Classes
All groovy files are classes. However, if no specific class declaration is used, the file will be parsed as a script file.
Groovy File Extensions
A Groovy file is a file with the extension groovy, gy, gvy, or gsh.
In almost all places on the wiki, only groovy will be used.
Groovy file names must follow the Java class naming specification, meaning valid names match the regex pattern of [a-zA-Z$_][a-zA-Z0-9$_]*. To spell it out: a file name must begin with a letter, dollar sign, or underscore, and every character afterwards is must be either a letter, number, dollar sign, or underscore.
Invalid Name
If the file does not have a valid name it will not be loaded!
Global Object Confusion
As the file name will create a class with the same name, naming your file with the same name as a global object such as item, mods, eventManager, or otherwise may cause unexpected issues due to accessing the class instead of the desired global object!
Script Files
Script files must be placed in a specific loader to be run, and will be executed in that stage.
log.info('A normal script file'){
"loaders": {
"postInit": [
"postInit/Example.groovy"
]
},
}Behind the scenes, a script file will be converted like so:
import groovy.transform.Field
@Field // this annotation makes what would otherwise be a local to become a field
int baseValue = 2
def hello = 'hello, world!' // creates a local variable
log.info(hello)
int power(int n) { baseValue**n }
log.info(power(3))package postInit
import groovy.transform.Field
// imports still occur before the code
class Example extends groovy.lang.Script {
@Field
int baseValue = 2
int power(int n) { baseValue**n } // if baseValue was not annotated with @Field, an exception will be thrown!
def run() {
def hello = 'hello, world!'
log.info(hello)
log.info(power(3))
}
}Maximum method size
Java cannot load methods larger than 64kb. Particularly large GroovyScript scripts may pass this - in this situation, you will need to refactor your scripts in some fashion to avoid this issue.
Custom Classes
Basic Example
With a named DemoClass.groovy from any other groovy class.
class DemoClass {
final static def iron = item 'minecraft:iron_ingot'
final static def gold = item 'minecraft:gold_ingot'
}"loaders": {
"preInit": [
"classes/" // targets either the file or a folder that the file is nested within
]
}import classes.DemoClass
log.info(DemoClass.iron in ore('ingotIron'))
Waiting Idly