Understanding Storage Usage

Game Design
1

Hello everybody!

Im starting working with Nakama and currently trying to understand some things.

Im using Lua for language, and trying to get some stuff working.

In the API explorer I seems to not being able to store objects with a non empty value

{
  "objects": [
    {
      "collection": "inventory",
      "key": "weapons",
      "value": "{}",
      "version": "",
      "permissionRead": 1,
      "permissionWrite": 1
    }
  ]
}

I did tryied to put anything in value and I always got the rpc error: code = InvalidArgument desc = Value must be a JSON object., the only way im not getting that error its while using empty value which is ofc not how to use the storage engine

Same happens if I try to run a similar code from my inventory.lua script.

Full code here.

local nk = require("nakama")
nk.logger_info("Economy module loaded")

function EditInventory_rpc(context, payload)
    nk.logger_info("Inventory Manager Loaded")
    
    local version = nil
    
    local new_objects = {
        { collection = "inventory", key = "weapons", user_id = "00000000-0000-0000-0000-000000000000", value = {}, version = "", permission_read = 1, permission_write = 1 }
      }

    nk.storage_write(new_objects)
end

Where am I failing? What is expected to be inside of version? Can someone show me a complete example of a storage write with version filled up?

Edit: Im also having an “Error whilst making RPC call: SyntaxError: Unexpected end of JSON input” in the API Explorer using my custom function, but it stills write to the inventory. Why is that?

2

If someone its having this same issue, here is what I did in order to fix it.

local nk = require("nakama")
nk.logger_info("Economy module loaded")

function EditInventory_rpc(context, payload)
    nk.logger_info("Inventory Manager Loaded")
    
    local version = nil
    
    local table = {}
    table["name"]="Angel Slayer"
    table["weaponType"]="Dagger"
        
    local new_objects = {
        { collection = "inventory", key = "weapons", user_id = "00000000-0000-0000-0000-000000000000", value = table, version = "*", permission_read = 1, permission_write = 1 }
      }

    nk.storage_write(new_objects)
    return nk.json_encode({["success"] = true})
end

So, the error I was getting was that I missed the return nk.json_encode({["success"] = true}) thing at the end. So remember to check this if something like this happens haha.

also, the value content must be a Lua table as described in this documentation.

While its a basic thing, I guess that im not the only one that at least once faced this issue, so I upload this here.

3 Likes
3

thank you that helped!

4

Hello,
Thanks for the solution, this is very informative.