CODEWITHSUNDEEP
c#asp.net-coreasp.net-web-api.net-core
Ahmad Alaa
Ahmad Alaa

Reputation: 817

Read created headers on result executed

I'm using Asp.Net Core 3.1 as a Rest Api Service. I used memory cache to store result after calling actions,
The problem is i created custom headers on actions before return the object and i also need to cache this headers, but i cant access it while using OnResultExecuted on action filters
Web api : 

[CachingResource(Prefixe = CachingPrefixes.Contents)]
[HttpGet("{typeId}")]
public async Task<IActionResult> Get(int typeId, [FromQuery]GetContentsParams prms)
{
    ApiPagedList<C_ContentLoc> items = await _rep.GetItemsLocPaged(typeId, prms);
    IEnumerable<ContentDto> dto = _mapper.Map<IEnumerable<ContentDto>>(items);

    Response.AddPaginationHeader(items.CurrentPage, items.PageSize, items.TotalCount, items.TotalPages);

    return Ok(dto);
}


Add pagination header extension : 

public static void AddPaginationHeader(this HttpResponse response, int currentPage, int pageSize, int totalItems, int numberOfPages)
{
    var paginationHeader = new PaginationHeader(currentPage, pageSize, numberOfPages, totalItems);
    //create header object
    var camelCaseFormatter = new JsonSerializerSettings();
    camelCaseFormatter.ContractResolver = new CamelCasePropertyNamesContractResolver();
    response.Headers.Add("Pagination", JsonConvert.SerializeObject(paginationHeader, camelCaseFormatter));
    //give the client access to this header
    response.AddExposeHeader("Pagination");
}


Caching resource filter on result executed : 

public override void OnResultExecuted(ResultExecutedContext context)
{
    if (!isInCache && !string.IsNullOrEmpty(cacheKey))
    {
        if (context.Result is OkObjectResult result)
        {
            bool isExist = context.HttpContext.Request.Headers.TryGetValue("Pagination", out StringValues vs);
            if(isExist)
            {
                //no result !
            }
            _cache.Set(cacheKey, result.Value);
            CachingHelper.SaveCacheKeys(Prefixe, cacheKey, _cache);
        }
    }
}

Upvotes: 1

Views: 276

Answers (1)

Roman Marusyk
Roman Marusyk

Reputation: 24609

You need to read Response headers, but not Request

bool isExist = context.HttpContext.Response.Headers.TryGetValue("Pagination", out StringValues vs);

Upvotes: 2

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