How to Get a Fauna Value's Ref in Go

The FaunaDB docs are pretty thorough, but I've noticed that every example of querying an object by ref assumes you already have the ref ID handy.

Take, for instance, this Update example in Go:

result, _ := client.Query(
  f.Update(
      f.RefCollection(f.Collection("spells"), "181388642581742080"),
      f.Obj{
          "data": f.Obj{"name": "Mountain's Thunder", "cost": nil}}))

if (err != nil) {
  fmt.Println(err)
} else {
  fmt.Println(result)
}

The ref ID 181388642581742080 is hard-coded! But what if you don't just have a handy map of all the refs in your collection??

Don't worry, I gotchu. Go's typing system makes the process a little additionally verbose, but it's reliable.

import (
    f "github.com/fauna/faunadb-go/v3/faunadb"
)

// setup code

client := f.NewFaunaClient("YOUR_CLIENT_KEY")

ref, err := client.Query(f.Get(f.MatchTerm(f.Index("ANY_INDEX_YOURE_USING"), theSearchValue)))
if err != nil {
    // handle error
}

var refAssert *f.RefV
if err = ref.At(f.ObjKey("ref")).Get(&refAssert); err != nil {
    // handle error
}

// the rest

The key piece is running ref.At().Get(&refAssert), where refAssert is of type *f.RefV. This accurately maps to the response value you get from your query and should allow you to use refAssert.ID for any future queries.

Enjoy!