Question about the http4k-graphql module: I’m look...

# http4k

[Arnab Datta]

Question about the http4k-graphql module:
I’m looking at the example that is given in the examples repo, and I’m testing the following query against `localhost:8000/graphql/user`:

{
  search(params: {ids: [1,2]}){
    id
    name 
  }
  s2:search(params: {ids: [1,2]}){
    id
    name 
  }
}

and using a small .also { println("running some expensive query") } I was able to see that this was calling the UserQueries.search method twice. Since the example specifically has a dataloader, I was wondering why? Isn’t the whole point of dataloaders that regardless of how the query is formed, one only calls the underlying service just once? Or is this specific to nested queries only (i.e. calls to fields of type User say for instance a friends field that invokes some kind of function towards the DB)? What am I misunderstanding here?

[dave]

TBH, the example is a very naive one used to show how to integrate the module. If it can be improved (whist also remaining clear) then we've love to know how!

[Arnab Datta]

I think what I’m struggling to understand is whether or not the dataloader is actually being used. It seems that it isn’t.

[Arnab Datta]

I used the following to verify (in the UserDbHandler class):

UserQueries().search(Params(ids)).also { println("some expensive db function") }

[Arnab Datta]

It never prints that line

[Arnab Datta]

That to me suggests that the dataloader is not actually used by the graphql engine