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

   1 //
   2 // XslChoose.cs
   3 //
   4 // Authors:
   5 //      Ben Maurer (bmaurer@users.sourceforge.net)
   6 //      Atsushi Enomoto (ginga@kit.hi-ho.ne.jp)
   7 //
   8 // (C) 2003 Ben Maurer
   9 // (C) 2003 Atsushi Enomoto
  10 //
  11
  12 using System;
  13 using System.Collections;
  14 using System.Xml;
  15 using System.Xml.XPath;
  16 using System.Xml.Xsl;
  17
  18 namespace Mono.Xml.Xsl.Operations {
  19         public class XslChoose : XslCompiledElement {
  20                 XslOperation defaultChoice = null;
  21                 ArrayList conditions = new ArrayList ();
  22
  23                 public XslChoose (Compiler c) : base (c) {}
  24
  25                 protected override void Compile (Compiler c)
  26                 {
  27                         if (!c.Input.MoveToFirstChild ()) throw new Exception ("Expecting non-empty element");
  28
  29                         do {
  30                                 if (c.Input.NodeType != XPathNodeType.Element) continue;
  31                                 if (c.Input.NamespaceURI != XsltNamespace) continue;
  32
  33                                 if (defaultChoice != null)
  34                                         throw new Exception ("otherwise attribute must be last");
  35
  36                                 switch (c.Input.LocalName) {
  37                                 case "when":
  38                                         conditions.Add (new XslIf (c));
  39                                         break;
  40
  41                                 case "otherwise":
  42                                         if (c.Input.MoveToFirstChild ()) {
  43                                                 defaultChoice = c.CompileTemplateContent ();
  44                                                 c.Input.MoveToParent ();
  45                                         }
  46                                         break;
  47
  48                                 default:
  49                                         break; // TODO: forwards compat
  50                                 }
  51                         } while (c.Input.MoveToNext ());
  52
  53                         c.Input.MoveToParent ();
  54
  55                         if (conditions.Count == 0)
  56                                 throw new Exception ("Choose must have 1 or ore when elements");
  57                 }
  58
  59                 public override void Evaluate (XslTransformProcessor p)
  60                 {
  61                         foreach (XslIf test in conditions) {
  62                                 if (test.EvaluateIfTrue (p))
  63                                         return;
  64                         }
  65                         if (defaultChoice != null)
  66                                 defaultChoice.Evaluate (p);
  67                 }
  68
  69         }
  70 }