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

   1 /**\r
   2  * Namespace: System.Web.UI.Utils\r
   3  * Class:     DataSourceHelper\r
   4  *\r
   5  * Author:  Gaurav Vaish\r
   6  * Maintainer: gvaish@iitk.ac.in\r
   7  * Contact: <my_scripts2001@yahoo.com>, <gvaish@iitk.ac.in>\r
   8  * Status:  10%\r
   9  *\r
  10  * (C) Gaurav Vaish (2001)\r
  11  */\r
  12 \r
  13 using System;\r
  14 using System.Collections;\r
  15 using System.ComponentModel;\r
  16 \r
  17 namespace System.Web.Utils\r
  18 {\r
  19         internal class DataSourceHelper\r
  20         {\r
  21                 public static IEnumerable GetResolvedDataSource(object source, string member)\r
  22                 {\r
  23                         if(source==null)\r
  24                                 return null;\r
  25                         if(source is IListSource)\r
  26                         {\r
  27                                 IListSource ils = (IListSource)source;\r
  28                                 IList       il  = ils.GetList();\r
  29                                 if(ils.ContainsListCollection)\r
  30                                 {\r
  31                                         return il;\r
  32                                 }\r
  33                                 if(il is ITypedList)\r
  34                                 {\r
  35                                         ITypedList itl = (ITypedList)il;\r
  36                                         PropertyDescriptorCollection pdc = itl.GetItemProperties(new PropertyDescriptor[0]);\r
  37                                         PropertyDescriptor pd = null;\r
  38                                         if(pdc != null)\r
  39                                         {\r
  40                                                 if(pdc.Count > 0)\r
  41                                                 {\r
  42                                                         if(member != null)\r
  43                                                         {\r
  44                                                                 if(member.Length > 0)\r
  45                                                                 {\r
  46                                                                         pd = pdc.Find(member, true);\r
  47                                                                 } else\r
  48                                                                 {\r
  49                                                                         pd = pdc[0];\r
  50                                                                 }\r
  51                                                         }\r
  52                                                 }\r
  53                                         }\r
  54                                         if(pd!=null)\r
  55                                         {\r
  56                                                 object o = pd.GetValue(il[0]);\r
  57                                                 if(o!=null)\r
  58                                                 {\r
  59                                                         if(o is IEnumerable)\r
  60                                                                 return (IEnumerable)o;\r
  61                                                 }\r
  62                                                 throw new HttpException("ListSource Empty"); // no data in ListSource object\r
  63                                         }\r
  64                                 }\r
  65                         } else if(source is IEnumerable)\r
  66                         {\r
  67                                 return (IEnumerable)source;\r
  68                         }\r
  69                         return null;\r
  70                 }\r
  71         }\r
  72 }\r