\t");
 254
 255                                 Console.WriteLine (token);
 256                         }
 257                 }
 258         }
 259 #endif
 260 }