Components/Binder/Castle.Components.Binder/DataReaderTreeBuilder.cs

   1 // Copyright 2004-2008 Castle Project - http://www.castleproject.org/
   2 //
   3 // Licensed under the Apache License, Version 2.0 (the "License");
   4 // you may not use this file except in compliance with the License.
   5 // You may obtain a copy of the License at
   6 //
   7 //     http://www.apache.org/licenses/LICENSE-2.0
   8 //
   9 // Unless required by applicable law or agreed to in writing, software
  10 // distributed under the License is distributed on an "AS IS" BASIS,
  11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 // See the License for the specific language governing permissions and
  13 // limitations under the License.
  14
  15 namespace Castle.Components.Binder
  16 {
  17         using System;
  18         using System.Collections;
  19         using System.Collections.Specialized;
  20         using System.Data;
  21
  22         /// <summary>
  23         ///
  24         /// </summary>
  25         public class DataReaderTreeBuilder
  26         {
  27                 /// <summary>
  28                 ///
  29                 /// </summary>
  30                 /// <param name="reader"></param>
  31                 /// <param name="prefix"></param>
  32                 /// <returns></returns>
  33                 public CompositeNode BuildSourceNode(IDataReader reader, String prefix)
  34                 {
  35                         CompositeNode root = new CompositeNode("root");
  36
  37                         PopulateTree(root, reader, prefix);
  38
  39                         return root;
  40                 }
  41
  42                 /// <summary>
  43                 ///
  44                 /// </summary>
  45                 /// <param name="root"></param>
  46                 /// <param name="reader"></param>
  47                 /// <param name="prefix"></param>
  48                 public void PopulateTree(CompositeNode root, IDataReader reader, String prefix)
  49                 {
  50                         string[] fields = GetFields(reader);
  51
  52                         int[] indexesToSkip = FindDuplicateFields(fields);
  53
  54                         IndexedNode indexNode = new IndexedNode(prefix);
  55
  56                         int row = 0;
  57
  58                         while(reader.Read())
  59                         {
  60                                 CompositeNode node = new CompositeNode(row.ToString());
  61
  62                                 for(int i=0; i<reader.FieldCount; i++)
  63                                 {
  64                                         // Is in the skip list?
  65                                         if (Array.IndexOf(indexesToSkip, i) >= 0) continue;
  66
  67                                         // Is null?
  68                                         if (reader.IsDBNull(i)) continue;
  69
  70                                         Type fieldType = reader.GetFieldType(i);
  71
  72                                         node.AddChildNode(new LeafNode(fieldType, fields[i], reader.GetValue(i)));
  73                                 }
  74
  75                                 indexNode.AddChildNode(node);
  76
  77                                 row++;
  78                         }
  79
  80                         root.AddChildNode(indexNode);
  81                 }
  82
  83                 private string[] GetFields(IDataReader reader)
  84                 {
  85                         String[] fields = new String[reader.FieldCount];
  86
  87                         for(int i=0; i< reader.FieldCount; i++)
  88                         {
  89                                 fields[i] = reader.GetName(i);
  90                         }
  91
  92                         return fields;
  93                 }
  94
  95                 /// <summary>
  96                 /// Check the fields for duplicates.
  97                 /// </summary>
  98                 /// <param name="fields"></param>
  99                 /// <returns></returns>
 100                 /// <remarks>
 101                 /// I have to add this check as some stored procedures
 102                 /// return duplicate columns (doh!) and this isn't good
 103                 /// for the binder.
 104                 /// </remarks>
 105                 private int[] FindDuplicateFields(string[] fields)
 106                 {
 107                         HybridDictionary dict = new HybridDictionary(fields.Length, true);
 108                         ArrayList duplicateList = new ArrayList();
 109
 110                         for(int i=0; i < fields.Length; i++)
 111                         {
 112                                 String field = fields[i];
 113
 114                                 if (dict.Contains(field))
 115                                 {
 116                                         duplicateList.Add(i);
 117                                         continue;
 118                                 }
 119
 120                                 dict.Add(field, String.Empty);
 121                         }
 122
 123                         return (int[]) duplicateList.ToArray(typeof(int));
 124                 }
 125         }
 126 }