Using ValueTuple returns Item1,Item2 why?

Question

The next api returns in Postmen and to the client item1,item2 While I am using ValueTuple to change the names (the names not so important, but I can’t return item1,item2)

public async Task<(List<CategoryFilterResponseDTO> categoryFilters, string MetaDataDescription)> GetCategoryFilterPage([FromBody]categoryFilterRequestDTO categoryFilterRequest)
{
    var logItem = new LogDTO();
    var result = await _service.GetCategoryFilterPage(categoryFilterRequest);

    try
    {
        OnStart(logItem, new object[] { categoryFilterRequest });
        var categoryFilters = result.categoryFilters;
        var MetaDataDescription = result.MetaDataDescription;


        return (categoryFilters: categoryFilters, MetaDataDescription: MetaDataDescription);

    }
}

the method:

public async Task<(List<CategoryFilterResponseDTO> categoryFilters, string MetaDataDescription)> GetCategoryFilterPage(categoryFilterRequestDTO categoryFilterRequestDTO)
{
    List<CategoryFilterResponseDTO> categoryFilter = new List<CategoryFilterResponseDTO>();
    List<FavoriteDTO> isFavorite = null;
    string MetaDataDescription = "";
    (List<FilterSortDTO<FlatSearchCategory>>, int) searchCategory = await _clubRepo.CategoryFilterPage(categoryFilterRequestDTO);//BranchesCount
    if (searchCategory.Item2 == 0)
    {
        MetaDataDescription = GetCategoryDetails(categoryFilterRequestDTO.CategoryFirstFatherID.Value).CategoryName;
        return (categoryFilters: categoryFilter, MetaDataDescription: MetaDataDescription);
    }

Presumably Web API doesn't use reflection to work out the element names of the return types. Which version of ASP.NET Core is this? It's possible that it's been improved in later versions. — Jon Skeet, Nov 11 '19 at 10:03
Have just tried and ASP.NET Core 3 is even worse than 2 for this - it returns an empty JSON object. — Jon Skeet, Nov 11 '19 at 10:15
@JonSkeet I guess that's because `System.Text.Json` doesn't serialise fields right now. — Kirk Larkin, Nov 11 '19 at 10:42

score 2 · Answer 1 · edited Nov 11 '19 at 10:43

2

You can change your return to the following:

return Ok(new
{
    categoryFilters = categoryFilter,
    metaDataDescription = MetaDataDescription
});

You will need to change your return type to ActionResult or similar as well.

edited Nov 11 '19 at 10:43

Kirk Larkin

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answered Nov 11 '19 at 10:06

Kristofer

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score 1 · Answer 2 · answered Nov 11 '19 at 13:15

1

Because that's the name of the fields on a ValueTuple<,>.

The names given to the values are only available to source code.

answered Nov 11 '19 at 13:15

Paulo Morgado

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Using ValueTuple returns Item1,Item2 why?

2 Answers2