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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
using System.ComponentModel;
using System.Diagnostics.CodeAnalysis;
namespace System.Data
{
public class DataRowView : ICustomTypeDescriptor, IEditableObject, IDataErrorInfo, INotifyPropertyChanged
{
private readonly DataView _dataView;
private readonly DataRow _row;
private bool _delayBeginEdit;
private static readonly PropertyDescriptorCollection s_zeroPropertyDescriptorCollection = new PropertyDescriptorCollection(null);
internal DataRowView(DataView dataView, DataRow row)
{
_dataView = dataView;
_row = row;
}
/// <remarks>
/// Checks for same reference instead of equivalent <see cref="DataView"/> or <see cref="Row"/>.
///
/// Necessary for ListChanged event handlers to use data structures that use the default to
/// <see cref="object.Equals(object)"/> instead of <see cref="object.ReferenceEquals"/>
/// to understand if they need to add a <see cref="PropertyChanged"/> event handler.
/// </remarks>
/// <returns><see cref="object.ReferenceEquals"/></returns>
public override bool Equals(object? other) => ReferenceEquals(this, other);
/// <returns>Hashcode of <see cref="Row"/></returns>
public override int GetHashCode()
{
// Everett compatibility, must return hashcode for DataRow
// this does prevent using this object in collections like Hashtable
// which use the hashcode as an immutable value to identify this object
// user could/should have used the DataRow property instead of the hashcode
return Row.GetHashCode();
}
public DataView DataView => _dataView;
internal int ObjectID => _row._objectID;
/// <summary>Gets or sets a value in specified column.</summary>
/// <param name="ndx">Specified column index.</param>
/// <remarks>Uses either <see cref="DataRowVersion.Default"/> or <see cref="DataRowVersion.Original"/> to access <see cref="Row"/></remarks>
/// <exception cref="DataException"><see cref="System.Data.DataView.get_AllowEdit"/> when setting a value.</exception>
/// <exception cref="IndexOutOfRangeException"><see cref="DataColumnCollection.get_Item(int)"/></exception>
[AllowNull]
public object this[int ndx]
{
get { return Row[ndx, RowVersionDefault]; }
set
{
if (!_dataView.AllowEdit && !IsNew)
{
throw ExceptionBuilder.CanNotEdit();
}
SetColumnValue(_dataView.Table!.Columns[ndx], value);
}
}
/// <summary>Gets the specified column value or related child view or sets a value in specified column.</summary>
/// <param name="property">Specified column or relation name when getting. Specified column name when setting.</param>
/// <exception cref="ArgumentException"><see cref="DataColumnCollection.get_Item(string)"/> when <paramref name="property"/> is ambiguous.</exception>
/// <exception cref="ArgumentException">Unmatched <paramref name="property"/> when getting a value.</exception>
/// <exception cref="DataException">Unmatched <paramref name="property"/> when setting a value.</exception>
/// <exception cref="DataException"><see cref="System.Data.DataView.get_AllowEdit"/> when setting a value.</exception>
[AllowNull]
public object this[string property]
{
get
{
DataColumn? column = _dataView.Table!.Columns[property];
if (null != column)
{
return Row[column, RowVersionDefault];
}
else if (_dataView.Table.DataSet != null && _dataView.Table.DataSet.Relations.Contains(property))
{
return CreateChildView(property);
}
throw ExceptionBuilder.PropertyNotFound(property, _dataView.Table.TableName);
}
set
{
DataColumn? column = _dataView.Table!.Columns[property];
if (null == column)
{
throw ExceptionBuilder.SetFailed(property);
}
if (!_dataView.AllowEdit && !IsNew)
{
throw ExceptionBuilder.CanNotEdit();
}
SetColumnValue(column, value);
}
}
// IDataErrorInfo stuff
string IDataErrorInfo.this[string colName] => Row.GetColumnError(colName);
string IDataErrorInfo.Error => Row.RowError;
/// <summary>
/// Gets the current version description of the <see cref="DataRow"/>
/// in relation to <see cref="System.Data.DataView.get_RowStateFilter"/>
/// </summary>
/// <returns>Either <see cref="DataRowVersion.Current"/> or <see cref="DataRowVersion.Original"/></returns>
public DataRowVersion RowVersion => (RowVersionDefault & ~DataRowVersion.Proposed);
/// <returns>Either <see cref="DataRowVersion.Default"/> or <see cref="DataRowVersion.Original"/></returns>
private DataRowVersion RowVersionDefault => Row.GetDefaultRowVersion(_dataView.RowStateFilter);
internal int GetRecord() => Row.GetRecordFromVersion(RowVersionDefault);
internal bool HasRecord() => Row.HasVersion(RowVersionDefault);
internal object GetColumnValue(DataColumn column) => Row[column, RowVersionDefault];
internal void SetColumnValue(DataColumn column, object? value)
{
if (_delayBeginEdit)
{
_delayBeginEdit = false;
Row.BeginEdit();
}
if (DataRowVersion.Original == RowVersionDefault)
{
throw ExceptionBuilder.SetFailed(column.ColumnName);
}
Row[column] = value;
}
/// <summary>
/// Returns a <see cref="System.Data.DataView"/>
/// for the child <see cref="System.Data.DataTable"/>
/// with the specified <see cref="System.Data.DataRelation"/>.
/// </summary>
/// <param name="relation">Specified <see cref="System.Data.DataRelation"/>.</param>
/// <param name="followParent">The parent object.</param>
/// <exception cref="ArgumentException">null or mismatch between <paramref name="relation"/> and <see cref="System.Data.DataView.get_Table"/>.</exception>
public DataView CreateChildView(DataRelation relation, bool followParent)
{
if (relation == null || relation.ParentKey.Table != DataView.Table)
{
throw ExceptionBuilder.CreateChildView();
}
RelatedView childView;
if (!followParent)
{
int record = GetRecord();
object[] values = relation.ParentKey.GetKeyValues(record);
childView = new RelatedView(relation.ChildColumnsReference, values);
}
else
{
childView = new RelatedView(this, relation.ParentKey, relation.ChildColumnsReference);
}
childView.SetIndex("", DataViewRowState.CurrentRows, null); // finish construction via RelatedView.SetIndex
childView.SetDataViewManager(DataView.DataViewManager);
return childView;
}
public DataView CreateChildView(DataRelation relation) =>
CreateChildView(relation, followParent: false);
/// <summary><see cref="CreateChildView(DataRelation)"/></summary>
/// <param name="relationName">Specified <see cref="System.Data.DataRelation"/> name.</param>
/// <param name="followParent">The parent object.</param>
/// <exception cref="ArgumentException">Unmatched <paramref name="relationName"/>.</exception>
public DataView CreateChildView(string relationName, bool followParent) =>
CreateChildView(DataView.Table!.ChildRelations[relationName]!, followParent);
public DataView CreateChildView(string relationName) =>
CreateChildView(relationName, followParent: false);
public DataRow Row => _row;
public void BeginEdit() => _delayBeginEdit = true;
public void CancelEdit()
{
DataRow tmpRow = Row;
if (IsNew)
{
_dataView.FinishAddNew(false);
}
else
{
tmpRow.CancelEdit();
}
_delayBeginEdit = false;
}
public void EndEdit()
{
if (IsNew)
{
_dataView.FinishAddNew(true);
}
else
{
Row.EndEdit();
}
_delayBeginEdit = false;
}
public bool IsNew => (_row == _dataView._addNewRow);
public bool IsEdit =>
Row.HasVersion(DataRowVersion.Proposed) || // It was edited or
_delayBeginEdit; // DataRowView.BegingEdit() was called, but not edited yet.
public void Delete() => _dataView.Delete(Row);
// When the PropertyChanged event happens, it must happen on the same DataRowView reference.
// This is so a generic event handler like Windows Presentation Foundation can redirect as appropriate.
// Having DataView.Equals is not sufficient for WPF, because two different instances may be equal but not equivalent.
// For DataRowView, if two instances are equal then they are equivalent.
public event PropertyChangedEventHandler? PropertyChanged;
// Do not try catch, we would mask users bugs. if they throw we would catch
internal void RaisePropertyChangedEvent(string propName) => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propName));
#region ICustomTypeDescriptor
AttributeCollection ICustomTypeDescriptor.GetAttributes() => new AttributeCollection(null);
string? ICustomTypeDescriptor.GetClassName() => null;
string? ICustomTypeDescriptor.GetComponentName() => null;
[RequiresUnreferencedCode("Generic TypeConverters may require the generic types to be annotated. For example, NullableConverter requires the underlying type to be DynamicallyAccessedMembers All.")]
TypeConverter? ICustomTypeDescriptor.GetConverter() => null;
[RequiresUnreferencedCode("The built-in EventDescriptor implementation uses Reflection which requires unreferenced code.")]
EventDescriptor? ICustomTypeDescriptor.GetDefaultEvent() => null;
[RequiresUnreferencedCode("PropertyDescriptor's PropertyType cannot be statically discovered.")]
PropertyDescriptor? ICustomTypeDescriptor.GetDefaultProperty() => null;
[RequiresUnreferencedCode("Design-time attributes are not preserved when trimming. Types referenced by attributes like EditorAttribute and DesignerAttribute may not be available after trimming.")]
object? ICustomTypeDescriptor.GetEditor(Type editorBaseType) => null;
EventDescriptorCollection ICustomTypeDescriptor.GetEvents() => new EventDescriptorCollection(null);
[RequiresUnreferencedCode("The public parameterless constructor or the 'Default' static field may be trimmed from the Attribute's Type.")]
EventDescriptorCollection ICustomTypeDescriptor.GetEvents(Attribute[]? attributes) => new EventDescriptorCollection(null);
[RequiresUnreferencedCode("PropertyDescriptor's PropertyType cannot be statically discovered.")]
PropertyDescriptorCollection ICustomTypeDescriptor.GetProperties() => ((ICustomTypeDescriptor)this).GetProperties(null);
[RequiresUnreferencedCode("PropertyDescriptor's PropertyType cannot be statically discovered. The public parameterless constructor or the 'Default' static field may be trimmed from the Attribute's Type.")]
PropertyDescriptorCollection ICustomTypeDescriptor.GetProperties(Attribute[]? attributes) =>
(_dataView.Table != null ? _dataView.Table.GetPropertyDescriptorCollection() : s_zeroPropertyDescriptorCollection);
object ICustomTypeDescriptor.GetPropertyOwner(PropertyDescriptor? pd) => this;
#endregion
}
}
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