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

   1 //
   2 // XslAttribute.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 using System.IO;
  18
  19 using QName = System.Xml.XmlQualifiedName;
  20
  21 namespace Mono.Xml.Xsl.Operations {
  22         public class XslAttribute : XslCompiledElement {
  23                 XslAvt name, ns;
  24                 string calcName, calcNs, calcPrefix;
  25                 XmlNamespaceManager nsm;
  26
  27                 XslOperation value;
  28                 XPathNavigator nav;
  29
  30                 public XslAttribute (Compiler c) : base (c) {}
  31
  32                 protected override void Compile (Compiler c)
  33                 {
  34                         nav = c.Input.Clone ();
  35
  36                         name = c.ParseAvtAttribute ("name");
  37                         ns = c.ParseAvtAttribute ("namespace");
  38
  39                         calcName = XslAvt.AttemptPreCalc (ref name);
  40
  41                         if (calcName != null && ns == null) {
  42                                 int colonAt = calcName.IndexOf (':');
  43                                 calcPrefix = colonAt < 0 ? String.Empty : calcName.Substring (0, colonAt);
  44                                 calcName = colonAt < 0 ? calcName : calcName.Substring (colonAt + 1, calcName.Length - colonAt - 1);
  45                                 calcNs = nav.GetNamespace (calcPrefix);
  46                         } else if (ns != null)
  47                                 calcNs = XslAvt.AttemptPreCalc (ref ns);
  48
  49                         if (ns == null && calcNs == null)
  50                                 nsm = c.GetNsm ();
  51
  52                         if (c.Input.MoveToFirstChild ()) {
  53                                 value = c.CompileTemplateContent ();
  54                                 c.Input.MoveToParent ();
  55                         }
  56
  57                 }
  58
  59                 public override void Evaluate (XslTransformProcessor p)
  60                 {
  61                         string nm, nmsp, localName, prefix;
  62
  63                         nm = calcName != null ? calcName : name.Evaluate (p);
  64                         nmsp = calcNs != null ? calcNs : ns != null ? ns.Evaluate (p) : String.Empty;
  65                         prefix = calcPrefix != null ? calcPrefix : String.Empty;
  66
  67                         if (nm == "xmlns")
  68                                 // It is an error. We must recover by not emmiting any attributes
  69                                 // (unless we throw an exception).
  70                                 return;
  71
  72                         int colonAt = nm.IndexOf (':');
  73                         // local attribute
  74                         prefix = colonAt < 0 ? String.Empty : nm.Substring (0, colonAt);
  75                         nm = colonAt < 0 ? nm : nm.Substring (colonAt + 1, nm.Length - colonAt - 1);
  76                         if (colonAt > 0) {
  77                                 // global attribute
  78                                 if (nmsp == null) {
  79                                         QName q = XslNameUtil.FromString (nm, nsm);
  80                                         nm = q.Name;
  81                                         nmsp = q.Namespace;
  82                                 } else
  83                                         nm = XslNameUtil.LocalNameOf (nm);
  84                         }
  85
  86                         if (nmsp != String.Empty && prefix == String.Empty) {
  87                                 if (nav.MoveToFirstNamespace (XPathNamespaceScope.ExcludeXml)) {
  88                                         do {
  89                                                 if (nav.Value == nmsp) {
  90                                                         prefix = nav.Name;
  91                                                         break;
  92                                                 }
  93                                         } while (nav.MoveToNextNamespace (XPathNamespaceScope.ExcludeXml));
  94                                         nav.MoveToParent ();
  95                                 }
  96                         }
  97
  98                         if (prefix == "xmlns")
  99                                 prefix = String.Empty;  // Should not be allowed.
 100
 101                         XmlConvert.VerifyName (nm);
 102
 103                         if (value == null)
 104                                 p.Out.WriteAttributeString(prefix, nm, nmsp, "");
 105                         else {
 106                                 StringWriter sw = new StringWriter ();
 107                                 Outputter outputter = new TextOutputter (sw, true);
 108                                 p.PushOutput (outputter);
 109                                 value.Evaluate (p);
 110                                 p.PopOutput ();
 111                                 outputter.Done ();
 112                                 p.Out.WriteAttributeString (prefix, nm, nmsp, sw.ToString ());
 113                         }
 114                 }
 115         }
 116 }