public override void OnFormatting(ActionContext context)
{
base.OnFormatting(context);
NexusatAspNetCoreOptions options = GetAspNetCoreOptions(context.HttpContext);
Navigation?.SetLinks(options, context.HttpContext);
}
/// <summary>
/// Sets the pagination links.
/// </summary>
/// <param name="options">Application Global settings.</param>
/// <param name="httpContext">The Http Context of the request</param>
internal void SetLinks(NexusatAspNetCoreOptions options, HttpContext context)
{
string requestUrl = context.Request.GetEncodedPathAndQuery();
// Only one of the following condition can hold
/// <see cref="Builders.ApiEnumResponseBuilder{T}"/>
Debug.Assert(ItemsCount.HasValue ^ HasNextPage);
PageSize = PaginationCursor.PageSize;
if (PaginationCursor.IsPageSizeBounded) // If unbounded links are not generated
{
Links = new PaginationLinks();
var linkBuilder = new PaginationInfoLinkBuilder(
context.Request.GetEncodedPathAndQuery(),
options.PaginationPageIndexName,
options.PaginationPageSizeName,
PaginationCursor.PageSize
);
// First
Links.First = linkBuilder.GetLink(1);
// Current
Links.Current = linkBuilder.GetLink(PaginationCursor.PageIndex);
// Previous
if (PaginationCursor.PageIndex > 1)
{
Links.Previous = linkBuilder.GetLink(PaginationCursor.PageIndex - 1);
}
if (ItemsCount.HasValue)
{ // calculate links and pageCount
int pageCount =
(ItemsCount.Value + PaginationCursor.PageSize - 1) / PaginationCursor.PageSize;
PagesCount = pageCount;
if (pageCount > PaginationCursor.PageIndex)
{
// Next
Links.Next = linkBuilder.GetLink(PaginationCursor.PageIndex + 1);
}
// Last
Links.Last = linkBuilder.GetLink(pageCount);
}
else if (HasNextPage) // implies hasn't itemsCount
{ // calculate links except the "last"
Links.Next = linkBuilder.GetLink(PaginationCursor.PageIndex + 1);
}
}
else // Unbounded requests have only 1 page of data
{
PagesCount = 1;
}
}
private static void ParsePageCursor(NexusatAspNetCoreOptions options, IQueryCollection query, out int?pageSize, out int?pageIndex)
{
StringValues values;
pageSize = pageIndex = null;
int _size, _index;
if (query.TryGetValue(options.PaginationPageSizeName, out values))
{
if (!int.TryParse(values[0], out _size))
{
var ex = new BadRequestResponseException("KO_BAD_PAGE_SIZE");
ex.Description = "Page Size is not a valid integer";
throw ex;
}
if (_size < 0)
{
var ex = new BadRequestResponseException("KO_BAD_PAGE_SIZE");
ex.Description = "Page Size must be a non negative integer";
throw ex;
}
pageSize = _size;
}
if (query.TryGetValue(options.PaginationPageIndexName, out values))
{
if (!int.TryParse(values[0], out _index))
{
var ex = new BadRequestResponseException("KO_BAD_PAGE_INDEX");
ex.Description = "Page Index is not a valid integer";
throw ex;
}
if (_index < 1)
{
var ex = new BadRequestResponseException("KO_BAD_PAGE_INDEX");
ex.Description = "Page Index must be a positive integer";
throw ex;
}
pageIndex = _index;
}
}
