:wave: Trying to wrap my head around normalized ca...

# apollo-kotlin

[David Albers]

👋 Trying to wrap my head around normalized cache and looking for some help:
I have a query like

query Accounts($filter: Filter) {
    accounts(filter: $filter) {
     id
     type 
     name
   } 
}

where the parameter is a filter and it’s optional. If no filter is given, you get an unfiltered list.

The main screen in my app requests this data with filter: null so it can get all the accounts. A detail screen requests the data with filter: {type: OPEN} .

I’m seeing a cache miss when I go to the detail screen. Is there a way for the detail screen to get cached data from the main screen even though the params are different?

[David Albers]

I have a CacheKey setup to use the id: CacheKey("Account:${obj["type"]}:${obj["id"]}") . I assume there’s something there I need to change but I’m not sure what.

[bod]

Hi! If you give it a different filter, the returned value would usually be different, so you can't really use the cached value, right?

[David Albers]

hmm, that’s a good point. I guess there’s no way for Apollo to “know” how to filter the data.

[bod]

exactly 🙂

[mbonnin]

You could do something using the low-level CacheResolver API

[mbonnin]

It's going to involve a fair amount of non-trivial code but if you know that filter: null is always the same as filter: {type: OPEN} , you could handle that programmatically

[mbonnin]

The default resolveField is doing something like this:

val name = field.nameWithArguments(variables)
    if (!parent.containsKey(name)) {
      throw CacheMissException(parentId, name)
    }

    return parent[name]
  }

So if you can make it so that name above becomes accounts(filter: null) whenever {type: OPEN} is passed, data will be looked up from the parent record