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Item types

https://forums.factorio.com/viewtopic.php?t=53231

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Item types

Posted: Sun Oct 08, 2017 11:50 am
by darkfrei
Hi all,

why are we have a lot of item types?

I've made some table:

Code: Select all

 item_type_list = {
  "ammo",
  "armor",
  "gun",
  "item",
  "capsule",
  "repair-tool",
  "mining-tool",
  "item-with-entity-data",
  "rail-planner",
  "tool",
  "blueprint",
  "deconstruction-item",
  "blueprint-book",
  "selection-tool",
  "item-with-tags",
  "item-with-label",
  "item-with-inventory",
  "module"
}
or this item can be called as

Code: Select all

local item = 
	data.raw.item[result_name] 
	or data.raw["item-with-entity-data"][result_name] 
	or data.raw["mining-tool"][result_name] 
	or data.raw["gun"][result_name] 
	or data.raw["ammo"][result_name] 
	or data.raw["armor"][result_name] 
	or data.raw["repair-tool"][result_name] 
	or data.raw["mining-tool"][result_name] 
	or data.raw["capsule"][result_name] 
	or data.raw["fluid"][result_name] 
	or data.raw["module"][result_name] 
	or data.raw["rail-planner"][result_name] 
	or data.raw["tool"][result_name] 
	or data.raw["blueprint"][result_name] 
	or data.raw["deconstruction-item"][result_name] 
	or data.raw["blueprint-book"][result_name] 
	or data.raw["selection-tool"][result_name] 
	or data.raw["item-with-tags"][result_name] 
	or data.raw["item-with-label"][result_name] 
	or data.raw["item-with-inventory"][result_name]
and now you can change, for example, item.stack_size

It's looks a little bit too complicated.

Re: Item types

Posted: Sun Oct 08, 2017 12:06 pm
by Bilka
darkfrei wrote:Hi all,

why are we have a lot of item types?
Because they each have their own specific function. You don't need iron plates to be able to have the ability to have a durability or an inventory, that would only add to the save file size and also decrease performance. So they are of a type that can't have those attributes. Here is an overview of the item types which shows what item types inherit properties from where:
Item.png
Item.png (32.26 KiB) Viewed 4708 times
darkfrei wrote: It's looks a little bit too complicated.
How is that complicated? There are a lot of types, but whenever they share attributes, those attributes are of the same format. Maybe it's annoying for the average mod author, but it's definitely not complicated to just iterate through all possible types.

Fluids aren't items btw

Re: Item types

Posted: Sun Oct 08, 2017 12:15 pm
by darkfrei
Bilka wrote:Fluids aren't items btw
Thanks for your answer.

It was a part of function, where item was called from recipe result for checking that compared item_stack_size and result_amount.

Code: Select all

if result_amount > item.stack_size then
	item.stack_size = result_amount
end
And liquids will be ignored.

Re: Item types

Posted: Mon Oct 09, 2017 1:12 am
by eradicator
If you already have a list of possible item types why not just iterate through it instead of that "or or or" block?

Code: Select all

local item_type_list = ... --as in opening post

local function get_item_prototype(item_name)
  for _,typ in pairs(item_type_list) do
    local prot = data.raw[typ][item_name]
    if prot then return prot end
    end
  end
  
local item = get_item_prototype(result_name)

Re: Item types

Posted: Mon Oct 09, 2017 9:29 am
by bobingabout
I suppose the most confusing thing about multiple item types is that when you want to access the item type, you need to use the extra info.

data.raw.tool["science-pack-1"].icon

Yet when you want to add it to a recipe, you only explicitly use item or fluid

{type = "item", name = "science-pack-1", amount = 1}

Re: Item types

Posted: Mon Oct 09, 2017 8:55 pm
by eradicator
bobingabout wrote:I suppose the most confusing thing about multiple item types is that when you want to access the item type, you need to use the extra info.
I thought about this for "a bit" (and i'd better not say for how long) and i think i found an acceptable solution. Using the list of prototype types that the game internally treats as items (i.e enforces unique naming above, etc):

Code: Select all

item_types = { --index of prototype types that will be redirected to "item"
  "gun"    , "blueprint"     , "item-with-tags"        ,
  "ammo"   , "repair-tool"   , "item-with-label"       ,
  "tool"   , "mining-tool"   , "item-with-inventory"   ,
  "armor"  , "rail-planner"  , "item-with-entity-data" ,
  "module" , "blueprint-book", "deconstruction-item"   ,
  "capsule", "selection-tool"
}
We can then use the function i posted above and define it as an __index method for data.raw.item like this:

Code: Select all

local meta = getmetatable(data.raw.item) or {}
meta.__index = function(_,item_name)
  for _,typ in pairs(item_types) do
    local prot = data.raw[typ][item_name]
    if prot then return prot end
    end
  end
setmetatable(data.raw.item,meta)
The __index method is called every time we try to access data.raw.item with a key that doesn't exist, i.e. because it's of one of the other prototype types. It then searches through all the item_types and returns a pointer to the table of the item found. So we can now access all of the above types from data.raw.item:

Code: Select all

--any type listed in item_types can now be accessed like it was an "item"
data.raw.item['combat-shotgun'].attack_parameters.range = 60
print(data.raw.item["science-pack-1"].order)
Simply put above code at the start of your data.lua and it should work.

Re: Item types

Posted: Sat Oct 14, 2017 11:34 am
by darkfrei
So, this code makes item type table, example of result [0.15.35] is in the spoiler

Code: Select all

make_item_type_table ()
	local item_type_list = {"ammo","armor","gun","item","capsule","repair-tool","mining-tool","item-with-entity-data","rail-planner","tool","blueprint","deconstruction-item","blueprint-book","selection-tool","item-with-tags","item-with-label","item-with-inventory","module"}
	item_type_table = {}
		for i, item_type_name in pairs (item_type_list) do
			for item_name, item in pairs (data.raw[item_type_name]) do
				item_type_table[item_name] = item_type_name
			end
		end
	log ('item_type_table = ' .. serpent.block(item_type_table, {comment = false}))
end
item_type_table

Re: Item types

Posted: Sat Oct 14, 2017 12:18 pm
by eradicator
That fixed table approach will not work for any items created after you create the table. That is why my __index method looks up the prototype each time.
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