How to filter on sub-property?

[judgeaxl]

Hi! I've got a JSON:API which supports querying on a property in a nested list:

class Child {
  property
}

class Parent {
  children: Child[]
}

I would like to write a filter clause on children.property == value, bscially getting all Parents who has a child matching the property. The API does not expose the Child collection directly, they are only available through /parents.

Essentially, is it possible to write a FilterClause which doesn't use the root type of the entity store?

I eventually need the filter query to look like /parents?filter[property]=value

Thanks!

[dpimonov]

Hi judgeaxl,

Yes, it's possible to filter on sub-property, but not on a collection. For example, given the following classes:

class Child {
  property: string;
  parent: Parent;
}

class Parent {
  property: string;
  children: Child[];
}

You can write something like this:

childSet.filter((child, f) => f.eq(child.parent.property, value));

However, collection drill-down is not yet supported.

[judgeaxl]

OK, thanks. I came up with a hack, adding a non-array property without serialization, using a prefix I can detect in my filter visitor, so I can move on for now. Only had one instance where I needed this in the whole API.

e.g.

class Parent {
  property: string;
  children: Child[];
  _filter: Child;
}