mcs/class/System.Data/System.Data/XmlDiffLoader.cs

   1 //
   2 // mcs/class/System.Data/System.Data/XmlDiffLoader.cs
   3 //
   4 // Purpose: Loads XmlDiffGrams to DataSet
   5 //
   6 // class: XmlDiffLoader
   7 // assembly: System.Data.dll
   8 // namespace: System.Data
   9 //
  10 // Author:
  11 //     Ville Palo <vi64pa@koti.soon.fi>
  12 //     Lluis Sanchez Gual (lluis@ximian.com)
  13 //
  14 // (c)copyright 2003 Ville Palo
  15 //
  16 using System;
  17 using System.Data;
  18 using System.Xml;
  19 using System.Xml.XPath;
  20 using System.Collections;
  21 using System.Globalization;
  22
  23 namespace System.Data {
  24
  25         internal class XmlDiffLoader
  26         {
  27
  28                 #region Fields
  29                 private DataSet DSet;
  30                 private DataTable table;
  31                 private Hashtable DiffGrRows = new Hashtable ();
  32                 private Hashtable ErrorRows = new Hashtable ();
  33
  34                 #endregion // Fields
  35
  36                 #region ctors
  37
  38                 public XmlDiffLoader (DataSet DSet)
  39                 {
  40                         this.DSet = DSet;
  41                 }
  42
  43                 public XmlDiffLoader (DataTable table)
  44                 {
  45                         this.table = table;
  46                 }
  47
  48                 #endregion //ctors
  49
  50                 #region Public methods
  51
  52                 public void Load (XmlReader reader)
  53                 {
  54                         bool origEnforceConstraint = false;
  55                         if (DSet != null) {
  56                                 origEnforceConstraint = DSet.EnforceConstraints;
  57                                 DSet.EnforceConstraints = false;
  58                         }
  59
  60                         reader.MoveToContent ();
  61                         if (reader.IsEmptyElement) return;
  62
  63                         reader.ReadStartElement ("diffgram", XmlConstants.DiffgrNamespace);
  64                         reader.MoveToContent ();
  65
  66                         while (reader.NodeType != XmlNodeType.EndElement)
  67                         {
  68                                 if (reader.NodeType == XmlNodeType.Element)
  69                                 {
  70                                         if (reader.LocalName == "before" && reader.NamespaceURI == XmlConstants.DiffgrNamespace)
  71                                                 LoadBefore (reader);
  72                                         else if (reader.LocalName == "errors" && reader.NamespaceURI == XmlConstants.DiffgrNamespace)
  73                                                 LoadErrors (reader);
  74                                         else
  75                                                 LoadCurrent (reader);
  76                                 }
  77                                 else
  78                                         reader.Skip ();
  79                         }
  80
  81                         reader.ReadEndElement ();
  82
  83                         if (DSet != null)
  84                                 DSet.EnforceConstraints = origEnforceConstraint;
  85                 }
  86
  87                 #endregion // Public methods
  88
  89                 #region Private methods
  90
  91                 private void LoadCurrent (XmlReader reader)
  92                 {
  93                         if (reader.IsEmptyElement) return;
  94
  95                         reader.ReadStartElement ();             // Dataset root
  96                         reader.MoveToContent ();
  97
  98                         while (reader.NodeType != XmlNodeType.EndElement)
  99                         {
 100                                 if (reader.NodeType == XmlNodeType.Element)
 101                                 {
 102                                         DataTable t = GetTable (reader.LocalName);
 103                                         if (t != null)
 104                                                 LoadCurrentTable (t, reader);
 105 #if true
 106                                         else
 107                                                 reader.Skip ();
 108 #else
 109                                         else
 110                                                 throw new DataException (Locale.GetText ("Cannot load diffGram. Table '" + reader.LocalName + "' is missing in the destination dataset"));
 111 #endif
 112                                 }
 113                                 else
 114                                         reader.Skip ();
 115                         }
 116
 117                         reader.ReadEndElement ();
 118                 }
 119
 120                 private void LoadBefore (XmlReader reader)
 121                 {
 122                         if (reader.IsEmptyElement) return;
 123
 124                         reader.ReadStartElement ();
 125                         reader.MoveToContent ();
 126
 127                         while (reader.NodeType != XmlNodeType.EndElement)
 128                         {
 129                                 if (reader.NodeType == XmlNodeType.Element)
 130                                 {
 131                                         DataTable t = GetTable (reader.LocalName);
 132                                         if (t != null)
 133                                                 LoadBeforeTable(t, reader);
 134                                         else
 135                                                 throw new DataException (Locale.GetText ("Cannot load diffGram. Table '" + reader.LocalName + "' is missing in the destination dataset"));
 136                                 }
 137                                 else
 138                                         reader.Skip ();
 139                         }
 140
 141                         reader.ReadEndElement ();
 142                 }
 143
 144
 145                 private void LoadErrors (XmlReader reader)
 146                 {
 147                         if (reader.IsEmptyElement) return;
 148
 149                         reader.ReadStartElement ();
 150                         reader.MoveToContent ();
 151
 152                         while (reader.NodeType != XmlNodeType.EndElement)
 153                         {
 154                                 if (reader.NodeType == XmlNodeType.Element)
 155                                 {
 156                                         DataRow Row = null;
 157
 158                                         // find the row in 'current' section
 159
 160                                         string id = reader.GetAttribute ("id", XmlConstants.DiffgrNamespace);
 161
 162                                         if (id != null)
 163                                                 Row = (DataRow) ErrorRows [id];
 164
 165                                         if (reader.IsEmptyElement) continue;
 166                                         reader.ReadStartElement ();
 167                                         while (reader.NodeType != XmlNodeType.EndElement)
 168                                         {
 169                                                 if (reader.NodeType == XmlNodeType.Element) {
 170                                                         string error = reader.GetAttribute ("Error", XmlConstants.DiffgrNamespace);
 171                                                         Row.SetColumnError (reader.LocalName, error);
 172                                                 }
 173                                                 reader.Read ();
 174                                         }
 175                                 }
 176                                 else
 177                                         reader.Skip ();
 178                         }
 179                         reader.ReadEndElement ();
 180                 }
 181
 182                 private void LoadColumns (DataTable Table, DataRow Row, XmlReader reader, DataRowVersion loadType)
 183                 {
 184                         if (reader.IsEmptyElement) return;
 185
 186                         reader.ReadStartElement ();
 187                         reader.MoveToContent ();
 188
 189                         while (reader.NodeType != XmlNodeType.EndElement)
 190                         {
 191                                 if (reader.NodeType != XmlNodeType.Element) { reader.Read (); continue; }
 192
 193                                 if (Table.Columns.Contains (reader.LocalName))
 194                                 {
 195                                         string colName = reader.LocalName;
 196                                         object data = XmlDataLoader.StringToObject (Table.Columns[colName].DataType, reader.ReadString ());
 197
 198                                         if (loadType == DataRowVersion.Current) Row [colName] = data;
 199                                         else Row.SetOriginalValue (colName, data);
 200                                         reader.Read ();
 201                                 }
 202                                 else
 203                                 {
 204                                         DataTable t = GetTable (reader.LocalName);
 205                                         if (t != null) {
 206                                                 if (loadType == DataRowVersion.Original)
 207                                                         LoadBeforeTable (t, reader);
 208                                                 else if (loadType == DataRowVersion.Current)
 209                                                         LoadCurrentTable (t, reader);
 210                                         }
 211                                 }
 212                         }
 213
 214                         reader.ReadEndElement ();
 215                 }
 216
 217                 private void LoadBeforeTable (DataTable Table, XmlReader reader)
 218                 {
 219                         string id = reader.GetAttribute ("id", XmlConstants.DiffgrNamespace);
 220                         string rowOrder = reader.GetAttribute ("rowOrder", XmlConstants.MsdataNamespace);
 221                         DataRow Row = (DataRow) DiffGrRows [id];
 222
 223                         if (Row == null)
 224                         {
 225                                 // Deleted row
 226                                 Row = Table.NewRow ();
 227                                 LoadColumns (Table, Row, reader, DataRowVersion.Current);
 228                                 Table.Rows.InsertAt (Row, int.Parse (rowOrder));
 229                                 Row.AcceptChanges ();
 230                                 Row.Delete ();
 231                         }
 232                         else
 233                         {
 234                                 LoadColumns (Table, Row, reader, DataRowVersion.Original);
 235                         }
 236                 }
 237
 238                 private void LoadCurrentTable (DataTable Table, XmlReader reader)
 239                 {
 240                         DataRowState state;
 241                         DataRow Row = Table.NewRow ();
 242
 243                         string id = reader.GetAttribute  ("id", XmlConstants.DiffgrNamespace);
 244                         string error = reader.GetAttribute ("hasErrors");
 245                         string changes = reader.GetAttribute ("hasChanges", XmlConstants.DiffgrNamespace);
 246
 247                         if (changes != null)
 248                         {
 249                                 if (string.Compare (changes, "modified", true) == 0) {
 250                                         DiffGrRows.Add (id, Row); // for later use
 251                                         state = DataRowState.Modified;
 252                                 }
 253                                 else if (string.Compare (changes, "inserted", true) == 0) {
 254                                         state = DataRowState.Added;
 255                                 }
 256                                 else
 257                                         throw new InvalidOperationException ("Invalid row change state");
 258                         }
 259                         else
 260                                 state = DataRowState.Unchanged;
 261
 262                         // If row had errors add row to hashtable for later use
 263                         if (error != null && string.Compare (error, "true", true) == 0)
 264                                 ErrorRows.Add (id, Row);
 265
 266                         LoadColumns (Table, Row, reader, DataRowVersion.Current);
 267                         Table.Rows.Add (Row);
 268
 269                         if (state != DataRowState.Added)
 270                                 Row.AcceptChanges ();
 271                 }
 272
 273                 DataTable GetTable (string name)
 274                 {
 275                         if (DSet != null)
 276                                 return DSet.Tables [name];
 277                         else if (name == table.TableName)
 278                                 return table;
 279                         else
 280                                 return null;
 281                 }
 282
 283
 284                 #endregion // Private methods
 285         }
 286 }