private FilteredPaginationQuery Clone(FilteredPaginationQuery org)
{
var ret = JsonConvert.DeserializeObject <FilteredPaginationQuery>(JsonConvert.SerializeObject(org));
ret.SetAliasesAndValues(_queryParams);
return(ret);
}
/// <summary>
/// Builds a filtered paged result query from a filtered queryable, where server side paging is enforced.
/// </summary>
/// <typeparam name="TIn">The type of the t in.</typeparam>
/// <typeparam name="TOut">The type of the t out.</typeparam>
/// <param name="qry">The qry.</param>
/// <param name="request">The request.</param>
/// <param name="maxItemsPerResult">max items that should override the queries top.</param>
/// <param name="projection">Select projection</param>
/// <param name="serializeSettings">Map serialize settings</param>
/// <returns>Task<List<TOut>>.</returns>
public static IQueryable FilteredPagedResultsQuery <TIn, TOut>(this IQueryable <TIn> qry,
FilteredPaginationQuery request, int maxItemsPerResult,
Func <TIn, TOut> projection = null,
JsonSerializerSettings serializeSettings = null
)
where TOut : new()
{
var result = qry.BuildPagedQueryable(request, maxItemsPerResult)
.BuildFilteredQueryable(request)
.BuildOutputQueryable(projection, serializeSettings);
Console.WriteLine(result.Expression.ToString());
return(result);
}
private PaginationMetadata BuildResponseFromQuery(int resultCount, string baseUrl)
{
var requestQuery = new FilteredPaginationQuery();
requestQuery.SetAliasesAndValues(_queryParams);
var maxPageSize = (requestQuery.Top.IsNullOrZero()
? requestQuery.Skip.IsNullOrZero()
? resultCount
: requestQuery.Skip
: requestQuery.Top) ?? resultCount;
// If resultCount is 0 or empty then we are just going to display the structure.
// If resultCount is less than the max, and no query params have been passed then no need to have anything either.
if (resultCount == 0 || resultCount < maxPageSize && !_queryParams.Any())
{
return new PaginationMetadata
{
ResultCount = resultCount
}
}
;
var previousRc = requestQuery.RunningCount - resultCount;
SetRunningCount(requestQuery, resultCount);
FilteredPaginationQuery previousQuery = null;
FilteredPaginationQuery nextQuery = null;
if (requestQuery.Skip.IsNullOrZero() && requestQuery.Top.IsNullOrZero())
{
// No inputs, create new ones, no need to new up previousQuery.
// Set the top (take) to be the max and the skip to be what was just returned, resultCount.
var top = GetTop(requestQuery, maxPageSize);
nextQuery = Clone(requestQuery);
nextQuery.Skip = requestQuery.RunningCount;
nextQuery.Top = top;
nextQuery.RunningCount = requestQuery.RunningCount;
}
else if (!requestQuery.Top.IsNullOrZero() && requestQuery.Skip.IsNullOrZero())
{
// Only top specified, se we use it.
var top = GetTop(requestQuery, maxPageSize);
nextQuery = Clone(requestQuery);
nextQuery.Skip = requestQuery.RunningCount;
nextQuery.Top = top;
nextQuery.RunningCount = requestQuery.RunningCount;
}
else if (requestQuery.Top.HasValue)
{
var top = GetTop(requestQuery, maxPageSize);
var pre = GetPreviousSkip(requestQuery, maxPageSize);
var next = GetNextSkip(requestQuery, maxPageSize);
var nextRc = requestQuery.RunningCount;
previousQuery = Clone(requestQuery);
previousQuery.Top = top;
previousQuery.Skip = pre;
previousQuery.RunningCount = previousRc <= 0 ? null : previousRc;
// Do we need next?
if (resultCount >= maxPageSize)
{
nextQuery = Clone(requestQuery);
nextQuery.Skip = next;
nextQuery.Top = top;
nextQuery.RunningCount = nextRc;
}
}
if (nextQuery is not null)
{
nextQuery.Undefined = requestQuery.Undefined;
}
if (previousQuery is not null)
{
previousQuery.Undefined = previousQuery.Undefined;
}
var ret = new PaginationMetadata
{
ResultCount = resultCount,
Next = nextQuery is null
? null
: string.Format(baseUrl, nextQuery),
Previous = previousQuery is null
? null
: string.Format(baseUrl, previousQuery)
};
// if previous is empty and we do not have more than top, then next should be null as well.
if (ret.Previous is not null)
{
return(ret);
}
if (nextQuery is not null && resultCount < nextQuery.Top)
{
ret.Next = null;
}
return(ret);
}
