public Task BindModelAsync(ModelBindingContext bindingContext)
{
var valueName = string.IsNullOrEmpty(bindingContext.ModelName)
? bindingContext.ModelMetadata.Name
: bindingContext.ModelName;
var limit = PagingParameters.DefaultLimit;
var cursor = PagingCursor.Start;
if (bindingContext.TryGetValue <int>("limit", out var limitResult))
{
limit = limitResult.Value;
}
if (bindingContext.TryGetStringValue("cursor", out var cursorResult))
{
cursor = new PagingCursor(cursorResult.Value);
}
var pagingParameters = new PagingParameters(cursor, limit).Coerce();
bindingContext.ModelState.MarkFieldValid(valueName);
bindingContext.Result = ModelBindingResult.Success(pagingParameters);
return(Task.CompletedTask);
}
public static async Task <PagingResult <T> > ToPagedResult <T>(this IQueryable <T> input, PagingParameters pagingParameters, CancellationToken cancellationToken)
{
if (input == null)
{
throw new ArgumentNullException(nameof(input));
}
if (pagingParameters == null)
{
throw new ArgumentNullException(nameof(pagingParameters));
}
var offset = pagingParameters.Cursor.IsStart ? 0 : long.Parse(pagingParameters.Cursor.ToString());
var totalCount = await input.LongCountAsync(cancellationToken).ConfigureAwait(false);
var resultItems = await input.Skip((int)offset).Take(pagingParameters.Limit).ToListAsync(cancellationToken)
.ConfigureAwait(false);
var continuationCursor = PagingCursor.FromOffset(offset + resultItems.Count);
return(new PagingResult <T>(resultItems, totalCount, continuationCursor));
}
