Quick Start

Installation

To get started with INJ, follow these steps:

After installation, you can use the inj command from any directory in your terminal.

File Structure

INJ follows the same file structure as Minecraft datapacks. Your source directory (typically named src) mirrors the structure of a datapack's data folder:

src/
├─<your_namespace>
│  ├─advancements
│  ├─functions
│  │  ├─test.inj
│  │  └─hello.inj
│  ├─loot_tables
│  ├─recipes
│  └─tags
└─minecraft
    ├─dimension
    ├─dimension_type
    ├─loot_tables
    └─tags

Place your src directory alongside the data folder in your datapack. Edit files directly in src, then compile using:

inj <src_directory>          # Basic compilation
inj <src_directory> -o <output_directory>    # Specify output directory
inj <src_directory> --watch  # Watch mode: auto-compile on changes

INJ Syntax

INJ enhances Minecraft functions by allowing you to write JavaScript code alongside Minecraft commands. While knowing JavaScript can help you unlock INJ's full potential, you only need to understand a few basic concepts to get started:

• if statements
• while loops and for loops
• let declarations
• Template literals

Running Minecraft Commands

You can directly write Minecraft commands in any line of your INJ code:

if (2 != 1) {
    // This line is a Minecraft command that does not require modification
    say "2 is not equal to 1"
}

You can also use $() to execute Minecraft commands. This function is particularly useful when you need to incorporate JavaScript variables into your commands:

// Basic usage
$(`say Hello, world!`);
 
// Using JavaScript variables
const playerName = "Steve";
$(`tell ${playerName} Welcome!`);
 
// Creating patterns with loops
for (let i = 0; i < 10; i++) {
    $(`setblock ~${i} ~ ~${i} minecraft:stone`);
}

Advanced Example: Creating Shapes

Here's how to create a circle of arrows using JavaScript math functions:

// Create a circle of arrows with radius 10
const radius = 10;
for (let i = 0; i < 100; i++) {
    const angle = (i / 100) * 2 * Math.PI;
    const x = (Math.cos(angle) * radius).toFixed(2);
    const z = (Math.sin(angle) * radius).toFixed(2);
    $(`summon minecraft:arrow ~${x} ~ ~${z}`);
}

Conditional Logic

You can use if statements to add conditional logic to your code. The conditions can be written in pure JavaScript syntax. For Minecraft-specific conditions, write them as JavaScript strings, such as "block ~ ~ ~ minecraft:air" or "score @r inj_score = 3".

There are three ways to write conditions:

1. if (<minecraft_condition>) {}
2. if (<js_condition>) {}
3. if (<minecraft_condition>.and(<js_condition>)) {}

Note: You can use either and() or or() to combine conditions.

The rest of the if statement syntax follows standard JavaScript conventions.

// Minecraft condition
if ("block ~ ~ ~ minecraft:stone") {
    $(`tellraw @s ["Found a stone block!"]`);
}
 
// JavaScript condition
if (a % 2 == 0) {
    say "a is even"
}
 
// Combined conditions using .and() or .or()
if ("block ~ ~ ~ minecraft:stone".and(a % 2 == 0)) {
    say "Here is a stone and 'a' is even!"
}

Loops

While INJ supports both for and while loops, while loops currently only work with JavaScript conditions:

let count = 0;
while (count < 5) {
    $(`say Count: ${count}`);
    count++;
}

We will be supporting mixed JavaScript and Minecraft conditions for while loops in the future.

Here's another example showing how to create a line of stone using a for loop:

for (let i = 0; i < 10; i++) {
    $(`setblock ~${i} ~ ~${i} minecraft:stone`);
}

And an arrow circle:

// Create a circle of arrows with radius 10
const radius = 10;
for (let i = 0; i < 100; i++) {
    const angle = (i / 100) * 2 * Math.PI;
    const x = (Math.cos(angle) * radius).toFixed(2);
    const z = (Math.sin(angle) * radius).toFixed(2);
    $(`summon minecraft:arrow ~${x} ~ ~${z}`);
}

For more advanced JavaScript concepts and features, refer to MDN Web Docs.