/// <summary>
/// Initializes a new instance of the <see cref="SortCollectionManager"/> class.
/// </summary>
/// <param name="sourceCollection">The collection of <see cref="SortDescriptor"/>s to manage</param>
/// <param name="descriptionCollection">The collection of <see cref="SortDescription"/>s to synchronize with the <paramref name="sourceCollection"/></param>
/// <param name="expressionCache">The cache with entries for the <see cref="SortDescriptor"/>s</param>
/// <param name="validationAction">The callback for validating items that are added or changed</param>
public SortCollectionManager(SortDescriptorCollection sourceCollection, SortDescriptionCollection descriptionCollection, ExpressionCache expressionCache, Action <SortDescriptor> validationAction)
{
if (sourceCollection == null)
{
throw new ArgumentNullException("sourceCollection");
}
if (descriptionCollection == null)
{
throw new ArgumentNullException("descriptionCollection");
}
if (expressionCache == null)
{
throw new ArgumentNullException("expressionCache");
}
if (validationAction == null)
{
throw new ArgumentNullException("validationAction");
}
this._sourceCollection = sourceCollection;
this._descriptionCollection = descriptionCollection;
this.ExpressionCache = expressionCache;
this.ValidationAction = (item) => validationAction((SortDescriptor)item);
this.AsINotifyPropertyChangedFunc = (item) => ((SortDescriptor)item).Notifier;
((INotifyCollectionChanged)descriptionCollection).CollectionChanged += this.HandleDescriptionCollectionChanged;
this.AddCollection(sourceCollection);
}
/// <summary>
/// Determines whether the <paramref name="sortDescriptions"/> are equivalent to the <paramref name="sortDescriptors"/>.
/// </summary>
/// <param name="sortDescriptions">The descriptions to compare</param>
/// <param name="sortDescriptors">The descriptors to compare</param>
/// <returns><c>true</c> if the collections are equivalent</returns>
public static bool AreEquivalent(SortDescriptionCollection sortDescriptions, SortDescriptorCollection sortDescriptors)
{
Debug.Assert((sortDescriptions != null) && (sortDescriptors != null), "Both should be non-null.");
if (sortDescriptions.Count != sortDescriptors.Count)
{
return(false);
}
for (int i = 0, count = sortDescriptions.Count; i < count; i++)
{
if (!SortCollectionManager.AreEquivalent(sortDescriptions[i], sortDescriptors[i]))
{
return(false);
}
}
return(true);
}
/// <summary>
/// Resets the <paramref name="sortDescriptors"/> collection to match the <paramref name="sortDescriptions"/> collection.
/// </summary>
/// <param name="sortDescriptions">The collection to match</param>
/// <param name="sortDescriptors">The collection to reset</param>
private static void ResetToSortDescriptions(SortDescriptionCollection sortDescriptions, SortDescriptorCollection sortDescriptors)
{
sortDescriptors.Clear();
foreach (SortDescription description in sortDescriptions)
{
sortDescriptors.Add(SortCollectionManager.GetDescriptorFromDescription(description));
}
}
/// <summary>
/// Resets the <paramref name="sortDescriptions"/> collection to match the <paramref name="sortDescriptors"/> collection.
/// </summary>
/// <param name="sortDescriptions">The collection to reset</param>
/// <param name="sortDescriptors">The collection to match</param>
private static void ResetToSortDescriptors(SortDescriptionCollection sortDescriptions, SortDescriptorCollection sortDescriptors)
{
sortDescriptions.Clear();
foreach (SortDescriptor descriptor in sortDescriptors)
{
SortDescription?description = SortCollectionManager.GetDescriptionFromDescriptor(descriptor);
if (description.HasValue)
{
sortDescriptions.Add(description.Value);
}
}
}
/// <summary>
/// Composes an <see cref="EntityQuery" /> for sorting and grouping purposes.
/// </summary>
/// <param name="source">The queryable source.</param>
/// <param name="groupDescriptors">The group descriptors.</param>
/// <param name="sortDescriptors">The sort descriptors.</param>
/// <param name="expressionCache">Cache for storing built expressions</param>
/// <returns>The composed <see cref="EntityQuery" />.</returns>
public static EntityQuery OrderBy(
EntityQuery source,
GroupDescriptorCollection groupDescriptors,
SortDescriptorCollection sortDescriptors,
ExpressionCache expressionCache)
{
Debug.Assert(source != null, "Unexpected null source");
Debug.Assert(sortDescriptors != null, "Unexpected null sortDescriptors");
Debug.Assert(groupDescriptors != null, "Unexpected null groupDescriptors");
bool hasOrderBy = false;
// check the GroupDescriptors first
foreach (GroupDescriptor groupDescriptor in groupDescriptors)
{
if (groupDescriptor != null && groupDescriptor.PropertyPath != null)
{
Debug.Assert(expressionCache.ContainsKey(groupDescriptor), "There should be a cached group expression");
// check to see if we sort by the same parameter in desc order
bool sortAsc = true;
foreach (SortDescriptor sortDescriptor in sortDescriptors)
{
if (sortDescriptor != null)
{
string sortDescriptorPropertyPath = sortDescriptor.PropertyPath;
string groupDescriptorPropertyPath = groupDescriptor.PropertyPath;
if (sortDescriptorPropertyPath != null &&
sortDescriptorPropertyPath.Equals(groupDescriptorPropertyPath))
{
if (sortDescriptor.Direction == ListSortDirection.Descending)
{
sortAsc = false;
}
break;
}
}
}
string orderMethodName = (!hasOrderBy ? "OrderBy" : "ThenBy");
if (!sortAsc)
{
orderMethodName += "Descending";
}
source = OrderBy(source, orderMethodName, expressionCache[groupDescriptor]);
hasOrderBy = true;
}
}
// then check the SortDescriptors
foreach (SortDescriptor sortDescriptor in sortDescriptors)
{
if (sortDescriptor != null)
{
Debug.Assert(expressionCache.ContainsKey(sortDescriptor), "There should be a cached sort expression");
string orderMethodName = (!hasOrderBy ? "OrderBy" : "ThenBy");
if (sortDescriptor.Direction == ListSortDirection.Descending)
{
orderMethodName += "Descending";
}
source = OrderBy(source, orderMethodName, expressionCache[sortDescriptor]);
hasOrderBy = true;
}
}
return(source);
}
