mcs/class/System.Web/System.Web.WebUtils/UrlUtils.cs

   1 /**\r
   2  * Namespace: System.Web.UI.WebUtils\r
   3  * Class:     UrlUtils\r
   4  * \r
   5  * Author:  Gaurav Vaish\r
   6  * Contact: <gvaish@iitk.ac.in>\r
   7  * Status:  10??%\r
   8  * \r
   9  * (C) Gaurav Vaish (2001)\r
  10  */\r
  11 \r
  12 using System;\r
  13 \r
  14 namespace System.Web.UI.WebUtils\r
  15 {\r
  16         internal class UrlUtils\r
  17         {\r
  18                 /*\r
  19                  * I could not find these functions in the class System.Uri\r
  20                  * Besides, an instance of Uri will not be formed until and unless the address is of\r
  21                  * the form protocol://[user:pass]host[:port]/[fullpath]\r
  22                  * ie, a protocol, and that too without any blanks before,\r
  23                  * is a must which may not be the case here.\r
  24                  * Important: Escaped URL is assumed here. nothing like .aspx?path=/something\r
  25                  * It should be .aspx?path=%2Fsomething\r
  26                  */\r
  27                 public static string GetProtocol(string url)\r
  28                 {\r
  29                         //Taking code from Java Class java.net.URL\r
  30                         if(url!=null)\r
  31                         {\r
  32                                 if(url.Length>0)\r
  33                                 {\r
  34                                         \r
  35                                         int i, start = 0, limit;\r
  36                                         limit = url.Length;\r
  37                                         char c;\r
  38                                         bool aRef = false;\r
  39                                         while( (limit > 0) && (url[limit-1] <= ' '))\r
  40                                         {\r
  41                                                 limit --;\r
  42                                         }\r
  43                                         while( (start < limit) && (url[start] <= ' '))\r
  44                                         {\r
  45                                                 start++;\r
  46                                         }\r
  47                                         if(RegionMatches(true, url, start, "url:", 0, 4))\r
  48                                         {\r
  49                                                 start += 4;\r
  50                                         }\r
  51                                         if(start < url.Length && url[start]=='#')\r
  52                                         {\r
  53                                                 aRef = true;\r
  54                                         }\r
  55                                         for(i = start; !aRef && (i < limit) && ((c=url[i]) != '/'); i++)\r
  56                                         {\r
  57                                                 if(c==':')\r
  58                                                 {\r
  59                                                         return url.Substring(start, i - start);\r
  60                                                 }\r
  61                                         }\r
  62                                 }\r
  63                         }\r
  64                         return String.Empty;\r
  65                 }\r
  66                 \r
  67                 public static bool IsRootUrl(string url)\r
  68                 {\r
  69                         if(url!=null)\r
  70                         {\r
  71                                 if(url.Length>0)\r
  72                                 {\r
  73                                         return IsValidProtocol(GetProtocol(url).ToLower());\r
  74                                 }\r
  75                         }\r
  76                         return false;\r
  77                 }\r
  78                 \r
  79                 public static bool IsValidProtocol(string protocol)\r
  80                 {\r
  81                         if(protocol.Length < 1)\r
  82                                 return false;\r
  83                         char c = protocol[0];\r
  84                         if(!Char.IsLetter(c))\r
  85                         {\r
  86                                 System.Console.WriteLine("Character {0} is not a letter.", c);\r
  87                                 return false;\r
  88                         }\r
  89                         for(int i=1; i < protocol.Length; i++)\r
  90                         {\r
  91                                 c = protocol[i];\r
  92                                 if(!Char.IsLetterOrDigit(c) && c!='.' && c!='+' && c!='-')\r
  93                                 {\r
  94                                         System.Console.WriteLine("Character \"{0}\" is not a letter or a digit or something.", c);\r
  95                                         return false;\r
  96                                 }\r
  97                         }\r
  98                         return true;\r
  99                 }\r
 100                 \r
 101                 /*\r
 102                  * MakeRelative("http://www.foo.com/bar1/bar2/file","http://www.foo.com/bar1")\r
 103                  * will return "bar2/file"\r
 104                  * while MakeRelative("http://www.foo.com/bar1/...","http://www.anotherfoo.com")\r
 105                  * return 'null' and so does the call\r
 106                  * MakeRelative("http://www.foo.com/bar1/bar2","http://www.foo.com/bar")\r
 107                  */\r
 108                 public static string MakeRelative(string fullUrl, string relativeTo)\r
 109                 {\r
 110                         //Uri fromUri;\r
 111                         //Uri toUri;\r
 112                         if(fullUrl==relativeTo)\r
 113                         {\r
 114                                 return String.Empty;\r
 115                         }\r
 116                         if(fullUrl.IndexOf(relativeTo)!=0)\r
 117                         {\r
 118                                 return null;\r
 119                         }\r
 120                         string leftOver = fullUrl.Substring(relativeTo.Length);\r
 121                         if(!fullUrl.EndsWith("/") && !leftOver.StartsWith("/"))\r
 122                         {\r
 123                                 return null;\r
 124                         }\r
 125                         if(leftOver.StartsWith("/"))\r
 126                         {\r
 127                                 leftOver = leftOver.Substring(1);\r
 128                         }\r
 129                         return leftOver;\r
 130                 }\r
 131                 \r
 132                 /*\r
 133                  * Check JavaDocs for java.lang.String#RegionMatches(bool, int, String, int, int)\r
 134                  * Could not find anything similar in the System.String class\r
 135                  */\r
 136                 public static bool RegionMatches(bool ignoreCase, string source, int start, string match, int offset, int len)\r
 137                 {\r
 138                         if(source!=null || match!=null)\r
 139                         {\r
 140                                 if(source.Length>0 && match.Length>0)\r
 141                                 {\r
 142                                         char[] ta = source.ToCharArray();\r
 143                                         char[] pa = match.ToCharArray();\r
 144                                         if((offset < 0) || (start < 0) || (start > (source.Length - len)) || (offset > (match.Length - len)))\r
 145                                         {\r
 146                                                 return false;\r
 147                                         }\r
 148                                         while(len-- > 0)\r
 149                                         {\r
 150                                                 char c1 = ta[start++];\r
 151                                                 char c2 = pa[offset++];\r
 152                                                 if(c1==c2)\r
 153                                                         continue;\r
 154                                                 if(ignoreCase)\r
 155                                                 {\r
 156                                                         if(Char.ToUpper(c1)==Char.ToUpper(c2))\r
 157                                                                 continue;\r
 158                                                         // Check for Gregorian Calendar where the above may not hold good\r
 159                                                         if(Char.ToLower(c1)==Char.ToLower(c2))\r
 160                                                                 continue;\r
 161                                                 }\r
 162                                                 return false;\r
 163                                         }\r
 164                                         return true;\r
 165                                 }\r
 166                         }\r
 167                         return false;\r
 168                 }\r
 169                 \r
 170                 public static string GetDirectory(string url)\r
 171                 {\r
 172                         if(url==null)\r
 173                         {\r
 174                                 return null;\r
 175                         }\r
 176                         if(url.Length==0)\r
 177                         {\r
 178                                 return String.Empty;\r
 179                         }\r
 180                         url.Replace('\\','/');\r
 181                         string baseDir = url.Substring(0, url.LastIndexOf('/'));\r
 182                         if(baseDir.Length==0)\r
 183                         {\r
 184                                 baseDir = "/";\r
 185                         }\r
 186                         return baseDir;\r
 187                 }\r
 188         }\r
 189 }\r