Fix the behavior or column SetName method

Author: asmirnov82

src/Microsoft.Data.Analysis/DataFrame.Join.cs

@@ -30,7 +30,7 @@ private void SetSuffixForDuplicatedColumnNames(DataFrame dataFrame, DataFrameCol
             {
                 // Pre-existing column. Change name
                 DataFrameColumn existingColumn = dataFrame.Columns[index];
-                dataFrame._columnCollection.SetColumnName(existingColumn, existingColumn.Name + leftSuffix);
+                existingColumn.SetName(existingColumn.Name + leftSuffix);
                 column.SetName(column.Name + rightSuffix);
                 index = dataFrame._columnCollection.IndexOf(column.Name);
             }

src/Microsoft.Data.Analysis/DataFrame.cs

@@ -301,7 +301,7 @@ public DataFrame AddPrefix(string prefix, bool inPlace = false)
             for (int i = 0; i < df.Columns.Count; i++)
             {
                 DataFrameColumn column = df.Columns[i];
-                df._columnCollection.SetColumnName(column, prefix + column.Name);
+                column.SetName(prefix + column.Name);
                 df.OnColumnsChanged();
             }
             return df;
@@ -316,7 +316,7 @@ public DataFrame AddSuffix(string suffix, bool inPlace = false)
             for (int i = 0; i < df.Columns.Count; i++)
             {
                 DataFrameColumn column = df.Columns[i];
-                df._columnCollection.SetColumnName(column, column.Name + suffix);
+                column.SetName(column.Name + suffix);
                 df.OnColumnsChanged();
             }
             return df;

src/Microsoft.Data.Analysis/DataFrameColumn.cs

@@ -84,6 +84,26 @@ protected set
             }
         }
 
+        // List of ColumnCollections that owns the column
+        // Current API allows column to be added into multiple dataframes, that's why the list is needed
+        private readonly List<DataFrameColumnCollection> _ownerColumnCollections = new();
+
+        internal void AddOwner(DataFrameColumnCollection columCollection)
+        {
+            if (!_ownerColumnCollections.Contains(columCollection))
+            {
+                _ownerColumnCollections.Add(columCollection);
+            }
+        }
+
+        internal void RemoveOwner(DataFrameColumnCollection columCollection)
+        {
+            if (_ownerColumnCollections.Contains(columCollection))
+            {
+                _ownerColumnCollections.Remove(columCollection);
+            }
+        }
+
         /// <summary>
         /// The number of <see langword="null" /> values in this column.
         /// </summary>
@@ -95,24 +115,30 @@ public abstract long NullCount
         private string _name;
 
         /// <summary>
-        /// The name of this column.
+        /// The column name.
         /// </summary>
         public string Name => _name;
 
         /// <summary>
-        /// Updates the name of this column.
+        /// Updates the column name.
         /// </summary>
         /// <param name="newName">The new name.</param>
-        /// <param name="dataFrame">If passed in, update the column name in <see cref="DataFrame.Columns"/></param>
-        public void SetName(string newName, DataFrame dataFrame = null)
+        public void SetName(string newName)
         {
-            if (!(dataFrame is null))
-            {
-                dataFrame.Columns.SetColumnName(this, newName);
-            }
+            foreach (var owner in _ownerColumnCollections)
+                owner.UpdateColumnNameMetadata(this, newName);
+
             _name = newName;
         }
 
+        /// <summary>
+        /// Updates the name of this column.
+        /// </summary>
+        /// <param name="newName">The new name.</param>
+        /// <param name="dataFrame">Ignored (for backward compatibility)</param>
+        [Obsolete]
+        public void SetName(string newName, DataFrame dataFrame) => SetName(newName);
+
         /// <summary>
         /// The type of data this column holds.
         /// </summary>

src/Microsoft.Data.Analysis/DataFrameColumnCollection.cs

@@ -41,11 +41,23 @@ internal IReadOnlyList<string> GetColumnNames()
             return ret;
         }
 
+        public void RenameColumn(string currentName, string newName)
+        {
+            var column = this[currentName];
+            column.SetName(newName);
+        }
+
+        [Obsolete]
         public void SetColumnName(DataFrameColumn column, string newName)
+        {
+            column.SetName(newName);
+        }
+
+        //Updates column's metadata (is used as a callback from Column class)
+        internal void UpdateColumnNameMetadata(DataFrameColumn column, string newName)
         {
             string currentName = column.Name;
             int currentIndex = _columnNameToIndexDictionary[currentName];
-            column.SetName(newName);
             _columnNames[currentIndex] = newName;
             _columnNameToIndexDictionary.Remove(currentName);
             _columnNameToIndexDictionary.Add(newName, currentIndex);
@@ -76,6 +88,9 @@ protected override void InsertItem(int columnIndex, DataFrameColumn column)
             {
                 throw new ArgumentException(string.Format(Strings.DuplicateColumnName, column.Name), nameof(column));
             }
+
+            column.AddOwner(this);
+
             RowCount = column.Length;
             _columnNames.Insert(columnIndex, column.Name);
             _columnNameToIndexDictionary[column.Name] = columnIndex;
@@ -99,10 +114,14 @@ protected override void SetItem(int columnIndex, DataFrameColumn column)
             {
                 throw new ArgumentException(string.Format(Strings.DuplicateColumnName, column.Name), nameof(column));
             }
+
             _columnNameToIndexDictionary.Remove(_columnNames[columnIndex]);
             _columnNames[columnIndex] = column.Name;
             _columnNameToIndexDictionary[column.Name] = columnIndex;
+
+            this[columnIndex].RemoveOwner(this);
             base.SetItem(columnIndex, column);
+
             ColumnsChanged?.Invoke();
         }
 
@@ -114,7 +133,10 @@ protected override void RemoveItem(int columnIndex)
                 _columnNameToIndexDictionary[_columnNames[i]]--;
             }
             _columnNames.RemoveAt(columnIndex);
+
+            this[columnIndex].RemoveOwner(this);
             base.RemoveItem(columnIndex);
+
             ColumnsChanged?.Invoke();
         }
 

test/Microsoft.Data.Analysis.Tests/DataFrameTests.cs

@@ -323,6 +323,44 @@ public void InsertAndRemoveColumnTests()
             Assert.True(ReferenceEquals(charColumn, charColumn_1));
         }
 
+        [Fact]
+        public void RenameColumnWithSetNameTests()
+        {
+            StringDataFrameColumn city = new StringDataFrameColumn("City", new string[] { "London", "Berlin" });
+            PrimitiveDataFrameColumn<int> temp = new PrimitiveDataFrameColumn<int>("Temperature", new int[] { 12, 13 });
+
+            DataFrame dataframe = new DataFrame(city, temp);
+
+            // Change the name of the column:
+            dataframe["City"].SetName("Town");
+            var renamedColumn = dataframe["Town"];
+
+            Assert.Throws<ArgumentException>(() => dataframe["City"]);
+
+            Assert.NotNull(renamedColumn);
+            Assert.Equal("Town", renamedColumn.Name);
+            Assert.True(ReferenceEquals(city, renamedColumn));
+        }
+
+        [Fact]
+        public void RenameColumnWithRenameColumnTests()
+        {
+            StringDataFrameColumn city = new StringDataFrameColumn("City", new string[] { "London", "Berlin" });
+            PrimitiveDataFrameColumn<int> temp = new PrimitiveDataFrameColumn<int>("Temperature", new int[] { 12, 13 });
+
+            DataFrame dataframe = new DataFrame(city, temp);
+
+            // Change the name of the column:
+            dataframe.Columns.RenameColumn("City", "Town");
+            var renamedColumn = dataframe["Town"];
+
+            Assert.Throws<ArgumentException>(() => dataframe["City"]);
+
+            Assert.NotNull(renamedColumn);
+            Assert.Equal("Town", renamedColumn.Name);
+            Assert.True(ReferenceEquals(city, renamedColumn));
+        }
+
         [Fact]
         public void TestBinaryOperations()
         {