3 GitHub Repo: https://github.com/minetest/minetest_game
8 The Minetest Game subgame offers multiple new possibilities in addition to the Minetest engine's built-in API,
9 allowing you to add new plants to farming mod, buckets for new liquids, new stairs and custom panes.
10 For information on the Minetest API, visit https://github.com/minetest/minetest/blob/master/doc/lua_api.txt
13 * [XYZ] refers to a section the Minetest API
14 * [#ABC] refers to a section in this document
15 * [pos] refers to a position table `{x = -5, y = 0, z = 200}`
20 The bucket API allows registering new types of buckets for non-default liquids.
22 bucket.register_liquid(
23 "default:lava_source", -- name of the source node
24 "default:lava_flowing", -- name of the flowing node
25 "bucket:bucket_lava", -- name of the new bucket item (or nil if liquid is not takeable)
26 "bucket_lava.png", -- texture of the new bucket item (ignored if itemname == nil)
27 "Lava Bucket", -- text description of the bucket item
28 {lava_bucket = 1}, -- groups of the bucket item, OPTIONAL
29 false -- force-renew, OPTIONAL. Force the liquid source to renew if it has
30 -- a source neighbour, even if defined as 'liquid_renewable = false'.
31 -- Needed to avoid creating holes in sloping rivers.
34 The filled bucket item is returned to the player that uses an empty bucket pointing to the given liquid source.
35 When punching with an empty bucket pointing to an entity or a non-liquid node, the on_punch of the entity or node will be triggered.
41 "beds:bed", -- Bed name
42 def -- See [#Bed definition]
45 * `beds.read_spawns() ` Returns a table containing players respawn positions
46 * `beds.kick_players()` Forces all players to leave bed
47 * `beds.skip_night()` Sets world time to morning and saves respawn position of all players currently sleeping
52 description = "Simple Bed",
53 inventory_image = "beds_bed.png",
54 wield_image = "beds_bed.png",
56 bottom = {'Tile definition'}, -- the tiles of the bottom part of the bed.
57 top = {Tile definition} -- the tiles of the bottom part of the bed.
60 bottom = 'regular nodebox', -- bottom part of bed (see [Node boxes])
61 top = 'regular nodebox', -- top part of bed (see [Node boxes])
63 selectionbox = 'regular nodebox', -- for both nodeboxes (see [Node boxes])
64 recipe = { -- Craft recipe
65 {"group:wool", "group:wool", "group:wool"},
66 {"group:wood", "group:wood", "group:wood"}
73 Use `creative.register_tab(name, title, items)` to add a tab with filtered items.
76 creative.register_tab("tools", "Tools", minetest.registered_tools)
78 is used to show all tools. Name is used in the sfinv page name, title is the
81 `is_enabled_for` is used to check whether a player is in creative mode:
83 creative.is_enabled_for(name)
85 Override this to allow per-player game modes.
87 The contents of `creative.formspec_add` is appended to every creative inventory
88 page. Mods can use it to add additional formspec elements onto the default
89 creative inventory formspec to be drawn after each update.
94 The doors mod allows modders to register custom doors and trapdoors.
96 `doors.register_door(name, def)`
99 * `name` Name for door
100 * `def` See [#Door definition]
102 `doors.register_trapdoor(name, def)`
104 * Registers new trapdoor
105 * `name` Name for trapdoor
106 * `def` See [#Trapdoor definition]
108 `doors.register_fencegate(name, def)`
110 * Registers new fence gate
111 * `name` Name for fence gate
112 * `def` See [#Fence gate definition]
116 * `pos` A position as a table, e.g `{x = 1, y = 1, z = 1}`
117 * Returns an ObjectRef to a door, or nil if the position does not contain a door
121 :open(player) -- Open the door object, returns if door was opened
122 :close(player) -- Close the door object, returns if door was closed
123 :toggle(player) -- Toggle the door state, returns if state was toggled
124 :state() -- returns the door state, true = open, false = closed
126 the "player" parameter can be omitted in all methods. If passed then
127 the usual permission checks will be performed to make sure the player
128 has the permissions needed to open this door. If omitted then no
129 permission checks are performed.
133 description = "Door description",
134 inventory_image = "mod_door_inv.png",
135 groups = {choppy = 2},
136 tiles = {"mod_door.png"}, -- UV map.
137 recipe = craftrecipe,
138 sounds = default.node_sound_wood_defaults(), -- optional
139 sound_open = sound play for open door, -- optional
140 sound_close = sound play for close door, -- optional
141 protected = false, -- If true, only placer can open the door (locked for others)
143 ### Trapdoor definition
145 description = "Trapdoor description",
146 inventory_image = "mod_trapdoor_inv.png",
147 groups = {choppy = 2},
148 tile_front = "doors_trapdoor.png", -- the texture for the front and back of the trapdoor
149 tile_side = "doors_trapdoor_side.png", -- the tiles of the four side parts of the trapdoor
150 sounds = default.node_sound_wood_defaults(), -- optional
151 sound_open = sound play for open door, -- optional
152 sound_close = sound play for close door, -- optional
153 protected = false, -- If true, only placer can open the door (locked for others)
155 ### Fence gate definition
157 description = "Wooden Fence Gate",
158 texture = "default_wood.png",
159 material = "default:wood",
160 groups = {choppy = 2, oddly_breakable_by_hand = 2, flammable = 2},
161 sounds = default.node_sound_wood_defaults(), -- optional
166 Allows creation of new fences with "fencelike" drawtype.
168 `default.register_fence(name, item definition)`
170 Registers a new fence. Custom fields texture and material are required, as
171 are name and description. The rest is optional. You can pass most normal
172 nodedef fields here except drawtype. The fence group will always be added
177 name = "default:fence_wood",
178 description = "Wooden Fence",
179 texture = "default_wood.png",
180 material = "default:wood",
181 groups = {choppy = 2, oddly_breakable_by_hand = 2, flammable = 2},
182 sounds = default.node_sound_wood_defaults(),
187 The walls API allows easy addition of stone auto-connecting wall nodes.
189 walls.register(name, desc, texture, mat, sounds)
190 ^ name = "walls:stone_wall". Node name.
191 ^ desc = "A Stone wall"
192 ^ texture = "default_stone.png"
193 ^ mat = "default:stone". Used to auto-generate crafting recipe.
194 ^ sounds = sounds: see [#Default sounds]
199 The farming API allows you to easily register plants and hoes.
201 `farming.register_hoe(name, hoe definition)`
202 * Register a new hoe, see [#hoe definition]
204 `farming.register_plant(name, Plant definition)`
205 * Register a new growing plant, see [#Plant definition]
207 `farming.registered_plants[name] = definition`
208 * Table of registered plants, indexed by plant name
214 description = "", -- Description for tooltip
215 inventory_image = "unknown_item.png", -- Image to be used as wield- and inventory image
216 max_uses = 30, -- Uses until destroyed
217 material = "", -- Material for recipes
218 recipe = { -- Craft recipe, if material isn't used
219 {"air", "air", "air"},
228 description = "", -- Description of seed item
229 inventory_image = "unknown_item.png", -- Image to be used as seed's wield- and inventory image
230 steps = 8, -- How many steps the plant has to grow, until it can be harvested
231 -- ^ Always provide a plant texture for each step, format: modname_plantname_i.png (i = stepnumber)
232 minlight = 13, -- Minimum light to grow
233 maxlight = default.LIGHT_MAX -- Maximum light to grow
239 New node def property:
243 * Called when fire attempts to remove a burning node.
244 * `pos` Position of the burning node.
246 `on_ignite(pos, igniter)`
248 * Called when Flint and steel (or a mod defined ignitor) is used on a node.
249 Defining it may prevent the default action (spawning flames) from triggering.
250 * `pos` Position of the ignited node.
251 * `igniter` Player that used the tool, when available.
254 Give Initial Stuff API
255 ----------------------
257 `give_initial_stuff.give(player)`
259 ^ Give initial stuff to "player"
261 `give_initial_stuff.add(stack)`
263 ^ Add item to the initial stuff
264 ^ Stack can be an ItemStack or a item name eg: "default:dirt 99"
265 ^ Can be called after the game has loaded
267 `give_initial_stuff.clear()`
269 ^ Removes all items from the initial stuff
270 ^ Can be called after the game has loaded
272 `give_initial_stuff.get_list()`
274 ^ returns list of item stacks
276 `give_initial_stuff.set_list(list)`
278 ^ List of initial items with numeric indices.
280 `give_initial_stuff.add_from_csv(str)`
282 ^ str is a comma separated list of initial stuff
283 ^ Adds items to the list of items to be given
288 `nyancat.place(pos, facedir, length)`
290 ^ Place a cat at `pos` facing `facedir` with tail length `length`
291 Only accepts facedir 0-3, if facedir > 3 then it will be interpreted as facedir = 0
293 `nyancat.generate(minp, maxp, seed)`
295 ^ Called by `minetest.register_on_generated`. To disable nyancat generation,
296 you can redefine nyancat.generate() to be an empty function
301 `tnt.register_tnt(definition)`
303 ^ Register a new type of tnt.
305 * `name` The name of the node. If no prefix is given `tnt` is used.
306 * `description` A description for your TNT.
307 * `radius` The radius within which the TNT can destroy nodes. The default is 3.
308 * `damage_radius` The radius within which the TNT can damage players and mobs. By default it is twice the `radius`.
309 * `disable_drops` Disable drops. By default it is set to false.
310 * `ignore_protection` Don't check `minetest.is_protected` before removing a node.
311 * `ignore_on_blast` Don't call `on_blast` even if a node has one.
312 * `tiles` Textures for node
313 * `side` Side tiles. By default the name of the tnt with a suffix of `_side.png`.
314 * `top` Top tile. By default the name of the tnt with a suffix of `_top.png`.
315 * `bottom` Bottom tile. By default the name of the tnt with a suffix of `_bottom.png`.
316 * `burning` Top tile when lit. By default the name of the tnt with a suffix of `_top_burning_animated.png".
318 `tnt.boom(position, definition)`
320 ^ Create an explosion.
322 * `position` The center of explosion.
323 * `definition` The TNT definion as passed to `tnt.register`
325 `tnt.burn(position, [nodename])`
327 ^ Ignite TNT at position, nodename isn't required unless already known.
330 To make dropping items from node inventories easier, you can use the
331 following helper function from 'default':
333 default.get_inventory_drops(pos, inventory, drops)
335 ^ Return drops from node inventory "inventory" in drops.
337 * `pos` - the node position
338 * `inventory` - the name of the inventory (string)
339 * `drops` - an initialized list
341 The function returns no values. The drops are returned in the `drops`
342 parameter, and drops is not reinitialized so you can call it several
343 times in a row to add more inventory items to it.
346 `on_blast` callbacks:
348 Both nodedefs and entitydefs can provide an `on_blast()` callback
350 `nodedef.on_blast(pos, intensity)`
351 ^ Allow drop and node removal overriding
352 * `pos` - node position
353 * `intensity` - TNT explosion measure. larger or equal to 1.0
354 ^ Should return a list of drops (e.g. {"default:stone"})
355 ^ Should perform node removal itself. If callback exists in the nodedef
356 ^ then the TNT code will not destroy this node.
358 `entitydef.on_blast(luaobj, damage)`
359 ^ Allow TNT effects on entities to be overridden
360 * `luaobj` - LuaEntityRef of the entity
361 * `damage` - suggested HP damage value
362 ^ Should return a list of (bool do_damage, bool do_knockback, table drops)
363 * `do_damage` - if true then TNT mod wil damage the entity
364 * `do_knockback` - if true then TNT mod will knock the entity away
365 * `drops` - a list of drops, e.g. {"wool:red"}
371 The screwdriver API allows you to control a node's behaviour when a screwdriver is used on it.
372 To use it, add the `on_screwdriver` function to the node definition.
374 `on_rotate(pos, node, user, mode, new_param2)`
376 * `pos` Position of the node that the screwdriver is being used on
378 * `user` The player who used the screwdriver
379 * `mode` screwdriver.ROTATE_FACE or screwdriver.ROTATE_AXIS
380 * `new_param2` the new value of param2 that would have been set if on_rotate wasn't there
381 * return value: false to disallow rotation, nil to keep default behaviour, true to allow
382 it but to indicate that changed have already been made (so the screwdriver will wear out)
383 * use `on_rotate = false` to always disallow rotation
384 * use `on_rotate = screwdriver.rotate_simple` to allow only face rotation
390 The sethome API adds three global functions to allow mods to read a players home position,
391 set a players home position and teleport a player to home position.
395 * `name` Player who's home position you wish to get
396 * return value: false if no player home coords exist, position table if true
398 `sethome.set(name, pos)`
400 * `name` Player who's home position you wish to set
401 * `pos` Position table containing coords of home position
402 * return value: false if unable to set and save new home position, otherwise true
406 * `name` Player you wish to teleport to their home position
407 * return value: false if player cannot be sent home, otherwise true
417 * sfinv.set_page(player, pagename) - changes the page
418 * sfinv.get_homepage_name(player) - get the page name of the first page to show to a player
419 * sfinv.register_page(name, def) - register a page, see section below
420 * sfinv.override_page(name, def) - overrides fields of an page registered with register_page.
421 * Note: Page must already be defined, (opt)depend on the mod defining it.
422 * sfinv.set_player_inventory_formspec(player) - (re)builds page formspec
423 and calls set_inventory_formspec().
424 * sfinv.get_formspec(player, context) - builds current page's formspec
428 * sfinv.get_or_create_context(player) - gets the player's context
429 * sfinv.set_context(player, context)
433 * sfinv.make_formspec(player, context, content, show_inv, size) - adds a theme to a formspec
434 * show_inv, defaults to false. Whether to show the player's main inventory
435 * size, defaults to `size[8,8.6]` if not specified
436 * sfinv.get_nav_fs(player, context, nav, current_idx) - creates tabheader or ""
440 * pages - table of pages[pagename] = def
441 * pages_unordered - array table of pages in order of addition (used to build navigation tabs).
442 * contexts - contexts[playername] = player_context
443 * enabled - set to false to disable. Good for inventory rehaul mods like unified inventory
447 A table with these keys:
449 * page - current page name
450 * nav - a list of page names
451 * nav_titles - a list of page titles
452 * nav_idx - current nav index (in nav and nav_titles)
453 * any thing you want to store
454 * sfinv will clear the stored data on log out / log in
456 ### sfinv.register_page
458 sfinv.register_page(name, def)
460 def is a table containing:
462 * `title` - human readable page name (required)
463 * `get(self, player, context)` - returns a formspec string. See formspec variables. (required)
464 * `is_in_nav(self, player, context)` - return true to show in the navigation (the tab header, by default)
465 * `on_player_receive_fields(self, player, context, fields)` - on formspec submit.
466 * `on_enter(self, player, context)` - called when the player changes pages, usually using the tabs.
467 * `on_leave(self, player, context)` - when leaving this page to go to another, called before other's on_enter
471 Use sfinv.make_formspec to apply a layout:
473 return sfinv.make_formspec(player, context, [[
474 list[current_player;craft;1.75,0.5;3,3;]
475 list[current_player;craftpreview;5.75,1.5;1,1;]
476 image[4.75,1.5;1,1;gui_furnace_arrow_bg.png^[transformR270]
477 listring[current_player;main]
478 listring[current_player;craft]
479 image[0,4.25;1,1;gui_hb_bg.png]
480 image[1,4.25;1,1;gui_hb_bg.png]
481 image[2,4.25;1,1;gui_hb_bg.png]
482 image[3,4.25;1,1;gui_hb_bg.png]
483 image[4,4.25;1,1;gui_hb_bg.png]
484 image[5,4.25;1,1;gui_hb_bg.png]
485 image[6,4.25;1,1;gui_hb_bg.png]
486 image[7,4.25;1,1;gui_hb_bg.png]
489 See above (methods section) for more options.
491 ### Customising themes
493 Simply override this function to change the navigation:
495 function sfinv.get_nav_fs(player, context, nav, current_idx)
499 And override this function to change the layout:
501 function sfinv.make_formspec(player, context, content, show_inv, size)
503 size or "size[8,8.6]",
505 sfinv.get_nav_fs(player, context, context.nav_titles, context.nav_idx),
511 return table.concat(tmp, "")
517 The stairs API lets you register stairs and slabs and ensures that they are registered the same way as those
518 delivered with Minetest Game, to keep them compatible with other mods.
520 `stairs.register_stair(subname, recipeitem, groups, images, description, sounds)`
523 * `subname`: Basically the material name (e.g. cobble) used for the stair name. Nodename pattern: "stairs:stair_subname"
524 * `recipeitem`: Item used in the craft recipe, e.g. "default:cobble", may be `nil`
525 * `groups`: see [Known damage and digging time defining groups]
526 * `images`: see [Tile definition]
527 * `description`: used for the description field in the stair's definition
528 * `sounds`: see [#Default sounds]
530 `stairs.register_slab(subname, recipeitem, groups, images, description, sounds)`
533 * `subname`: Basically the material name (e.g. cobble) used for the stair name. Nodename pattern: "stairs:stair_subname"
534 * `recipeitem`: Item used in the craft recipe, e.g. "default:cobble"
535 * `groups`: see [Known damage and digging time defining groups]
536 * `images`: see [Tile definition]
537 * `description`: used for the description field in the stair's definition
538 * `sounds`: see [#Default sounds]
540 `stairs.register_stair_and_slab(subname, recipeitem, groups, images, desc_stair, desc_slab, sounds)`
542 * A wrapper for stairs.register_stair and stairs.register_slab
543 * Uses almost the same arguments as stairs.register_stair
544 * `desc_stair`: Description for stair node
545 * `desc_slab`: Description for slab node
550 Creates panes that automatically connect to each other
552 `xpanes.register_pane(subname, def)`
554 * `subname`: used for nodename. Result: "xpanes:subname" and "xpanes:subname_{2..15}"
555 * `def`: See [#Pane definition]
560 textures = {"texture for sides", (unused), "texture for top and bottom"}, -- More tiles aren't supported
561 groups = {group = rating}, -- Uses the known node groups, see [Known damage and digging time defining groups]
562 sounds = SoundSpec, -- See [#Default sounds]
563 recipe = {{"","","","","","","","",""}}, -- Recipe field only
569 The following nodes use the group `connect_to_raillike` and will only connect to
570 raillike nodes within this group and the same group value.
571 Use `minetest.raillike_group(<Name>)` to get the group value.
573 | Node type | Raillike group name
574 |-----------------------|---------------------
575 | default:rail | "rail"
576 | tnt:gunpowder | "gunpowder"
577 | tnt:gunpowder_burning | "gunpowder"
580 If you want to add a new rail type and want it to connect with default:rail,
581 add `connect_to_raillike=minetest.raillike_group("rail")` into the `groups` table
588 Sounds inside the default table can be used within the sounds field of node definitions.
590 * `default.node_sound_defaults()`
591 * `default.node_sound_stone_defaults()`
592 * `default.node_sound_dirt_defaults()`
593 * `default.node_sound_sand_defaults()`
594 * `default.node_sound_wood_defaults()`
595 * `default.node_sound_leaves_defaults()`
596 * `default.node_sound_glass_defaults()`
597 * `default.node_sound_metal_defaults()`
602 `default.LIGHT_MAX` The maximum light level (see [Node definition] light_source)
607 The player API can register player models and update the player's appearence
609 `default.player_register_model(name, def)`
611 * Register a new model to be used by players.
612 * name: model filename such as "character.x", "foo.b3d", etc.
613 * def: See [#Model definition]
615 `default.registered_player_models[name]`
617 * Get a model's definition
618 * see [#Model definition]
620 `default.player_set_model(player, model_name)`
622 * Change a player's model
623 * `player`: PlayerRef
624 * `model_name`: model registered with player_register_model()
626 `default.player_set_animation(player, anim_name [, speed])`
628 * Applies an animation to a player
629 * anim_name: name of the animation.
630 * speed: frames per second. If nil, default from the model is used
632 `default.player_set_textures(player, textures)`
634 * Sets player textures
635 * `player`: PlayerRef
636 * `textures`: array of textures, If `textures` is nil, the default textures from the model def are used
638 default.player_get_animation(player)
640 * Returns a table containing fields `model`, `textures` and `animation`.
641 * Any of the fields of the returned table may be nil.
647 animation_speed = 30, -- Default animation speed, in FPS.
648 textures = {"character.png", }, -- Default array of textures.
649 visual_size = {x = 1, y = 1}, -- Used to scale the model.
651 -- <anim_name> = {x = <start_frame>, y = <end_frame>},
652 foo = {x = 0, y = 19},
653 bar = {x = 20, y = 39},
661 To enable leaf decay for leaves when a tree is cut down by a player,
662 register the tree with the default.register_leafdecay(leafdecaydef)
665 If `param2` of any registered node is ~= 0, the node will always be
666 preserved. Thus, if the player places a node of that kind, you will
667 want to set `param2 = 1` or so.
669 The function `default.after_place_leaves` can be set as
670 `after_place_node of a node` to set param2 to 1 if the player places
671 the node (should not be used for nodes that use param2 otherwise
674 If the node is in the `leafdecay_drop` group then it will always be
677 `default.register_leafdecay(leafdecaydef)`
679 `leafdecaydef` is a table, with following members:
681 trunks = {"default:tree"}, -- nodes considered trunks
682 leaves = {"default:leaves", "default:apple"},
683 -- nodes considered for removal
684 radius = 3, -- radius to consider for searching
687 Note: all the listed nodes in `trunks` have their `on_after_destruct`
688 callback overridden. All the nodes listed in `leaves` have their
689 `on_timer` callback overridden.
695 To make recipes that will work with any dye ever made by anybody, define
696 them based on groups. You can select any group of groups, based on your need for
711 * `basecolor_magenta`
713 Extended color groups ( * means also base color )
716 * `excolor_lightgrey`
730 * `excolor_magenta` *
731 * `excolor_red_violet`
733 The whole unifieddyes palette as groups:
735 * `unicolor_<excolor>`
737 For the following, no white/grey/black is allowed:
739 * `unicolor_medium_<excolor>`
740 * `unicolor_dark_<excolor>`
741 * `unicolor_light_<excolor>`
742 * `unicolor_<excolor>_s50`
743 * `unicolor_medium_<excolor>_s50`
744 * `unicolor_dark_<excolor>_s50`
746 Example of one shapeless recipe using a color group:
748 minetest.register_craft({
750 output = '<mod>:item_yellow',
751 recipe = {'<mod>:item_no_color', 'group:basecolor_yellow'},
756 * `dye.basecolors` are an array containing the names of available base colors
758 * `dye.excolors` are an array containing the names of the available extended colors
763 * `default.grow_tree(pos, is_apple_tree)`
764 * Grows a mgv6 tree or apple tree at pos
766 * `default.grow_jungle_tree(pos)`
767 * Grows a mgv6 jungletree at pos
769 * `default.grow_pine_tree(pos)`
770 * Grows a mgv6 pinetree at pos
772 * `default.grow_new_apple_tree(pos)`
773 * Grows a new design apple tree at pos
775 * `default.grow_new_jungle_tree(pos)`
776 * Grows a new design jungle tree at pos
778 * `default.grow_new_pine_tree(pos)`
779 * Grows a new design pine tree at pos
781 * `default.grow_new_acacia_tree(pos)`
782 * Grows a new design acacia tree at pos
784 * `default.grow_new_aspen_tree(pos)`
785 * Grows a new design aspen tree at pos
787 * `default.grow_new_snowy_pine_tree(pos)`
788 * Grows a new design snowy pine tree at pos
794 "mycarts:myrail", -- Rail name
795 nodedef, -- standard nodedef
796 railparams -- rail parameter struct (optional)
800 on_step(obj, dtime), -- Event handler called when
802 acceleration, -- integer acceleration factor (negative
806 The event handler is called after all default calculations
807 are made, so the custom on_step handler can override things
808 like speed, acceleration, player attachment. The handler will
809 likely be called many times per second, so the function needs
810 to make sure that the event is handled properly.
815 The key API allows mods to add key functionality to nodes that have
816 ownership or specific permissions. Using the API will make it so
817 that a node owner can use skeleton keys on their nodes to create keys
818 for that node in that location, and give that key to other players,
819 allowing them some sort of access that they otherwise would not have
820 due to node protection.
822 To make your new nodes work with the key API, you need to register
823 two callback functions in each nodedef:
826 `on_key_use(pos, player)`
827 * Is called when a player right-clicks (uses) a normal key on your
829 * `pos` - position of the node
830 * `player` - PlayerRef
831 * return value: none, ignored
833 The `on_key_use` callback should validate that the player is wielding
834 a key item with the right key meta secret. If needed the code should
835 deny access to the node functionality.
837 If formspecs are used, the formspec callbacks should duplicate these
838 checks in the metadata callback functions.
841 `on_skeleton_key_use(pos, player, newsecret)`
843 * Is called when a player right-clicks (uses) a skeleton key on your
845 * `pos` - position of the node
846 * `player` - PlayerRef
847 * `newsecret` - a secret value(string)
849 * `secret` - `nil` or the secret value that unlocks the door
850 * `name` - a string description of the node ("a locked chest")
851 * `owner` - name of the node owner
853 The `on_skeleton_key_use` function should validate that the player has
854 the right permissions to make a new key for the item. The newsecret
855 value is useful if the node has no secret value. The function should
856 store this secret value somewhere so that in the future it may compare
857 key secrets and match them to allow access. If a node already has a
858 secret value, the function should return that secret value instead
859 of the newsecret value. The secret value stored for the node should
860 not be overwritten, as this would invalidate existing keys.
862 Aside from the secret value, the function should retun a descriptive
863 name for the node and the owner name. The return values are all
864 encoded in the key that will be given to the player in replacement
865 for the wielded skeleton key.
867 if `nil` is returned, it is assumed that the wielder did not have
868 permissions to create a key for this node, and no key is created.