C#•3y ago

Object null when using the same action controller

I have my GetById Action controller giving the result like this when request directly from it notice that the Breed not null (the first image)

[HttpGet("{animalId}")]
        public async Task<IActionResult> GetById(int animalId, CancellationToken cancellationToken = default)
        {
            var animal = await _animalRepository.FindByIdAsync(animalId, cancellationToken);
            return animal != null ? Ok(_mapper.Map<AnimalDTO>(animal)) : NotFound("Unable to find the requested animal"); 
        }

[HttpGet("{animalId}")]
        public async Task<IActionResult> GetById(int animalId, CancellationToken cancellationToken = default)
        {
            var animal = await _animalRepository.FindByIdAsync(animalId, cancellationToken);
            return animal != null ? Ok(_mapper.Map<AnimalDTO>(animal)) : NotFound("Unable to find the requested animal"); 
        }

And I have the Create Action Controller which basically using the GetById to give me the animal using the below return

return CreatedAtAction(nameof(GetById), new { Id = animal.Id }, _mapper.Map<AnimalDTO>(animal));

return CreatedAtAction(nameof(GetById), new { Id = animal.Id }, _mapper.Map<AnimalDTO>(animal));

And the second picture is the result I got which is the breed completely null

44 Replies

Angius•3y ago

You need to .Include() related models Or better yet, .Select() the whole thing into a DTO So, a fast way:

var animal = await _context.Animals
    .Where(a => a.Id == id)
    .Include(a => a.Breed)
    .FirstOrDefaultAsync();

var animal = await _context.Animals
    .Where(a => a.Id == id)
    .Include(a => a.Breed)
    .FirstOrDefaultAsync();

and a proper way:

var animal = await _context.Animals
    .Where(a => a.Id == id)
    .Select(a => new AnimalDto {
        Name = a.Name,
        // ...
        Breed = new BreedDto {
            Name = a.Breed.Name
            // ...
        }
    })
    .FirstOrDefaultAsync();

var animal = await _context.Animals
    .Where(a => a.Id == id)
    .Select(a => new AnimalDto {
        Name = a.Name,
        // ...
        Breed = new BreedDto {
            Name = a.Breed.Name
            // ...
        }
    })
    .FirstOrDefaultAsync();

Also, reconsider using repositories altogether From what I see, your repository doesn't do anything EF wouldn't already be doing

TotechsStrypperOP•3y ago

on the method that use return CreatedAtAction ? or the FindById ?

Angius•3y ago

Where do you fetch the animal from the database? There

TotechsStrypperOP•3y ago

findbyid let me give you the full code

Angius•3y ago

My answer stays the same Wherever you fetch the animal and need its breed, you need to .Include() or .Select() it

TotechsStrypperOP•3y ago

        [HttpGet("{animalId}")]
        public async Task<IActionResult> GetById(int animalId, CancellationToken cancellationToken = default)
        {
            var animal = await _animalRepository.FindByIdAsync(animalId, cancellationToken);
            return animal != null ? Ok(_mapper.Map<AnimalDTO>(animal)) : NotFound("Unable to find the requested animal"); 
        }

        [HttpGet("{animalId}")]
        public async Task<IActionResult> GetById(int animalId, CancellationToken cancellationToken = default)
        {
            var animal = await _animalRepository.FindByIdAsync(animalId, cancellationToken);
            return animal != null ? Ok(_mapper.Map<AnimalDTO>(animal)) : NotFound("Unable to find the requested animal"); 
        }

cs

cs

but FindByIdAsync does include the Breed

TotechsStrypperOP•3y ago

TotechsStrypperOP•3y ago

And when call directly to it do give me the breed

Angius•3y ago

Maybe your mapper doesn't map it, then

TotechsStrypperOP•3y ago

The problem is why other method use return CreatedAtAction(nameof(GetById), new { Id = animal.Id }, _mapper.Map<AnimalDTO>(animal)); doesn't include the breed

Angius•3y ago

Dunno, I loathe the repository pattern and I don't use the automapper What's the full method that returns it? Seems to me like this animal might not have the breed included

TotechsStrypperOP•3y ago

Hope you can read it

        [HttpPost]
        public async Task<IActionResult> Create([FromBody] CreatePetDTO dto, CancellationToken cancellationToken = default)
        {
            var listOfOwnersGuid = dto.OwnerGuids.Split(',').ToList();
            var listOfOwner = new List<User>();
            foreach (var ownerGuid in listOfOwnersGuid)
            {
                var user = await _userRepository.FindByGuidAsync(ownerGuid, cancellationToken);
                if (user == null) return NotFound($"Cant find user with Guid: {ownerGuid}");
                else listOfOwner.Add(user);
            }
            using var petaverseTransaction = await _petaverseDbContext.Database.BeginTransactionAsync();
            var animal = _mapper.Map<Animal>(dto);
            var breed = await _breedRepository.FindByIdIQueryable(dto.BreedId, cancellationToken).FirstOrDefaultAsync();

            if(breed != null)
            {
                animal.SixDigitCode = await _animalRepository.Generate6DigitCodeAsync();
                animal.BreedId = breed.Id;
                _animalRepository.Add(animal);
                await _animalRepository.SaveChangesAsync(cancellationToken);
            }

            if(listOfOwner.Count > 0)
            {
                listOfOwner.ForEach(owner => _userAnimalRepository.Add(new UserAnimal() { UserId = owner.Id, AnimalId = animal.Id}));
                await _userAnimalRepository.SaveChangesAsync(cancellationToken);
            }

            await petaverseTransaction.CommitAsync(cancellationToken);
            return CreatedAtAction(nameof(GetById), new { animalId = animal.Id }, _mapper.Map<AnimalDTO>(animal));
        }

        [HttpPost]
        public async Task<IActionResult> Create([FromBody] CreatePetDTO dto, CancellationToken cancellationToken = default)
        {
            var listOfOwnersGuid = dto.OwnerGuids.Split(',').ToList();
            var listOfOwner = new List<User>();
            foreach (var ownerGuid in listOfOwnersGuid)
            {
                var user = await _userRepository.FindByGuidAsync(ownerGuid, cancellationToken);
                if (user == null) return NotFound($"Cant find user with Guid: {ownerGuid}");
                else listOfOwner.Add(user);
            }
            using var petaverseTransaction = await _petaverseDbContext.Database.BeginTransactionAsync();
            var animal = _mapper.Map<Animal>(dto);
            var breed = await _breedRepository.FindByIdIQueryable(dto.BreedId, cancellationToken).FirstOrDefaultAsync();

            if(breed != null)
            {
                animal.SixDigitCode = await _animalRepository.Generate6DigitCodeAsync();
                animal.BreedId = breed.Id;
                _animalRepository.Add(animal);
                await _animalRepository.SaveChangesAsync(cancellationToken);
            }

            if(listOfOwner.Count > 0)
            {
                listOfOwner.ForEach(owner => _userAnimalRepository.Add(new UserAnimal() { UserId = owner.Id, AnimalId = animal.Id}));
                await _userAnimalRepository.SaveChangesAsync(cancellationToken);
            }

            await petaverseTransaction.CommitAsync(cancellationToken);
            return CreatedAtAction(nameof(GetById), new { animalId = animal.Id }, _mapper.Map<AnimalDTO>(animal));
        }

it's ugly I know I trying to get better in writing cleaner code

Angius•3y ago

You seem to be setting the BreedId of the animal not the Breed of it?

TotechsStrypperOP•3y ago

They both return

_mapper.Map<AnimalDTO>(animal)

_mapper.Map<AnimalDTO>(animal)

Angius•3y ago

animal.BreedId = breed.Id; Yeah, but you use different ways to get that animal there In the first method you use a repository, in the second you use some other demented repository-thing After the animal.BreedId = breed.Id; line add animal.Breed = breed See if that helps

TotechsStrypperOP•3y ago

Okay I will put that after the SaveChanges()

Angius•3y ago

Maybe? Idk Repositories are a mess

TotechsStrypperOP•3y ago

because EF will create another breed if put it before the savechange

Angius•3y ago

Fuck repositories All my homies hate repositories

TotechsStrypperOP•3y ago

what's your pattern ? can you link me the blog or docs to implment your style ?

Angius•3y ago

CQRS and services where needed

TotechsStrypperOP•3y ago

services ...

Angius•3y ago

Yes Instead of duplicating the functionality that DbSet already gives you for free, you create specific methods

TotechsStrypperOP•3y ago

do you have a simple project repo ?

Angius•3y ago

Afraid not

TotechsStrypperOP•3y ago

cqrs heard that many but never understand it

Angius•3y ago

But the idea is that instead of

public class ThingRepository
{
    // ...
    public async Task<Thing> Find(int id)
        => await _context.Things.FindAsync(id);
}

public class ThingRepository
{
    // ...
    public async Task<Thing> Find(int id)
        => await _context.Things.FindAsync(id);
}

which is just a useless abstraction over EF, you do

public class ThingService
{
    // ...
    public async Task<ThingCard> GetThingCardById(int id)
        => await _context.Things
            .Where(t => t.Id == id)
            .Where( ... )
            .Select(t => new ThingCard { ... })
            .FirstOrDefaultAsync();
}

public class ThingService
{
    // ...
    public async Task<ThingCard> GetThingCardById(int id)
        => await _context.Things
            .Where(t => t.Id == id)
            .Where( ... )
            .Select(t => new ThingCard { ... })
            .FirstOrDefaultAsync();
}

etc The idea behind services

TotechsStrypperOP•3y ago

is Unit Of Work also a service ?

TotechsStrypperOP•3y ago

woah you totally right

Angius•3y ago

EF already implements UoW

TotechsStrypperOP•3y ago

aww man CreateAtAction suck I thought it just route the action and all the behavior stay the same

Angius•3y ago

Nope, it doesn't call the actual action Just constructs the URL and returns some data

TotechsStrypperOP•3y ago

but aint it suppose to do the same ? just pass the parameter call the right route and define what it need to to return ? If have some additional logic inside GetById. It will not work ?

Angius•3y ago

¯\_(ツ)_/¯ Here's a CQRS sample from one of my projects: https://github.com/Atulin/CQRS-Sample Press the . key when you open the repo in the browser so you can browse the code more easily

TotechsStrypperOP•3y ago

did you just create a freaking repo for like 5 minutes ?

Angius•3y ago

Yeah, why? git init && git add . && git commit -am "init" already gets you halfway there lol

TotechsStrypperOP•3y ago

you re freaking beast

Angius•3y ago

Ah, the BaseHandler might be a bit confusing, but all it is is just provides some shims to handle returns types easier. It's just a bunch of

    public OkResult Ok() => new();
    public OkObjectResult Ok(object o) => new(o);

    public OkResult Ok() => new();
    public OkObjectResult Ok(object o) => new(o);

methods

TotechsStrypperOP•3y ago

you mean the return CreatedAtAction(nameof(GetById), new { Id = animal.Id }, _mapper.Map<AnimalDTO>(animal)); ?

Angius•3y ago

Nope, in the example code I sent you All the Handler classes inherit from BaseHandler that isn't a standard MediatR class, thought I'll clarify

TotechsStrypperOP•3y ago

okay let me see Mediator is that cqrs thingy ?

Angius•3y ago

It's a library that makes CQRS easier Very commonly used. In fact, I don't know anybody who wouldn't use it for CQRS lol

TotechsStrypperOP•3y ago

ohhhhhhhhhhhhhhh I see now say thanks for helping me all these time can I have friend request ?

Angius•3y ago

You can ping me if you need help

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Object null when using the same action controller

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