/// <summary>
/// Returns last sibling of given item, or default value if there are no siblings.
/// </summary>
/// <param name="collection">Sequence to filter. </param>
/// <param name="item">Item to find siblings for. </param>
/// <typeparam name="TResult">Type of sequence containing item siblings. Should implement <see cref="IHasTreeEntry"/>. </typeparam>
/// <typeparam name="TFilter">Type of referenced item to use in query. Should implement <see cref="IHasTreeEntry"/>. </typeparam>
/// <returns>last sibling of given item or default value if there are no siblings. </returns>
public static TResult LastSiblingOrDefault <TResult, TFilter>(this IQueryable <TResult> collection, TFilter item)
where TResult : IHasTreeEntry
where TFilter : IHasTreeEntry
{
return(collection.Where(i => i.TreeEntry, NestedIntervalsSpec.SiblingsAfter(item.TreeEntry, true))
.OrderBy(i => i.TreeEntry.Nv).LastOrDefault());
}
/// <summary>
/// Returns first root item in given collection or default value if there are no items in hierarchy.
/// </summary>
/// <param name="collection">sequence to find first root. </param>
/// <typeparam name="TResult">Type of sequence containing root item. Should implement <see cref="IHasTreeEntry"/>. </typeparam>
/// <returns>First root item or default value if there are no items in hierarchy. </returns>
public static TResult LastRootOrDefault <TResult>(this IQueryable <TResult> collection)
where TResult : IHasTreeEntry
{
return(collection
.Where(c => c.TreeEntry, NestedIntervalsSpec.RootEntries())
.OrderByDescending(i => i.TreeEntry.Nv)
.FirstOrDefault());
}
/// <summary>
/// Filters a sequence of values to select elements by it's positions relative to parent.
/// </summary>
/// <example>
/// For path {2, 1, 3} it will select 2nd root item, then first child of 2nd root item, then third child of 2nd root's first child.
/// </example>
/// <param name="collection">Sequence to filter. </param>
/// <param name="positionsPath">Elements positions path relative to it's parent. Position indexes starting from 1.</param>
/// <typeparam name="TResult">Type of sequence to filter. Should implement <see cref="IHasTreeEntry"/>. </typeparam>
/// <returns>Sequence of items filtered by given positions path, relative to parents. </returns>
public static IQueryable <TResult> ByPositionsPath <TResult>(
this IQueryable <TResult> collection,
IEnumerable <long> positionsPath)
where TResult : IHasTreeEntry
{
return(collection
.Where((i) => i.TreeEntry, NestedIntervalsSpec.ElementsByPositionsPath(positionsPath))
.OrderBy(i => i.TreeEntry.Nv));
}
/// <summary>
/// Filter a sequence of values to return sibling elements of given item, positioned after it.
/// Item considered as sibling if it's children of same parent item.
/// </summary>
/// <param name="collection">Sequence to filter. </param>
/// <param name="item">Item to find siblings for. </param>
/// <param name="includeSelf">Whether or not to include referenced item itself in list of siblings. false by default. </param>
/// <typeparam name="TResult">Type of sequence containing item siblings. Should implement <see cref="IHasTreeEntry"/>. </typeparam>
/// <typeparam name="TFilter">Type of referenced item to use in query. Should implement <see cref="IHasTreeEntry"/>. </typeparam>
/// <returns>Sequence of sibling items of given item, positioned after it. </returns>
public static IQueryable <TResult> SiblingsAfter <TResult, TFilter>(
this IQueryable <TResult> collection,
TFilter item,
bool includeSelf = false)
where TResult : IHasTreeEntry
where TFilter : IHasTreeEntry
{
return(collection.Where(i => i.TreeEntry, NestedIntervalsSpec.SiblingsAfter(item.TreeEntry, includeSelf)));
}
/// <summary>
/// Filters a sequence of values to return descendants of all given items.
/// </summary>
/// <param name="collection">sequence to filter. </param>
/// <param name="items">sequence of parent items to find it's descendants. </param>
/// <param name="depth">Level of inheritance to filter descendants.
/// 1 returns only direct children, 2 - children of children etc.
/// -1 to return all descendants down to deepest leaves.
/// -1 by default. </param>
/// <param name="includeSelf">Whether or not to include given parent items itself in list. false by default. </param>
/// <typeparam name="TResult">Type of sequence containing ancestors elements. Should implement <see cref="IHasTreeEntry"/>. </typeparam>
/// <typeparam name="TFilter">Type of referenced items to use in filter. Should implement <see cref="IHasTreeEntry"/>. </typeparam>
/// <returns>Sequence of descendants of given items. </returns>
public static IQueryable <TResult> DescendantsOfAny <TResult, TFilter>(
this IQueryable <TResult> collection,
IEnumerable <TFilter> items,
int depth = -1,
bool includeSelf = false)
where TResult : IHasTreeEntry
where TFilter : IHasTreeEntry
{
return(collection.Where(i => i.TreeEntry, NestedIntervalsSpec.DescendantsOfAll(items, depth, includeSelf)));
}
/// <summary>
/// Filters a sequence of values to include only ancestors (parents and all parents of parents) of given item.
/// </summary>
/// <param name="collection">sequence to filter. </param>
/// <param name="item">child item to find it's ancestors. </param>
/// <param name="depth">Level of inheritance to filter ancestors.
/// 1 returns only direct parents, 2 - parents of parents etc.
/// -1 to return all ancestors up to root items.
/// -1 by default. </param>
/// <param name="includeSelf">Whether or not to include given child item itself in list. false by default. </param>
/// <typeparam name="TResult">Type of sequence containing ancestors elements. Should implement <see cref="IHasTreeEntry"/>. </typeparam>
/// <typeparam name="TFilter">Type of referenced item to use in filter. Should implement <see cref="IHasTreeEntry"/>. </typeparam>
/// <returns>Sequence of ancestors of given item. </returns>
public static IQueryable <TResult> AncestorsOf <TResult, TFilter>(
this IQueryable <TResult> collection,
TFilter item,
int depth = -1,
bool includeSelf = false)
where TResult : IHasTreeEntry
where TFilter : IHasTreeEntry
{
return(collection.Where(i => i.TreeEntry, NestedIntervalsSpec.AncestorsOf(item, depth, includeSelf)));
}
/// <summary>
/// Filters a sequence of values to include only ancestors (parents and all parents of parents) of given item.
/// </summary>
/// <param name="collection">sequence to filter. </param>
/// <param name="navigateExpr">Property expression returning path to IHasTreeEntry item. </param>
/// <param name="item">child item to find it's ancestors. </param>
/// <param name="depth">Level of inheritance to filter ancestors.
/// 1 returns only direct parents, 2 - parents of parents etc.
/// -1 to return all ancestors up to root items.
/// -1 by default. </param>
/// <param name="includeSelf">Whether or not to include given child item itself in list. false by default. </param>
/// <typeparam name="TResult">Type of sequence containing ancestors elements. </typeparam>
/// <typeparam name="TFilter">Type of referenced item to use in filter. Should implement <see cref="IHasTreeEntry"/>. </typeparam>
/// <returns>Sequence of ancestors of given item. </returns>
public static IQueryable <TResult> AncestorsOf <TResult, TFilter>(
this IQueryable <TResult> collection,
Expression <Func <TResult, IHasTreeEntry> > navigateExpr,
TFilter item,
int depth = -1,
bool includeSelf = false)
where TFilter : IHasTreeEntry
{
return(collection.Where(navigateExpr.Navigate(i => i.TreeEntry), NestedIntervalsSpec.AncestorsOf(item, depth, includeSelf)));
}
/// <summary>
/// Filters a sequence of values to return descendants of all given items.
/// </summary>
/// <param name="collection">sequence to filter. </param>
/// <param name="navigateExpr">Property expression returning path to IHasTreeEntry item. </param>
/// <param name="items">sequence of parent items to find it's descendants. </param>
/// <param name="depth">Level of inheritance to filter descendants.
/// 1 returns only direct children, 2 - children of children etc.
/// -1 to return all descendants down to deepest leaves.
/// -1 by default. </param>
/// <param name="includeSelf">Whether or not to include given parent items itself in list. false by default. </param>
/// <typeparam name="TResult">Type of sequence containing descendants elements. Should implement <see cref="IHasTreeEntry"/>. </typeparam>
/// <typeparam name="TFilter">Type of referenced items to use in filter. Should implement <see cref="IHasTreeEntry"/>. </typeparam>
/// <returns>Sequence of descendants of given items. </returns>
public static IQueryable <TResult> DescendantsOfAny <TResult, TFilter>(
this IQueryable <TResult> collection,
Expression <Func <TResult, IHasTreeEntry> > navigateExpr,
IEnumerable <TFilter> items,
int depth = -1,
bool includeSelf = false)
where TFilter : IHasTreeEntry
{
return(collection.Where(navigateExpr.Navigate(i => i.TreeEntry), NestedIntervalsSpec.DescendantsOfAll(items, depth, includeSelf)));
}
/// <summary>
/// Returns sibling item of given item, positioned right after it, or default value if there are no next sibling.
/// </summary>
/// <param name="collection">Sequence to filter. </param>
/// <param name="item">Item to find siblings for. </param>
/// <typeparam name="TResult">Type of sequence containing item siblings. Should implement <see cref="IHasTreeEntry"/>. </typeparam>
/// <typeparam name="TFilter">Type of referenced item to use in query. Should implement <see cref="IHasTreeEntry"/>. </typeparam>
/// <returns>sibling item of given item, positioned right after it, or default value if there are no next sibling. </returns>
public static TResult NextSiblingOrDefault <TResult, TFilter>(this IQueryable <TResult> collection, TFilter item)
where TResult : IHasTreeEntry
where TFilter : IHasTreeEntry
{
return(collection.Where(i => i.TreeEntry, NestedIntervalsSpec.NextSiblingOf(item.TreeEntry)).FirstOrDefault());
}
