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                                         else
 106                                                 throw new DataException (Locale.GetText ("Cannot load diffGram. Table '" + reader.LocalName + "' is missing in the destination dataset"));
 107                                 }
 108                                 else
 109                                         reader.Skip ();
 110                         }
 111
 112                         reader.ReadEndElement ();
 113                 }
 114
 115                 private void LoadBefore (XmlReader reader)
 116                 {
 117                         if (reader.IsEmptyElement) return;
 118
 119                         reader.ReadStartElement ();
 120                         reader.MoveToContent ();
 121
 122                         while (reader.NodeType != XmlNodeType.EndElement)
 123                         {
 124                                 if (reader.NodeType == XmlNodeType.Element)
 125                                 {
 126                                         DataTable t = GetTable (reader.LocalName);
 127                                         if (t != null)
 128                                                 LoadBeforeTable(t, reader);
 129                                         else
 130                                                 throw new DataException (Locale.GetText ("Cannot load diffGram. Table '" + reader.LocalName + "' is missing in the destination dataset"));
 131                                 }
 132                                 else
 133                                         reader.Skip ();
 134                         }
 135
 136                         reader.ReadEndElement ();
 137                 }
 138
 139
 140                 private void LoadErrors (XmlReader reader)
 141                 {
 142                         if (reader.IsEmptyElement) return;
 143
 144                         reader.ReadStartElement ();
 145                         reader.MoveToContent ();
 146
 147                         while (reader.NodeType != XmlNodeType.EndElement)
 148                         {
 149                                 if (reader.NodeType == XmlNodeType.Element)
 150                                 {
 151                                         DataRow Row = null;
 152
 153                                         // find the row in 'current' section
 154
 155                                         string id = reader.GetAttribute ("id", XmlConstants.DiffgrNamespace);
 156
 157                                         if (id != null)
 158                                                 Row = (DataRow) ErrorRows [id];
 159
 160                                         if (reader.IsEmptyElement) continue;
 161                                         reader.ReadStartElement ();
 162                                         while (reader.NodeType != XmlNodeType.EndElement)
 163                                         {
 164                                                 if (reader.NodeType == XmlNodeType.Element) {
 165                                                         string error = reader.GetAttribute ("Error", XmlConstants.DiffgrNamespace);
 166                                                         Row.SetColumnError (reader.LocalName, error);
 167                                                 }
 168                                                 reader.Read ();
 169                                         }
 170                                 }
 171                                 else
 172                                         reader.Skip ();
 173                         }
 174                         reader.ReadEndElement ();
 175                 }
 176
 177                 private void LoadColumns (DataTable Table, DataRow Row, XmlReader reader, DataRowVersion loadType)
 178                 {
 179                         if (reader.IsEmptyElement) return;
 180
 181                         reader.ReadStartElement ();
 182                         reader.MoveToContent ();
 183
 184                         while (reader.NodeType != XmlNodeType.EndElement)
 185                         {
 186                                 if (reader.NodeType != XmlNodeType.Element) { reader.Read (); continue; }
 187
 188                                 if (Table.Columns.Contains (reader.LocalName))
 189                                 {
 190                                         string colName = reader.LocalName;
 191                                         object data = XmlDataLoader.StringToObject (Table.Columns[colName].DataType, reader.ReadString ());
 192
 193                                         if (loadType == DataRowVersion.Current) Row [colName] = data;
 194                                         else Row.SetOriginalValue (colName, data);
 195                                         reader.Read ();
 196                                 }
 197                                 else
 198                                 {
 199                                         DataTable t = GetTable (reader.LocalName);
 200                                         if (t != null) {
 201                                                 if (loadType == DataRowVersion.Original)
 202                                                         LoadBeforeTable (t, reader);
 203                                                 else if (loadType == DataRowVersion.Current)
 204                                                         LoadCurrentTable (t, reader);
 205                                         }
 206                                 }
 207                         }
 208
 209                         reader.ReadEndElement ();
 210                 }
 211
 212                 private void LoadBeforeTable (DataTable Table, XmlReader reader)
 213                 {
 214                         string id = reader.GetAttribute ("id", XmlConstants.DiffgrNamespace);
 215                         string rowOrder = reader.GetAttribute ("rowOrder", XmlConstants.MsdataNamespace);
 216                         DataRow Row = (DataRow) DiffGrRows [id];
 217
 218                         if (Row == null)
 219                         {
 220                                 // Deleted row
 221                                 Row = Table.NewRow ();
 222                                 LoadColumns (Table, Row, reader, DataRowVersion.Current);
 223                                 Table.Rows.InsertAt (Row, int.Parse (rowOrder));
 224                                 Row.AcceptChanges ();
 225                                 Row.Delete ();
 226                         }
 227                         else
 228                         {
 229                                 LoadColumns (Table, Row, reader, DataRowVersion.Original);
 230                         }
 231                 }
 232
 233                 private void LoadCurrentTable (DataTable Table, XmlReader reader)
 234                 {
 235                         DataRowState state;
 236                         DataRow Row = Table.NewRow ();
 237
 238                         string id = reader.GetAttribute  ("id", XmlConstants.DiffgrNamespace);
 239                         string error = reader.GetAttribute ("hasErrors");
 240                         string changes = reader.GetAttribute ("hasChanges", XmlConstants.DiffgrNamespace);
 241
 242                         if (changes != null)
 243                         {
 244                                 if (string.Compare (changes, "modified", true) == 0) {
 245                                         DiffGrRows.Add (id, Row); // for later use
 246                                         state = DataRowState.Modified;
 247                                 }
 248                                 else if (string.Compare (changes, "inserted", true) == 0) {
 249                                         state = DataRowState.Added;
 250                                 }
 251                                 else
 252                                         throw new InvalidOperationException ("Invalid row change state");
 253                         }
 254                         else
 255                                 state = DataRowState.Unchanged;
 256
 257                         // If row had errors add row to hashtable for later use
 258                         if (error != null && string.Compare (error, "true", true) == 0)
 259                                 ErrorRows.Add (id, Row);
 260
 261                         LoadColumns (Table, Row, reader, DataRowVersion.Current);
 262                         Table.Rows.Add (Row);
 263
 264                         if (state != DataRowState.Added)
 265                                 Row.AcceptChanges ();
 266                 }
 267
 268                 DataTable GetTable (string name)
 269                 {
 270                         if (DSet != null)
 271                                 return DSet.Tables [name];
 272                         else if (name == table.TableName)
 273                                 return table;
 274                         else
 275                                 return null;
 276                 }
 277
 278
 279                 #endregion // Private methods
 280         }
 281 }