mcs/class/System.Web/System.Web.Util/DataSourceHelper.cs

   1
   2 //
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   4 // a copy of this software and associated documentation files (the
   5 // "Software"), to deal in the Software without restriction, including
   6 // without limitation the rights to use, copy, modify, merge, publish,
   7 // distribute, sublicense, and/or sell copies of the Software, and to
   8 // permit persons to whom the Software is furnished to do so, subject to
   9 // the following conditions:
  10 //
  11 // The above copyright notice and this permission notice shall be
  12 // included in all copies or substantial portions of the Software.
  13 //
  14 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  15 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  16 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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  20 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  21 //
  22 /**
  23  * Namespace: System.Web.UI.Util
  24  * Class:     DataSourceHelper
  25  *
  26  * Author:  Gaurav Vaish
  27  * Maintainer: gvaish@iitk.ac.in
  28  * Contact: <my_scripts2001@yahoo.com>, <gvaish@iitk.ac.in>
  29  * Status:  10%
  30  *
  31  * (C) Gaurav Vaish (2001)
  32  */
  33
  34 using System;
  35 using System.Collections;
  36 using System.ComponentModel;
  37
  38 namespace System.Web.Util
  39 {
  40         internal class DataSourceHelper
  41         {
  42                 public static IEnumerable GetResolvedDataSource(object source, string member)
  43                 {
  44                         if(source != null && source is IListSource)
  45                         {
  46                                 IListSource src = (IListSource)source;
  47                                 IList list = src.GetList();
  48                                 if(!src.ContainsListCollection)
  49                                 {
  50                                         return list;
  51                                 }
  52                                 if(list != null && list is ITypedList)
  53                                 {
  54                                         ITypedList tlist = (ITypedList)list;
  55                                         PropertyDescriptorCollection pdc = tlist.GetItemProperties(new PropertyDescriptor[0]);
  56                                         if(pdc != null && pdc.Count > 0)
  57                                         {
  58                                                 PropertyDescriptor pd = null;
  59                                                 if(member != null && member.Length > 0)
  60                                                 {
  61                                                         pd = pdc.Find(member, true);
  62                                                 } else
  63                                                 {
  64                                                         pd = pdc[0];
  65                                                 }
  66                                                 if(pd != null)
  67                                                 {
  68                                                         object rv = pd.GetValue(list[0]);
  69                                                         if(rv != null && rv is IEnumerable)
  70                                                         {
  71                                                                 return (IEnumerable)rv;
  72                                                         }
  73                                                 }
  74                                                 throw new HttpException(
  75                                                       HttpRuntime.FormatResourceString("ListSource_Missing_DataMember", member));
  76                                         }
  77                                         throw new HttpException(
  78                                               HttpRuntime.FormatResourceString("ListSource_Without_DataMembers"));
  79                                 }
  80                         }
  81                         if(source is IEnumerable)
  82                         {
  83                                 return (IEnumerable)source;
  84                         }
  85                         return null;
  86                 }
  87         }
  88 }