This page explains aliases, an advanced YAML technique which can save you from having to repeat the same Parameters or groups of parameters in your drops file. Aliases are typically defined in the
aliases: section of a drops file, though they can in fact be defined anywhere.
YAML allows you to use an advanced tool called "aliases". These tricks work in any config file that's written in YAML.
Aliases allow you to define a string/list/number or even a whole block of data, give it a name and recall it later with just that name. You can even modify sub-sections of the data when recalling the alias.
Some examples follow:
aliases: # example of an alias that defines just a single piece of data - &environ [DAMAGE_ENTITY_EXPLOSION, DAMAGE_FIRE, DAMAGE_CONTACT, DAMAGE_DROWNING, DAMAGE_FALL, DAMAGE_SUFFOCATION] # example of an alias that defines a block of data, using the previously defined alias - &environDropNothing tool: *environ drop: NOTHING exclusive: 1 # this means that if this drop occurs - none of the others will, unless they have the same number otherblocks: CREATURE_ZOMBIE: - &environDropNothing # stop mob farming - no environmental drops # continue with any other custom drops....
Modifying alias contents
The following example is designed to allow you to easily copy a similar config between different blocks whilst modifying a section of the alias. Note the use of <:: (a "merge key") as this is what allows you to modify the alias.
aliases: - &damageall tool: ALL drop: AIR damageattacker: 1 - &dropnothing tool: ALL drop: NOTHING chance: 100 - &defaultdroplow # this alias has a low chance of dropping default item tool: ALL drop: DEFAULT chance: 5 - &specitem # this alias is being used specifically for overwriting the "tool" condition later tool: ALL drop: DEFAULT chance: 100 exclusive: 1 otherblocks: #stones STONE: - *dropnothing - *damageall - *defaultdroplow - <<: *specitem tool: ANY_PICKAXE DIRT: - *dropnothing - *damageall - *defaultdroplow - <<: *specitem tool: ANY_SPADE
Defining aliases from modified aliases
Again a more advanced example. Pay attention to how `&specitem-pick` is defined from a modification of the `&specitem` alias.
# original example by enelar ALIASES: #1) With fingers - damage attacker, nothing changed with block. (&damageall) #2) On wrong tool - nothing changed with block. (&wrongtool) #3) On pickaxe, each race individual chance to drop, always drops cobblestone. #4) Kill player else. (Broken with dirt, sand, fish, seeds, etc) (&atata) - &wrongtool tool: ANY drop: DENY exclusive: wrong - &atata damageattacker: 20 tool: ANY drop: NOTHING toolexcept: [ANY_SPADE, ANY_AXE, ANY_HOE, ANY_PICKAXE] replacementblock: DEFAULT message: "WTF! Wrong item... Non RP playing..." exclusive: atata - &damageall tool: ALL drop: AIR replacementblock: DEFAULT message: "Oh, my fingers!" damageattacker: 1 - &defaultdroplow tool: ALL drop: DEFAULT chance: 5 - &specitem tool: ALL drop: DEFAULT chance: 100 exclusive: 1 - &dropstone tool: ANY_PICKAXE drop: COBBLESTONE exclusive: 1 COAL_ORE: - <<: *wrongtool toolexcept: ANY_PICKAXE - <<: *damageall damageattacker: 8 - <<: *atata - <<: *dropstone - &specitem-pick <<: *specitem tool: ANY_PICKAXE chance: 40 permissions: race_a.COAL_ORE - <<: *specitem-pick chance: 60 permissions: race_h.COAL_ORE - <<: *specitem-pick chance: 60 permissions: race_t.COAL_ORE - <<: *specitem-pick chance: 5 permissions: race_r.COAL_ORE
If you missed it here is the specific part defining `&specitem-pick`:
- &specitem-pick # note: this alias name must be on it's own line <<: *specitem # remember, <<: allows you to modify the alias tool: ANY_PICKAXE # change tool from &specitem's ALL value to ANY_PICKAXE
Use with DropGroups
Aliases can also be used with DropGroups to create more complex aliases.
aliases: - &map_and_compass dropgroup: mapcompass chance: 0.01% drops: - drop: MAP - drop: COMPASS otherblocks: SAND: - *map_and_compass
This likely has more practical applications (as you probably wouldn't want to define the mapcompass drop more than once). I might improve this example later with a more practical example if I think of one.
A nice reference with some advanced examples is shown in the SnakeYAML documentation (http://code.google.com/p/snakeyaml/wiki/Documentation#Aliases) (aliases) and (http://code.google.com/p/snakeyaml/wiki/Documentation#Merge) (merges).
Alias nodes are described in the YAML specification: http://www.yaml.org/spec/1.2/spec.html#id2786196. A basic example is also shown in Example 2.24 on that page.