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| title | layout | root | idx | redirect_from |
|---|---|---|---|---|
| Inventories | default | ../.. | 5.2 | /en/chapters/inventories.html |
Introduction
In this chapter you will learn how to use and manipulate inventories, whether that is a player inventory, a node inventory, or a detached inventory. This chapter assumes that you already know how to create and manipulate ItemStacks.
Basic Concepts
Components of an inventory:
- An inventory is a collection of inventory lists, which are simply called lists in the context of inventories.
- An inventory list is an array of slots. (An array is a table indexed by numbers).
- A slot contains a stack which may or may not be empty.
- An InvRef is an object that represents an inventory, and has functions to manipulate it.
Types of Inventories
There are three types of inventory:
- Player Inventories: An inventory attached to a player.
- Node Inventories: An inventory attached to a node.
- Detached Inventories: An inventory which is not attached to a node or player.
The creative inventory, left (in red) is detached and is made up of a single list.
The player inventory, right (in blue) is a player inventory and is made up of three lists.
Note that the trash can is a formspec element, and is not part of the inventory.
Player Inventories
A player inventory usually has two grids, one for the main inventory and one for crafting. Press i in game to see your player inventory.
Use a player's name to get their inventory:
{% highlight lua %} local inv = minetest.get_inventory({type="player", name="celeron55"}) {% endhighlight %}
Node Inventories
A node inventory is related to the position of a specific node, such as a chest. The node must be loaded, because it is stored in node metadata.
Use its position to get a node inventory:
{% highlight lua %} local inv = minetest.get_inventory({type="node", pos={x=, y=, z=}}) {% endhighlight %}
Detached Inventories
A detached inventory is independent of players and nodes. One example of a detached inventory is the creative inventory. It is detached from any specific player because all players see the same creative inventory. A detached inventory would also allow multiple chests to share the same inventory.
Use the inventory name to get a detached inventory:
{% highlight lua %} local inv = minetest.get_inventory({type="detached", name="inventory_name"}) {% endhighlight %}
You can create your own detached inventories:
{% highlight lua %} minetest.create_detached_inventory("inventory_name", callbacks) {% endhighlight %}
This creates a detached inventory or, if the inventory already exists, it is cleared. You can also supply a [table of callbacks]({{ page.root }}/lua_api.html#detached-inventory-callbacks).
InvRef and Lists
Inventory Location
You can check where an inventory is located:
{% highlight lua %} local location = inv:get_location() {% endhighlight %}
This will return a table like the one passed to minetest.get_inventory().
If the location is unknown, {type="undefined"} is returned.
List Sizes
Inventory lists have a size, for example main has size of 32 slots by default.
They also have a width, which is used to divide them into a grid.
{% highlight lua %} if inv:set_size("main", 32) then inv:set_width("main", 8) print("size: " .. inv.get_size("main")) print("width: " .. inv:get_width("main")) else print("Error!") end {% endhighlight %}
Empty Lists
You can use list_is_empty to check if a list is empty:
{% highlight lua %} if inv:is_empty("main") then print("The list is empty!") end {% endhighlight %}
Lua Tables
You can convert an inventory to a Lua table:
{% highlight lua %} local lists = inv:get_lists() {% endhighlight %}
The table will be in this form:
{% highlight lua %} { list_one = { ItemStack, ItemStack, ItemStack, ItemStack, -- inv:get_size("list_one") elements }, list_two = { ItemStack, ItemStack, ItemStack, ItemStack, -- inv:get_size("list_two") elements } } {% endhighlight %}
You can then set the inventory:
{% highlight lua %} inv:set_lists(lists) {% endhighlight %}
Please note that the sizes of lists will not change.
Lua Tables for Lists
You can do the above for individual lists:
{% highlight lua %} local list = inv:get_list("list_one") {% endhighlight %}
It will be in this form:
{% highlight lua %} { ItemStack, ItemStack, ItemStack, ItemStack, -- inv:get_size("list_one") elements } {% endhighlight %}
You can then set the list:
{% highlight lua %} inv:set_list("list_one", list) {% endhighlight %}
Please note that the sizes of lists will not change.
InvRef, Items and Stacks
Adding to a List
To add items to a list named "main":
{% highlight lua %} local stack = ItemStack("default:stone 99") local leftover = inv:add_item("main", stack) if leftover:get_count() > 0 then print("Inventory is full! " .. leftover:get_count() .. " items weren't added") end {% endhighlight %}
Checking for Room
To check whether a list has room for items:
{% highlight lua %} if not inv:room_for_item("main", stack) then print("Not enough room!") end {% endhighlight %}
Taking Items
To remove items from a list:
{% highlight lua %} local taken = inv:remove_item("main", stack) print("Took " .. taken:get_count()) {% endhighlight %}
Checking Inventory Contents
To check whether an inventory contains a specific quantity of an item:
{% highlight lua %} if not inv:contains_item(listname, stack) then print("Item not in inventory!") end {% endhighlight %}
This works if the item count is split up over multiple stacks. For example checking for "default:stone 200" will work if there are stacks of 99 + 95 + 6.
Manipulating Stacks
You can manipulate individual stacks:
{% highlight lua %} local stack = inv:get_stack(listname, 0) inv:set_stack(listname, 0, stack) {% endhighlight %}