hotchocolate custom filter on parent based on child collection

Question

I'm trying to implement similar to described here filtering model with hotchocolate code-first approach. I need to filter movies if at least one of their actors meets certain criteria. Model looks like this:

public class Movie
{
    public IList<Actor> Actors { get; set; }
}

public class Actor { }

public class MovieTypeDef : ObjectType<Movie>
{
    protected override void Configure(IObjectTypeDescriptor<Movie> descriptor)
    {
        descriptor.Field(x => x.Actors)
            .Type<NonNullType<ListType<NonNullType<ActorTypeDef>>>>();
    }
}

public class ActorTypeDef : ObjectType<Actor> { }

public class Query
{
    public IList<Movie> Movies()
    {
        return new List<Movie>();
    }
}

public class QueryTypeDef : ObjectType<Query>
{
    protected override void Configure(IObjectTypeDescriptor<Query> descriptor)
    {
        descriptor.Field(x => x.Movies())
            .Type<NonNullType<ListType<MovieTypeDef>>>()
            .UseFiltering<MoviesFileringTypeDef>();
    }
}

public class MoviesFileringTypeDef : FilterInputType<Movie>
{
    protected override void Configure(IFilterInputTypeDescriptor<Movie> descriptor)
    {
        descriptor.Filter(x => x.Actors) // compilation error
    }
}

There seems to be no ability to add custom filter to MoviesFileringTypeDef since it only allows using properties of Movie class, and collections are not accepted there. Is it possible to implement such filter with hotchocolate?

If you implement a custom query rewriter it should be possible. — Michael Ingmar Staib, Mar 30 '20 at 22:09
Is there any update on this one? I am running into similar scenario. It would be helpful if there is a way to tackle this. — Mahesh Nepal, May 26 '21 at 13:47

score 1 · Answer 1 · edited Dec 13 '22 at 19:55

I also faced a similar kind of issue while I was trying to apply a filter on the parent entity based on the child entity field. I believe in your case you need to apply a filter in your MovieTypeDef also with QueryType as below:

public class MovieTypeDef : ObjectType<Movie>
{
    protected override void Configure(IObjectTypeDescriptor<Movie> descriptor)
    {
        descriptor.Field(x => x.Actors)
            .Type<NonNullType<ListType<NonNullType<ActorTypeDef>>>>()
            .UseFiltering<YourModel>();
    }
}

After this change, you can apply a filter on a nested level also as you can apply with the parent level.

hotchocolate custom filter on parent based on child collection

1 Answers1