mcs/class/System.XML/Mono.Xml.Xsl.Operations/XslAvt.cs

   1 //
   2 // XslAvt.cs
   3 //
   4 // Author:
   5 //      Ben Maurer (bmaurer@users.sourceforge.net)
   6 //
   7 // (C) 2003 Ben Maurer
   8 //
   9
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29 //
  30
  31 using System;
  32 using System.Collections;
  33 using System.IO;
  34 using System.Text;
  35 using System.Xml;
  36 using System.Xml.XPath;
  37 using System.Xml.Xsl;
  38
  39 namespace Mono.Xml.Xsl.Operations {
  40         // Represents an Attribute Value Template in XSL.
  41         internal class XslAvt {
  42
  43                 string simpleString;
  44                 ArrayList avtParts;
  45
  46                 public XslAvt (string str, Compiler comp) {
  47                         if (str.IndexOf ("{") == -1 && str.IndexOf ("}") == -1) {
  48                                 // That was easy ;-).
  49                                 simpleString = str;
  50                                 return;
  51                         }
  52                         avtParts = new ArrayList ();
  53                         StringBuilder sb = new StringBuilder ();
  54                         StringReader r = new StringReader (str);
  55
  56
  57
  58                         while (r.Peek () != -1) {
  59                                 char c = (char)r.Read ();
  60                                 switch (c) {
  61                                 case '{':
  62                                         if ((char)r.Peek () == '{') {
  63                                                 // {{ == escaped {
  64                                                 sb.Append ((char)r.Read ());
  65                                                 break;
  66                                         }
  67
  68                                         if (sb.Length != 0) {
  69                                                 // Ok, we have already found a text
  70                                                 // part, lets save that.
  71                                                 avtParts.Add (new SimpleAvtPart (sb.ToString ()));
  72                                                 sb.Length = 0;
  73                                         }
  74
  75                                         while ((c = (char)r.Read ()) != '}') {
  76                                                 switch (c) {
  77                                                 case '\'': case '"': {
  78                                                         // We are inside a quote
  79                                                         char unq = c;
  80                                                         sb.Append (c);
  81                                                         while ((c = (char)r.Read ()) != unq) {
  82                                                                 sb.Append (c);
  83                                                                 if (r.Peek () == -1)
  84                                                                         throw new XsltCompileException ("unexpected end of AVT", null, comp.Input);
  85                                                         }
  86
  87
  88                                                         sb.Append (c);
  89                                                         break;
  90                                                 } // ' or "
  91                                                 default:
  92                                                         sb.Append (c);
  93                                                         break;
  94                                                 }
  95                                                 if (r.Peek () == -1) throw new XsltCompileException ("unexpected end of AVT", null, comp.Input);
  96                                         }
  97
  98
  99                                         avtParts.Add (new XPathAvtPart (comp.CompileExpression (sb.ToString ())));
 100                                         sb.Length = 0;
 101                                         break;
 102                                 case '}':
 103                                         c = (char)r.Read ();
 104                                         if (c != '}')
 105                                                 throw new XsltCompileException ("Braces must be escaped", null, comp.Input);
 106                                         goto default;
 107                                 default:
 108                                         sb.Append (c);
 109                                         break;
 110                                 }
 111                         }
 112                         if (sb.Length != 0) {
 113                                 // Ok, we have already found a text
 114                                 // part, lets save that.
 115                                 avtParts.Add (new SimpleAvtPart (sb.ToString ()));
 116                                 sb.Length = 0;
 117                         }
 118                 }
 119
 120                 public static string AttemptPreCalc (ref XslAvt avt)
 121                 {
 122                         if (avt == null) return null;
 123                         if (avt.simpleString != null) {
 124                                 string s = avt.simpleString;
 125                                 avt = null;
 126                                 return s;
 127                         }
 128                         return null;
 129                 }
 130
 131                 public string Evaluate (XslTransformProcessor p)
 132                 {
 133                         if (simpleString != null) return simpleString;
 134                         if (avtParts.Count == 1)
 135                                 return ((AvtPart) avtParts [0]).Evaluate (p);
 136
 137                         StringBuilder sb = p.GetAvtStringBuilder ();
 138
 139                         int len = avtParts.Count;
 140                         for (int i = 0; i < len; i++)
 141                                 sb.Append (((AvtPart) avtParts [i]).Evaluate (p));
 142
 143                         return p.ReleaseAvtStringBuilder ();
 144                 }
 145
 146                 // Represents part of an AVT
 147                 abstract class AvtPart {
 148                         public abstract string Evaluate (XslTransformProcessor p);
 149                 }
 150
 151                 sealed class SimpleAvtPart : AvtPart {
 152                         string val;
 153                         public SimpleAvtPart (string val)
 154                         {
 155                                 this.val = val;
 156                         }
 157
 158                         public override string Evaluate (XslTransformProcessor p)
 159                         {
 160                                 return val;
 161                         }
 162                 }
 163
 164                 sealed class XPathAvtPart : AvtPart {
 165                         XPathExpression expr;
 166
 167                         public XPathAvtPart (XPathExpression expr)
 168                         {
 169                                 this.expr = expr;
 170                         }
 171
 172                         public override string Evaluate (XslTransformProcessor p)
 173                         {
 174                                 return p.EvaluateString (expr);
 175                         }
 176                 }
 177         }
 178 }