question

Yeah I read the tutorial a couple of times. I guess I'm confused on how to actually call the UpdateUserInventoryItemCustomData function in the handler i created. Also how to add parameters for the function as well.

We have a few examples of making calls in the Server API in our Cloud Script samples: https://github.com/PlayFab/CloudScriptSamples.

So the call to use UpdateUserInventoryItemCustomData might look something like this:

var serverData = server.UpdateUserInventoryItemCustomData ({
"PlayFabId": currentPlayerId,
"ItemInstanceId": args.instanceToUpdate,
"Data": dataObj
});

Where the data payload would be created as shown in this post: https://community.playfab.com/hc/en-us/community/posts/205460148-Cloud-Script-how-do-I-write-data-to-a-Key-which-is-defined-dynamically

Okay, just getting confused on the data part. The data would change depending on what item the character obtained or moved. For an example, the character looted a monster and got an item "Shirt". "Shirt" has a custom data on it called "Armor" with a value of 5. When the client tries to get that value in Armor it gives an error which you help me understand that the value wasn't there and said I should use the server function to do so. So I would create the data by saying

var dataObj = ["Armor", "5"];

But what happens if they obtained "Shirt 2" which has an "Armor" value of 10?

First, you'll run into an issue with it defined that way. Since you'll probably need to have a variety of Keys for the data you're setting up, I would encourage using the script the way shown in the linked post, above:

    var keyString = "foo";
    var dataPayload = {};
    dataPayload[keyString] = "bar";

That way, you can set the Key to whatever you need programatically.

So, for your example, you would decide what values you want to set, and to what keys, based on your custom game logic. So, if ItemId "Shirt" should always be 5 and "Shirt2" should always be 10, you would set them that way. But if the items always have the same value, I would recommend just using the CustomData at the Catalog level, so that you can change it later and have that apply to all players. The item instance CustomData is really intended for data which is going to be unique to that instance - like for procedurally generated items, or items that "wear out" over time.

So things like Armor, Power, etc should be used on the custom data? But things like position in a bag I shouldn't be using it for. How should I go about doing the position of the item in the inventory then? How could I get the custom data for a tooltip or to increase stats on the character?

To be clear, what I'm saying is that a value which should be the same for all instances of an ItemId, that value should be defined at the Catalog level, so that you can adjust it there if needed, and have that be picked up and used by all clients. For any value which is unique to the specific item instance, that should be stored in the Custom Data of the item instance itself.

So, the position of an item for an individual player is clearly unique to that player, and so should be stored on the item instance. For armor and power, it depends - is that value unique to that player's instance, or is it the same as all other instances of the item in the game (in which case you should store that data at the Catalog level)?

Tooltips are usually global, so again, I would recommend storing that (or a lookup value, if you have a separate localization file) in the Catalog.

For increasing statistics on a player (or character), presumably you mean due to having the item equipped? Again, is the value in question the same for all instances, or is it unique to the player's instance of the item? That's really the only deciding factor.

Things like armor and power would be the same for all instances and the only thing that would change from player to player would be the position of the item. So my question is how do I get the custom data in either instance?

The CustomData at the Catalog level is in the CatalogItem returned from a call to https://api.playfab.com/Documentation/Client/method/GetCatalogItems.

For item instances, it's in the ItemInstance info returned from any inventory retrieval call, like https://api.playfab.com/Documentation/Client/method/GetUserInventory.

You set the CustomData in the Catalog via https://api.playfab.com/Documentation/Admin/method/SetCatalogItems or https://api.playfab.com/Documentation/Admin/method/UpdateCatalogItems.

And you can set the CustomData in the player's item instance in Cloud Script with https://api.playfab.com/Documentation/Server/method/UpdateUserInventoryItemCustomData.