/// <summary>
/// Returns the first item of the <paramref name="query"/> as the generic Page type and null if no items were returned.
/// </summary>
/// <param name="query">The current DocumentQuery</param>
/// <param name="token">Optional cancellation token</param>
/// <returns></returns>
public static async Task <TDocument?> FirstOrDefaultAsync <TDocument>(this DocumentQuery <TDocument> query, CancellationToken token = default)
where TDocument : TreeNode, new()
{
var result = await query.GetEnumerableTypedResultAsync(cancellationToken : token);
return(result?.FirstOrDefault());
}
/// <summary>
/// Converts the <paramref name="query"/> to a <see cref="List{TDocument}"/> of the generic Page type
/// </summary>
/// <param name="query">The current DocumentQuery</param>
/// <param name="projection">Mapping function from <typeparamref name="TDocument" /> to <typeparamref name="TReturn" /></param>
/// <param name="token">Optional cancellation token</param>
/// <returns></returns>
public static async Task <IList <TReturn> > ToListAsync <TDocument, TReturn>(
this DocumentQuery <TDocument> query,
Func <TDocument, TReturn> projection,
CancellationToken token = default)
where TDocument : TreeNode, new()
{
var result = await query.GetEnumerableTypedResultAsync(cancellationToken : token);
return(result.Select(projection).ToList());
}
/// <summary>
/// Returns the first item of the <paramref name="query"/> as the generic Page type and null if no items were returned.
/// </summary>
/// <param name="query">The current DocumentQuery</param>
/// <param name="projection">Mapping function from <typeparamref name="TDocument" /> to <typeparamref name="TReturn" /></param>
/// <param name="token">Optional cancellation token</param>
/// <returns></returns>
public static async Task <TReturn?> FirstOrDefaultAsync <TDocument, TReturn>(
this DocumentQuery <TDocument> query,
Func <TDocument, TReturn> projection,
CancellationToken token = default)
where TDocument : TreeNode, new()
where TReturn : class
{
var result = await query.GetEnumerableTypedResultAsync(cancellationToken : token);
return(result?.Select(projection).FirstOrDefault());
}