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//------------------------------------------------------------------------------
// <copyright file="EnumRowCollectionExtensions.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
// <owner current="true" primary="true">Microsoft</owner>
// <owner current="true" primary="false">Microsoft</owner>
//------------------------------------------------------------------------------
using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Globalization;
using System.Diagnostics;
namespace System.Data
{
/// <summary>
/// This static class defines the extension methods that add LINQ operator functionality
/// within IEnumerableDT and IOrderedEnumerableDT.
/// </summary>
public static class EnumerableRowCollectionExtensions
{
/// <summary>
/// LINQ's Where operator for generic EnumerableRowCollection.
/// </summary>
public static EnumerableRowCollection<TRow> Where<TRow>(
this EnumerableRowCollection<TRow> source,
Func<TRow, bool> predicate)
{
EnumerableRowCollection<TRow> edt =
new EnumerableRowCollection<TRow>(source, Enumerable.Where<TRow>(source, predicate), null); //copy constructor
edt.AddPredicate(predicate);
return edt;
}
/// <summary>
/// LINQ's OrderBy operator for generic EnumerableRowCollection.
/// </summary>
public static OrderedEnumerableRowCollection<TRow> OrderBy<TRow, TKey>(
this EnumerableRowCollection<TRow> source,
Func<TRow, TKey> keySelector)
{
IEnumerable<TRow> ie = Enumerable.OrderBy<TRow, TKey>(source, keySelector);
OrderedEnumerableRowCollection<TRow> edt = new OrderedEnumerableRowCollection<TRow>(source, ie);
edt.AddSortExpression(keySelector, false, true);
return edt;
}
/// <summary>
/// LINQ's OrderBy operator for generic EnumerableRowCollection.
/// </summary>
public static OrderedEnumerableRowCollection<TRow> OrderBy<TRow, TKey>(
this EnumerableRowCollection<TRow> source,
Func<TRow, TKey> keySelector,
IComparer<TKey> comparer)
{
IEnumerable<TRow> ie = Enumerable.OrderBy<TRow, TKey>(source, keySelector, comparer);
OrderedEnumerableRowCollection<TRow> edt = new OrderedEnumerableRowCollection<TRow>(source, ie);
edt.AddSortExpression(keySelector, comparer, false, true);
return edt;
}
/// <summary>
/// LINQ's OrderByDescending operator for generic EnumerableRowCollection.
/// </summary>
public static OrderedEnumerableRowCollection<TRow> OrderByDescending<TRow, TKey>(
this EnumerableRowCollection<TRow> source,
Func<TRow, TKey> keySelector)
{
IEnumerable<TRow> ie = Enumerable.OrderByDescending<TRow, TKey>(source, keySelector);
OrderedEnumerableRowCollection<TRow> edt = new OrderedEnumerableRowCollection<TRow>(source, ie);
edt.AddSortExpression(keySelector, true, true);
return edt;
}
/// <summary>
/// LINQ's OrderByDescending operator for generic EnumerableRowCollection.
/// </summary>
public static OrderedEnumerableRowCollection<TRow> OrderByDescending<TRow, TKey>(
this EnumerableRowCollection<TRow> source,
Func<TRow, TKey> keySelector,
IComparer<TKey> comparer)
{
IEnumerable<TRow> ie = Enumerable.OrderByDescending<TRow, TKey>(source, keySelector, comparer);
OrderedEnumerableRowCollection<TRow> edt = new OrderedEnumerableRowCollection<TRow>(source, ie);
edt.AddSortExpression(keySelector, comparer, true, true);
return edt;
}
/// <summary>
/// LINQ's ThenBy operator for generic EnumerableRowCollection.
/// </summary>
public static OrderedEnumerableRowCollection<TRow> ThenBy<TRow, TKey>(
this OrderedEnumerableRowCollection<TRow> source,
Func<TRow, TKey> keySelector)
{
IEnumerable<TRow> ie =
Enumerable.ThenBy<TRow, TKey>((IOrderedEnumerable<TRow>)source.EnumerableRows, keySelector);
OrderedEnumerableRowCollection<TRow> edt =
new OrderedEnumerableRowCollection<TRow>((EnumerableRowCollection<TRow>)source, ie);
edt.AddSortExpression(keySelector, /*isDesc*/ false, /*isOrderBy*/ false);
return edt;
}
/// <summary>
/// LINQ's ThenBy operator for generic EnumerableRowCollection.
/// </summary>
public static OrderedEnumerableRowCollection<TRow> ThenBy<TRow, TKey>(
this OrderedEnumerableRowCollection<TRow> source,
Func<TRow, TKey> keySelector,
IComparer<TKey> comparer)
{
IEnumerable<TRow> ie =
Enumerable.ThenBy<TRow, TKey>((IOrderedEnumerable<TRow>)source.EnumerableRows, keySelector, comparer);
OrderedEnumerableRowCollection<TRow> edt =
new OrderedEnumerableRowCollection<TRow>((EnumerableRowCollection<TRow>)source, ie);
edt.AddSortExpression(keySelector, comparer, false, false);
return edt;
}
/// <summary>
/// LINQ's ThenByDescending operator for generic EnumerableRowCollection.
/// </summary>
public static OrderedEnumerableRowCollection<TRow> ThenByDescending<TRow, TKey>(
this OrderedEnumerableRowCollection<TRow> source,
Func<TRow, TKey> keySelector)
{
IEnumerable<TRow> ie =
Enumerable.ThenByDescending<TRow, TKey>((IOrderedEnumerable<TRow>)source.EnumerableRows, keySelector);
OrderedEnumerableRowCollection<TRow> edt =
new OrderedEnumerableRowCollection<TRow>((EnumerableRowCollection<TRow>)source, ie);
edt.AddSortExpression(keySelector, /*desc*/ true, false);
return edt;
}
/// <summary>
/// LINQ's ThenByDescending operator for generic EnumerableRowCollection.
/// </summary>
public static OrderedEnumerableRowCollection<TRow> ThenByDescending<TRow, TKey>(
this OrderedEnumerableRowCollection<TRow> source,
Func<TRow, TKey> keySelector,
IComparer<TKey> comparer)
{
IEnumerable<TRow> ie =
Enumerable.ThenByDescending<TRow, TKey>((IOrderedEnumerable<TRow>)source.EnumerableRows, keySelector, comparer);
OrderedEnumerableRowCollection<TRow> edt =
new OrderedEnumerableRowCollection<TRow>((EnumerableRowCollection<TRow>)source, ie);
edt.AddSortExpression(keySelector, comparer, true, false);
return edt;
}
/// <summary>
/// Executes a Select (Projection) on EnumerableDataTable. If the selector returns a different
/// type than the type of rows, then AsLinqDataView is disabled, and the returning EnumerableDataTable
/// represents an enumerable over the LINQ Query.
/// </summary>
public static EnumerableRowCollection<S> Select<TRow, S>(
this EnumerableRowCollection<TRow> source,
Func<TRow, S> selector)
{
//Anonymous type or some other type
//The only thing that matters from this point on is _enumerableRows
IEnumerable<S> typedEnumerable = Enumerable.Select<TRow, S>(source, selector);
// Dont need predicates or sort expression from this point on since we know
// AsLinqDataView is disabled.
return new EnumerableRowCollection<S>(((object)source) as EnumerableRowCollection<S>,
typedEnumerable,
((object)selector) as Func<S,S>);
}
/// <summary>
/// Casts an EnumerableDataTable_TSource into EnumerableDataTable_TResult
/// </summary>
public static EnumerableRowCollection<TResult> Cast<TResult>(this EnumerableRowCollection source)
{
// Since Cast does not have the signature Cast_T_R(..) this call is routed
// through the non-generic base class EnumerableDataTable
if ((null != source) && source.ElementType.Equals(typeof(TResult)))
{
return (EnumerableRowCollection<TResult>)(object)source;
}
else
{ //Anonymous type or some other type
//The only thing that matters from this point on is _enumerableRows
IEnumerable<TResult> typedEnumerable = Enumerable.Cast<TResult>(source);
EnumerableRowCollection<TResult> newEdt = new EnumerableRowCollection<TResult>(
typedEnumerable,
typeof(TResult).IsAssignableFrom(source.ElementType) && typeof(DataRow).IsAssignableFrom(typeof(TResult)),
source.Table);
return newEdt;
}
}
} //end class
}
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