Graphql-ruby: Get requested fields in resolve

[jsnick]

Can I get requested fields in resolve ?
I want to use includes, ActiveRecord::QueryMethods selectively.

[cpunion]

Found a way:

resolve -> (_, _, ctx) {
  ctx.selection.scoped_children.values[0].keys
}

Maybe it's different for your query.

I'm not sure if it is long supported, it used GraphQL::InternalRepresentation::Node#scoped_children.

[rmosolgo]

You can access child selections with

ctx.irep_node.typed_children 

It returns Hash<ObjectType => Hash<String => InternalRepresentation::Node> where:

• ObjectType is the runtime type of the return values (for fields that return union or interface types, there may be _multiple_ object types as keys)
• String is the name in the _result_ (so, alias _or_ field name)
• InternalRepresentation::Node is the representation of the child selection. It has .definition to access the GraphQL::Field and .definition_name to access the name of that field.

Sorry the API is a bit ... all of the place. I haven't solidified it much because I haven't _had_ to. If you want to share your use case, I'd be happy to consider some improvements! Hope that helps.

[jsnick]

Thank you !

For minimizing the number of queries in my app, I usually use includes (ActiveRecord::QueryMethods) which pre-fetchs included rows associated.

I'll just check requested fields and if the associated rows in another table exists, then add it to includes methods.
But if don't need associated rows, I don't have to include that.

[rmosolgo]

Great!

[mengqing]

Is there a better API now or is this still the only way to check it?

[rmosolgo]

no better api yet!