mcs/class/referencesource/System.Xml/System/Xml/XmlResolver.cs

   1 //------------------------------------------------------------------------------
   2 // <copyright file="XmlResolver.cs" company="Microsoft">
   3 //     Copyright (c) Microsoft Corporation.  All rights reserved.
   4 // </copyright>
   5 // <owner current="true" primary="true">Microsoft</owner>
   6 //------------------------------------------------------------------------------
   7
   8 namespace System.Xml
   9 {
  10     using System;
  11     using System.IO;
  12     using System.Text;
  13     using System.Security;
  14     using System.Security.Permissions;
  15 #if !SILVERLIGHT
  16     using System.Net;
  17     using System.Threading.Tasks;
  18 #endif
  19     using System.Runtime.Versioning;
  20
  21     /// <include file='doc\XmlResolver.uex' path='docs/doc[@for="XmlResolver"]/*' />
  22     /// <devdoc>
  23     ///    <para>Resolves external XML resources named by a Uniform
  24     ///       Resource Identifier (URI). This class is <see langword='abstract'/>
  25     ///       .</para>
  26     /// </devdoc>
  27     public abstract partial class XmlResolver {
  28         /// <include file='doc\XmlResolver.uex' path='docs/doc[@for="XmlResolver.GetEntity1"]/*' />
  29         /// <devdoc>
  30         ///    <para>Maps a
  31         ///       URI to an Object containing the actual resource.</para>
  32         /// </devdoc>
  33
  34         public abstract Object GetEntity(Uri absoluteUri,
  35                                          string role,
  36                                          Type ofObjectToReturn);
  37
  38
  39
  40         /// <include file='doc\XmlResolver.uex' path='docs/doc[@for="XmlResolver.ResolveUri"]/*' />
  41         /// <devdoc>
  42         ///    <para>[To be supplied.]</para>
  43         /// </devdoc>
  44 #if !SILVERLIGHT
  45         [ResourceExposure(ResourceScope.Machine)]
  46         [ResourceConsumption(ResourceScope.Machine)]
  47 #endif
  48         public virtual Uri ResolveUri(Uri baseUri, string relativeUri) {
  49             if ( baseUri == null || ( !baseUri.IsAbsoluteUri && baseUri.OriginalString.Length == 0 ) ) {
  50                 Uri uri = new Uri( relativeUri, UriKind.RelativeOrAbsolute );
  51 #if !SILVERLIGHT // Path.GetFullPath is SecurityCritical
  52                 if ( !uri.IsAbsoluteUri && uri.OriginalString.Length > 0 ) {
  53                     uri = new Uri( Path.GetFullPath( relativeUri ) );
  54                 }
  55 #endif
  56                 return uri;
  57             }
  58             else {
  59                 if (relativeUri == null || relativeUri.Length == 0) {
  60                     return baseUri;
  61                 }
  62                 // relative base Uri
  63                 if ( !baseUri.IsAbsoluteUri ) {
  64 #if SILVERLIGHT
  65                     // create temporary base for the relative URIs
  66                     Uri tmpBaseUri = new Uri("tmp:///");
  67
  68                     // create absolute base URI with the temporary base
  69                     Uri absBaseUri = new Uri(tmpBaseUri, baseUri.OriginalString);
  70
  71                     // resolve the relative Uri into a new absolute URI
  72                     Uri resolvedAbsUri = new Uri(absBaseUri, relativeUri);
  73
  74                     // make it relative by removing temporary base
  75                     Uri resolvedRelUri = tmpBaseUri.MakeRelativeUri(resolvedAbsUri);
  76
  77                     return resolvedRelUri;
  78 #else
  79                     throw new NotSupportedException(Res.GetString(Res.Xml_RelativeUriNotSupported));
  80 #endif
  81                 }
  82                 return new Uri( baseUri, relativeUri );
  83             }
  84         }
  85
  86 #if !SILVERLIGHT
  87         //UE attension
  88         /// <include file='doc\XmlResolver.uex' path='docs/doc[@for="XmlResolver.Credentials"]/*' />
  89         /// <devdoc>
  90         ///    <para>[To be supplied.]</para>
  91         /// </devdoc>
  92         public virtual ICredentials Credentials {
  93             set { }
  94         }
  95 #endif
  96
  97         public virtual bool SupportsType(Uri absoluteUri, Type type) {
  98             if (absoluteUri == null) {
  99                 throw new ArgumentNullException("absoluteUri");
 100             }
 101             if (type == null || type == typeof(Stream)) {
 102                 return true;
 103             }
 104             return false;
 105         }
 106     }
 107 }