2004-03-10 Umadevi S (sumadevi@novell.com)
[mono.git] / mcs / class / System.Data / System.Data / DataTableCollection.cs
index 46c9baf7eec5f9eb2b7d90d8e256cf40d4128ff2..f4fbf6a0901df0efcfa10ce7448bcb9adac75664 100644 (file)
 using System;
 using System.Collections;
 using System.ComponentModel;
+using System.Globalization;
 
 namespace System.Data {
        /// <summary>
        /// Represents the collection of tables for the DataSet.
        /// </summary>
+       [Editor]
        [DefaultEvent ("CollectionChanged")]
        [ListBindable (false)]
        [Serializable]
        public class DataTableCollection : InternalDataCollectionBase
        {
                DataSet dataSet;
-               const string defaultTableName = "Table1";
                
                #region Constructors 
 
@@ -43,14 +44,17 @@ namespace System.Data {
 
                public DataTable this[string name] {
                        get { 
-                               foreach (DataTable dt in list) {
-                                       if (dt.TableName == name)
-                                               return dt;
-                               }
-                               
-                               return null;
-                       }                       
+                               int index = IndexOf (name, true);
+                               return index < 0 ? null : (DataTable) list[index];
+                       }
+               }
+
+#if NET_1_2
+               [MonoTODO]
+               public DataTable this [string name, string tbNamespace] {
+                       get { throw new NotImplementedException (); }
                }
+#endif
 
                protected override ArrayList List {
                        get { return list; }
@@ -62,11 +66,38 @@ namespace System.Data {
 
                public virtual DataTable Add () 
                {
-                       return this.Add (defaultTableName);
+                       DataTable Table = new DataTable ();
+                       Add (Table);
+                       return Table;
                }
 
                public virtual void Add (DataTable table) 
                {
+                       
+                       // check if the reference is a null reference
+                       if(table == null)
+                               throw new ArgumentNullException("table");
+            
+                       // check if the list already contains this tabe.
+                       if(list.Contains(table))
+                               throw new ArgumentException("DataTable already belongs to this DataSet.");
+            
+                       // if the table name is null or empty string.
+                       // give her a name. 
+                       if (table.TableName == null || table.TableName == string.Empty)
+                               NameTable (table);
+                   
+                       // check if the collection has a table with the same name.
+                       int tmp = IndexOf(table.TableName);
+                       // if we found a table with same name we have to check
+                       // that it is the same case.
+                       // indexof can return a table with different case letters.
+                       if (tmp != -1)
+                       {
+                               if(table.TableName == this[tmp].TableName)
+                                       throw new DuplicateNameException("A DataTable named '" + table.TableName + "' already belongs to this DataSet.");
+                       }
+       
                        list.Add (table);
                        table.dataSet = dataSet;
                        OnCollectionChanged (new CollectionChangeEventArgs (CollectionChangeAction.Add, table));
@@ -79,6 +110,15 @@ namespace System.Data {
                        return table;
                }
 
+#if NET_1_2
+               public virtual DataTable Add (string name, string tbNamespace)
+               {
+                       DataTable table = new DataTable (name, tbNamespace);
+                       this.Add (table);
+                       return table;
+               }
+#endif
+
                public void AddRange (DataTable[] tables) 
                {
                        foreach (DataTable table in tables)
@@ -88,7 +128,7 @@ namespace System.Data {
                [MonoTODO]
                public bool CanRemove (DataTable table) 
                {
-                       throw new NotImplementedException ();
+                       return CanRemove(table, false);
                }
 
                public void Clear () 
@@ -98,12 +138,7 @@ namespace System.Data {
 
                public bool Contains (string name) 
                {
-                       foreach (DataTable dt in list) {
-                               if (dt.TableName == name)
-                                       return true;
-                       }
-
-                       return false;
+                       return (-1 != IndexOf (name, false));
                }
 
                public virtual int IndexOf (DataTable table) 
@@ -113,23 +148,27 @@ namespace System.Data {
 
                public virtual int IndexOf (string name) 
                {
-                       return list.IndexOf (this [name]);
+                       return IndexOf (name, false);
                }
 
                public void Remove (DataTable table) 
                {
-                       this.Remove (table.TableName);
+                       CanRemove(table, true);
+                       list.Remove(table);
                        OnCollectionChanged (new CollectionChangeEventArgs (CollectionChangeAction.Remove, table));
                }
 
                public void Remove (string name) 
                {
-                       list.Remove (this [name]);
+                       Remove (this [name]);
                }
 
                public void RemoveAt (int index) 
                {
+                       DataTable t = this[index];
+                       CanRemove(t, true);
                        list.RemoveAt (index);
+                       OnCollectionChanged (new CollectionChangeEventArgs (CollectionChangeAction.Remove, t));
                }
 
                #endregion
@@ -150,6 +189,102 @@ namespace System.Data {
 
                #endregion
 
+               #region Private methods
+
+               private int IndexOf (string name, bool error)
+               {
+                       int count = 0, match = -1;
+                       for (int i = 0; i < list.Count; i++)
+                       {
+                               String name2 = ((DataTable) list[i]).TableName;
+                               if (String.Compare (name, name2, true) == 0)
+                               {
+                                       if (String.Compare (name, name2, false) == 0)
+                                               return i;
+                                       match = i;
+                                       count++;
+                               }
+                       }
+                       if (count == 1)
+                               return match;
+                       if (count > 1 && error)
+                               throw new ArgumentException ("There is no match for the name in the same case and there are multiple matches in different case.");
+                       return -1;
+               }
+
+               /// <summary>
+               /// gives name to Table (Table1, Table2, Table3,...)
+               /// </summary>
+               private void NameTable (DataTable Table)
+               {
+                       string Name = "Table";
+                       int i = 1;
+                       while (Contains (Name + i))
+                               i++;
+
+                       Table.TableName = Name + i;                            
+               }
+               
+               // check if a table can be removed from this collectiuon.
+               // if the table can not be remved act according to throwException parameter.
+               // if it is true throws an Exception, else return false.
+               private bool CanRemove(DataTable table, bool throwException)
+               {
+                       // check if table is null reference
+                       if (table == null)
+                       {
+                               if(throwException)
+                                       throw new ArgumentNullException("table");
+                               return false;
+                       }
+                       
+                       // check if the table has the same DataSet as this collection.
+                       if(table.DataSet != this.dataSet)
+                       {
+                               if(throwException)
+                                       throw new ArgumentException("Table " + table.TableName + " does not belong to this DataSet.");
+                               return false;
+                       }
+                       
+                       // check the table has a relation attached to it.
+                       if (table.ParentRelations.Count > 0 || table.ChildRelations.Count > 0)
+                       {
+                               if(throwException)
+                                       throw new ArgumentException("Cannot remove a table that has existing relations. Remove relations first.");
+                               return false;
+                       }
+                       
+
+                       // now we check if any ForeignKeyConstraint is referncing 'table'.
+                       IEnumerator tableEnumerator = this.dataSet.Tables.GetEnumerator();
+                       
+                       // loop on all tables in dataset
+                       while (tableEnumerator.MoveNext())
+                       {
+                               IEnumerator constraintEnumerator = ((DataTable) tableEnumerator.Current).Constraints.GetEnumerator();
+                               // loop on all constrains in the current table
+                               while (constraintEnumerator.MoveNext())
+                               {
+                                       Object o = constraintEnumerator.Current;
+                                       // we only check ForeignKeyConstraint
+                                       if (o is ForeignKeyConstraint)
+                                       {
+                                               ForeignKeyConstraint fc = (ForeignKeyConstraint) o;
+                                               if(fc.Table == table || fc.RelatedTable == table)
+                                               {
+                                                       if(throwException)
+                                                               throw new ArgumentException("Cannot remove table " + table.TableName + ", because it referenced in ForeignKeyConstraint " + fc.ConstraintName + ". Remove the constraint first.");
+                                                       return false;
+                                               }
+                                       }
+                               }
+                       }
+
+                       return true;
+               }
+
+               #endregion // Private methods
+
                #region Events
 
                [ResDescriptionAttribute ("Occurs whenever this collection's membership changes.")]