Inventory copying

[Pokémaniac]

Asdfghjkl I should be able to do this by now, but I can't(I've been editting scripts all day, to absolutely no success :|).

Basically, I want to be able to store a copy of the player's inventory at a point in time, then change the player's inventory to the stored version at a later point in time. So far, my messing around has got me to these 2 snippets;

in one common event

item = $game_party.items

$inventory = item

and in another common event

item = $inventory

$game_party.items = item

However, when I run this, the next time anything happens involving $game_party.items, the game crashes with the error "Script Game_Party line 52: NoMethod Error / undefined method "keys" for array blahblahblah"
I can't work out how to do this. Help please?

 

[Brewmeister]

try:

$inventory = {}
$inventory = $game_party.items.dup

then

$game_party.items = $inventory

You need to declare $inventory as a 'hash' before using it.

 

[Pokémaniac]

I don't have a chance to try it out now, but it sounds right anyway. Thanks!

(also I haven't heard of the .dup method. What does it do? It looks like it makes a copy(which would make sense), but how is it different to just going x=y ?

 

[Pokémaniac]

O-oh dear.

Okay, I tried it out. When I use it, it doesn't throw any errors until "$game_party.items = $inventory", when it throws out
"undefined method: "Keys" for #<arrayblahblahblah>"

Now, I got it to print the value of both $inventory and $game_party.items and they were identical. What's going on?

I also tried it in a game with default scripts, and got a different error, on the same line;
"Undefined method : "items=" for #<Game_Partyblahblahblah>"

Help?

 

[Ares]

Before you can modify $game_party.items, you need permission to alter it. You can get that permission by adding the following in Game Party after line 14:
[rgss]attr_accessor :items
[/rgss]

Then you can do:
[rgss] 
$inventory = $game_party.items.dup # creates $inventory which is a copy of $game_party.items
$game_party.items.clear # clears the inventory
$game_party.items = $inventory # restores the inventory; $inventory is actually some kind of back up
[/rgss]

Hope that solves your problem

edit:
'dup' is a method of the Array and Hash classes, and does almost the same as 'clone'. This is the definition from the help file:

Returns a new hash with the same contents as the receiver. Using clone on a frozen hash will return a similarly frozen hash, but dup returns an unfrozen hash with identical contents.

Returns a new array with the same contents as the receiver. clone returns a complete clone of the original array, including freeze status and singleton methods, while dup duplicates the object contents only. Neither method copies the methods or elements themselves.

You can also use "$inventory=$game_party.items", but I personally don't like that syntax very much.

 

[Pokémaniac]

Thanks for the explanation of .dup, Ares, but attr accessor: items is already in game_party. I tried your method, but I still get the same error.

 

[Pokémaniac]

Actually, now I look at my default-scripts project, that line of code isn't there by default. Unfortunately, adding it to the default project just causes me to get the same error as in the project with scripts.

Also, there's one difference; I still get the same crash error, but now I don't get it until I try to start a battle. It's just that both versions have a battle right after the script call, so I didin't notice at first.

 

[Ares]

Hmmm, I can't recreate that error :huh:
Can you post the events you are using? Also, are you using any other scripts?

"Undefined method : "Keys" for #<arrayblahblahblah>"

This error seems to indicate that you are trying to obtain an array of the keys (@blah.keys) of an array, which throws an error because keys is not a method in the 'Array' class. So most likely $game_party.items or $inventory is an array instead of a hash. In just a blank project it works fine for me, even when starting a battle.

I hope I can help you solve this soon because I am going to Austria for a week this evening (in about 4 hours).

 

[Gubid]

Yeah, gonna need to see the code used to produce the error if we are to be helpful.

 

[Pokémaniac]

asdfghjkl I think I know what's going on(kinda)

I just tried your script, and got it to work. The problem is, I'm an idiot, and I forgot to mention I'm working in VX. Sorry for messing you guys around like that.

Problem is, I still don't know what to change to make it compatible. The code I'm using is just an event that adds an item to the inventory, then calls the copy/erase/replace script that Ares made(who unfortunately must've fled the country by now). Still, hopefully this will help.

 

[Pokémaniac]

Hey guys, I still need help with this.

 

[Gubid]

Please post the code you are running that is failing. We will not be able to help you without seeing it.

 

[Pokémaniac]

Sure.

with attr_accessor :items added as line 16 of Game Party.


This gives the the "keys" error I talked about before every time something happens involving items.

 

[Brewmeister]

did you declare $inventory anywhere?

$inventory = {}

Interesting that the assignment seems to cast it as an array instead of a hash????

 

[Yeyinde]

The casting from hash to array is because Game_Party#items is not a reader of @items, but a method that returns an array of RPG::Item, RPG::Weapon, and RPG::Armor objects.

 

[Brewmeister]

It is entirely conceivable that I'm an idiot & completely overlooked that... :scruff:

 

[Gubid]

You could just have it return an instance_eval of @items. ($game_party.instance_eval("@items"), I will try this later and let you know if it works.

 

[Pokémaniac]

"Bump". Sorry, it's just I think this is getting closer to being resolved and I really do need this snippet!