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Your First Script

Writing Your First Script

If you have launched the game at least once before you will find kubejs/server_scripts/example_server_script.js It looks like this:

// priority: 0

settings.logAddedRecipes = true
settings.logRemovedRecipes = true
settings.logSkippedRecipes = false
settings.logErroringRecipes = true

console.info('Hello, World! (You will see this line every time server resources reload)')

onEvent('recipes', event => {
	// Change recipes here
})

onEvent('item.tags', event => {
	// Get the #forge:cobblestone tag collection and add Diamond Ore to it
	// event.get('forge:cobblestone').add('minecraft:diamond_ore')

	// Get the #forge:cobblestone tag collection and remove Mossy Cobblestone from it
	// event.get('forge:cobblestone').remove('minecraft:mossy_cobblestone')
})

Lets break it down:

  • // priority: 0
    • Makes it so that if you have multiple server scripts, this script gets loaded first
    • If you have only one server_script, this has no effect
  • settings.logAddedRecipes = true
    settings.logRemovedRecipes = true
    settings.logSkippedRecipes = false
    settings.logErroringRecipes = true
    • sets settings for what messages are logged
    • You can remove all four of these lines if you want and it will only change what is put into the logs
  • console.info('Hello, World! (You will see this line every time server resources reload)')
    • Prints the message in the log
    • This line is useless other then example and should be removed eventually
  • onEvent('recipes', event => {
    • This makes an event listener for the recipes event, and will run the code inside when and only when the recipes event is triggered
    • This is triggered when server resources reload
      • Which happens when the world load or the /reload command is used
  • // Change recipes here
    • comment, an code in a line following // will be considered a comment and will not be run
    • Used for taking notes as you write the code
  • })
    • Indicates the end of the 'recipes' event listener

  • onEvent('item.tags', event => {
        // Get the #forge:cobblestone tag collection and add Diamond Ore to it
        // event.get('forge:cobblestone').add('minecraft:diamond_ore')

        // Get the #forge:cobblestone tag collection and remove Mossy Cobblestone from it
        // event.get('forge:cobblestone').remove('minecraft:mossy_cobblestone')
    })

    • Same thing as the other one but for the item.tags event
    • You can find the list of all event here

Finally Writing Code For Real

Lets start off by adding a recipe to craft flint from three gravel.

To do so, insert this code right after the recipes event.

event.shapeless("flint", ["gravel", "gravel", "gravel"])

It should look like this:

// priority: 0

settings.logAddedRecipes = true
settings.logRemovedRecipes = true
settings.logSkippedRecipes = false
settings.logErroringRecipes = true

console.info('Hello, World! (You will see this line every time server resources reload)')

onEvent('recipes', event => {
	// Change recipes here
	event.shapeless("flint", ["gravel", "gravel", "gravel"])
})

onEvent('item.tags', event => {
	// Get the #forge:cobblestone tag collection and add Diamond Ore to it
	// event.get('forge:cobblestone').add('minecraft:diamond_ore')

	// Get the #forge:cobblestone tag collection and remove Mossy Cobblestone from it
	// event.get('forge:cobblestone').remove('minecraft:mossy_cobblestone')
})

Now lets test it!

Run the command /reload in game, then try crafting three gravel together in any order.

But how does it work?

  • event
    • This is a variable that created with the arrow expression in onEvent('recipes', event => {...
      • You can have the name be what every you choose, as long as it matches everywhere
  • .
    • The dot operator is used for calling a method of an object
    • In this case event is the object and shapeless is the method
  • shapeless(
    • This is the method that is called by the dot operator on the event
    • It is taking two arguments, that being an item result and a array input
  • "
    • Indicates the start of a string
  • flint
    • The contents of the string
    • You can use create:flour , if it is from a different mod (flint is the same as minecraft:flint, and both are valid)
  • "
    • Signifies the end of the string.
    • A string is simply a sequence of characters, or letters
    • You can read more about strings in JS here.
  • ,
    • separates different arguments in the method.
  • [
    • Signifies the start of the array.
    • An array holds multiple values or any type, including other arrays.
    • You can read more about arrays in JS here.
  • "gravel", "gravel", "gravel"
    • The contents of the array
    • Arrays can hold an indefinite number of elements
  • ]
    • Closing the array
  • )
    • Closing the method

There you go! You can make custom shapeless recipes!

If you want to make other types of recipes, learn about it here, and if you have an addon that adds more recipe types, loot at its mod page, or here.

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