Retrieve child entities from CrudAppService in ABP

Question

The GetAll and Get methods of the ready-made CrudAppService don't include child entities.

Is it possible to modify its behaviour?

Update

GetAllIncluding has some problem if the included entity has a navigation property to the parent; it falls into a sort of circular dependency. Is there any Attribute or trick to exclude the navigation property from the serialization? The [NonSerialized] attribute does not seem to be applicable to a navigation property.

PostAppService:

public class PostAppService : CrudAppService<Post, PostDto>, IPostAppService
{
    IRepository<Post> _repository = null;

    public PostAppService(IRepository<Post> repository) : base(repository)
    {
        _repository = repository;
    }

    protected override IQueryable<Post> CreateFilteredQuery(PagedAndSortedResultRequestDto input)
    {
        return _repository.GetAllIncluding(p => p.Items);
    }
}

PostDto:

[AutoMap(typeof(Post))]
public class PostDto : EntityDto
{
    public ICollection<Item> Items { get; set; }
}

Post entity:

[Table("AbpPosts")]
public class Post : FullAuditedEntity<int,User>
{
    public virtual ICollection<Item> Items { get; set; }
}

Item entity:

[Table("AbpItems")]
public class Item : Entity
{
    [ForeignKey("PostId")]
    public Post Post { get; set; }
    public int PostId { get; set; }
}

aaron · Accepted Answer · 2018-01-23T17:00:01.520

You have to use eager-loading.

Override CreateFilteredQuery and GetEntityById in your AppService:

public class MyAppService : CrudAppService<ParentEntity, ParentEntityDto>, IMyAppService
{
    public MyAppService(IRepository<ParentEntity> repository)
        : base(repository)
    {
    }

    protected override IQueryable<ParentEntity> CreateFilteredQuery(PagedAndSortedResultRequestDto input)
    {
        return Repository.GetAllIncluding(p => p.ChildEntity);
    }

    protected override ParentEntity GetEntityById(int id)
    {
        var entity = Repository.GetAllIncluding(p => p.ChildEntity).FirstOrDefault(p => p.Id == id);
        if (entity == null)
        {
            throw new EntityNotFoundException(typeof(ParentEntity), id);
        }

        return entity;
    }
}

The benefit of overriding these methods is that you continue to get permission checking, counting, sorting, paging and mapping for free.

Update

GetAllIncluding has some problem if the included entity has a navigation property to the parent; it falls into a sort of circular dependency. Is there any Attribute or trick to exclude the navigation property from the serialization?

Return ItemDto (without navigation property) in PostDto.

score 2 · Answer 2 · answered Jan 23 '18 at 14:11

2

Yes, You have to include explicitly like this.

GetAll().Include(i => i.ChildEntities)

answered Jan 23 '18 at 14:11

Vivek Nuna

25,472
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score 1 · Answer 3 · answered Jan 23 '18 at 13:59

1

You have to include the child entities manually. It's lazy loading by design.

answered Jan 23 '18 at 13:59

Alper Ebicoglu

8,884
1
49
55

do you mean create a method (e.g. myGet) that use directly the repository invoking entityframwork include comand? `var events = await _eventRepository .GetAll() .Include(e => e.Registrations) .WhereIf(!input.IncludeCanceledEvents, e => !e.IsCancelled) .OrderByDescending(e => e.CreationTime) .ToListAsync();` – pinale Jan 23 '18 at 14:11
yeah @alex . that's exactly what I mean – Alper Ebicoglu Jan 23 '18 at 14:14
I did not get why both async and non-async version of CrudService exists. It also confuses me, that non-async versions method are called -Async, deal with Task - so they are kind of "async-ready". So when I am supposed to use one and when another? @vivek-nuna could you please also advice? – Alexander May 29 '20 at 14:21

score 0 · Answer 4 · answered Apr 10 '20 at 14:35

0

For whom that work with AsyncCrudAppService and you have two different lists of child:

Below to get specific parent Object with their list of child

 protected override Task<Parent> GetEntityByIdAsync(int id)
        {
            var entity = Repository.GetAllIncluding(p => p.listOfFirstChild).Include(x => x.listOfSecondChild).FirstOrDefault(p => p.Id == id);
            return base.GetEntityByIdAsync(id);
        }

answered Apr 10 '20 at 14:35

Abdulaziz

654
3
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Seems like you have mixed two approaches together :) You don't use entity anywhere. – Alexander May 26 '20 at 12:15

score 0 · Answer 5 · answered Jul 15 '20 at 11:25

In Abp.io All You Need Is (that must be added to PostService inherited from CrudAppService ):

 protected override IQueryable<Post> CreateFilteredQuery(PagedAndSortedResultRequestDto input)
        {
            return _postReposiory
                 .Include(p => p.Item);
        }

Retrieve child entities from CrudAppService in ABP

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