mcs/class/System.XML/Mono.Xml.XPath/LocationPathPattern.cs

   1 //
   2 // Mono.Xml.XPath.LocationPathPattern
   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.Xml;
  35 using System.Xml.Schema;
  36 using System.Xml.XPath;
  37 using System.Xml.Xsl;
  38
  39 namespace Mono.Xml.XPath {
  40         internal class LocationPathPattern : Pattern {
  41
  42                 LocationPathPattern patternPrevious;
  43                 bool isAncestor;
  44                 NodeTest nodeTest;
  45                 ExprFilter filter;
  46                 XPathNavigator previousNavigator;
  47
  48                 public LocationPathPattern (NodeTest nodeTest)
  49                 {
  50                         this.nodeTest = nodeTest;
  51                 }
  52
  53                 public LocationPathPattern (ExprFilter filter)
  54                 {
  55                         this.filter = filter;
  56
  57                         while (! (filter.expr is NodeTest))
  58                                 filter = (ExprFilter)filter.expr;
  59
  60                         this.nodeTest = (NodeTest)filter.expr;
  61                 }
  62
  63                 internal void SetPreviousPattern (Pattern prev, bool isAncestor)
  64                 {
  65                         LocationPathPattern toSet = LastPathPattern;
  66                         toSet.patternPrevious = (LocationPathPattern)prev;
  67                         toSet.isAncestor = isAncestor;
  68                 }
  69
  70                 public override double DefaultPriority {
  71                         get {
  72                                 if (patternPrevious == null && filter == null) {
  73                                         NodeNameTest t = nodeTest as NodeNameTest;
  74                                         if (t != null) {
  75                                                 if (t.Name.Name == "*")
  76                                                         return -.25;
  77                                                 return 0;
  78                                         }
  79
  80                                         return -.5;
  81                                 }
  82                                 return .5;
  83                         }
  84                 }
  85
  86                 public override bool Matches (XPathNavigator node, XsltContext ctx)
  87                 {
  88                         if (! nodeTest.Match (ctx, node))
  89                                 return false;
  90
  91                         if (nodeTest is NodeTypeTest) {
  92                                 // node () is different in xslt patterns
  93                                 if (((NodeTypeTest)nodeTest).type == XPathNodeType.All &&
  94                                         (node.NodeType == XPathNodeType.Root ||
  95                                         node.NodeType == XPathNodeType.Attribute)
  96                                 )
  97                                 return false;
  98                         }
  99
 100                         if (filter == null && patternPrevious == null)
 101                                 return true;
 102
 103                         if (patternPrevious != null) {
 104                                 if (!isAncestor) {
 105                                         XPathNavigator parent = node.Clone ();
 106                                         parent.MoveToParent ();
 107                                         if (!patternPrevious.Matches (parent, ctx))
 108                                                 return false;
 109                                 } else {
 110                                         XPathNavigator anc = node.Clone ();
 111                                         while (true) {
 112                                                 if (!anc.MoveToParent ())
 113                                                         return false;
 114
 115                                                 if (patternPrevious.Matches (anc, ctx))
 116                                                         break;
 117                                         }
 118                                 }
 119                         }
 120
 121
 122                         if (filter == null)
 123                                 return true;
 124
 125                         // Optimization for non-positional predicate
 126                         if (!filter.IsPositional && !(filter.expr is ExprFilter)) {
 127                                 return filter.pred.EvaluateBoolean (new NullIterator (node, ctx));
 128                         }
 129
 130                         XPathNavigator p = null;
 131                         if (previousNavigator == node) {
 132                                 p = previousNavigator;
 133                                 p.MoveTo (node);
 134                         } else {
 135                                 p = node.Clone ();
 136                                 previousNavigator = p;
 137                         }
 138                         p.MoveToParent ();
 139
 140                         BaseIterator matches = filter.EvaluateNodeSet (new NullIterator (p, ctx));
 141
 142                         while (matches.MoveNext ()) {
 143                                 if (node.IsSamePosition (matches.Current))
 144                                         return true;
 145                         }
 146
 147                         return false;
 148                 }
 149
 150                 public override string ToString ()
 151                 {
 152                         string ret = "";
 153                         if (patternPrevious != null) ret = patternPrevious.ToString () + (isAncestor ? "//" : "/");
 154                         if (filter != null) ret += filter.ToString ();
 155                         else ret += nodeTest.ToString ();
 156
 157                         return ret;
 158                 }
 159
 160                 public LocationPathPattern LastPathPattern {
 161                         get {
 162                                 LocationPathPattern ret = this;
 163
 164                                 while (ret.patternPrevious != null)
 165                                         ret = ret.patternPrevious;
 166
 167                                 return ret;
 168                         }
 169                 }
 170         }
 171 }