mcnbt

Yet another Minecraft NBT format file / buffer parser for Node.js.

Usage no npm install needed!

<script type="module">
  import mcnbt from 'https://cdn.skypack.dev/mcnbt';
</script>

README

MCNBT

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Yet another Minecraft NBT format file / buffer parser for Node.js.

Installation

$ npm install --save mcnbt

Usage

First require this package into your code:

const NBT = require('mcnbt');

Load & Parse NBT

There're several function for you to parse an NBT structure after you instantiating an object:

  • loadFromBuffer(buff, callback)
  • loadFromZlibCompressedBuffer(buff, callback)
  • loadFromFile(filename, callback)
  • loadFromZlibCompressedFile(filename, callback)

All those functions's callback should be written like:

function(err) {
  //... Your code here
}

For an example:

var nbt = new NBT();
nbt.loadFromZlibCompressedFile('level.dat', function(err) {
  if(err) return console.error(err);
  console.log(nbt);
});

Write Back To NBT

Two methods for you to write NBT:

  • writeToCompressedBuffer(callback, [method])
  • writeToBuffer(): returns the buffer (sync)
  • writeToCompressedFile(filename, callback, [method])
  • writeToFile(filename, callback)

method is an optional parameter that indicates the zlib algorithm. The default value is 'gzip'.

Get Tag(s)

After parsing your NBT, you can get the root tag(s).

  • keys(): get the root tag-key(s) into an array
  • count(): root tag(s) count
  • select(tagname): this function will returns you a instance of tag which named tagname

The tag(s) are instance(s) of BaseTag. There're 10 subclasses of BaseTag.

Tag Class

All the tag classes's parent class is BaseTag.

BaseTag and all of the tags have functions below:

  • getType(): get this tag's type name. eg. 'TAG_Compound'
  • getId(): alias of getType
  • getTypeId(): get this tag's type id. eg. 'TAG_Compound''s id is 10
  • getName(): get this tag's name
  • getValue(): get this tag's content
  • setValue(value): set this tag's value
  • count(): get this tag's children count / length (if any)
  • selectAt(idx): get this tag's children / char at idx (if any)
  • select(tagname): get this tag's children by tagname (if any)
  • getAt(idx): alias of selectAt
  • get(tagname): alias of select
  • toJSON(): convert this tag and all of its children into a JSON object

TAGByte

The value's type is byte (number in js).

No extra method.

TAGShort

The value's type is short (number in js).

No extra method.

TAGInt

The value's type is integer (number in js).

No extra method.

TAGLong

The value's type is long long (bignum in js).

No extra method.

TAGFloat

The value's type is float (number in js).

No extra method.

TAGDouble

The value's type is double (nbumer in js).

No extra method.

TAGByteArray

The value's type is array of byte (array of number in js).

There're 5 extra methods:

  • shift()
  • unshift(value)
  • pop()
  • push(value)
  • insert(value, position)

TAGString

The value's type is string.

No extra method.

TAGList

The value's type is array of any Tag instances (array of Tag instances in js).

There're 6 extra methods:

  • shift()
  • unshift(value)
  • pop()
  • push(value)
  • insert(value, position)
  • clean()

TAGCompound

The value's type is object contains any Tag instances.

There're 4 extra methods:

  • setByName(name, value, [replace]): set name child into a certain Tag instance. if replace equals to false, it won't replace an exsiting child. replace defaults to false
  • getNames(): get children's names
  • deleteByName(name): delete a child tag by tag name
  • clean(): clean all children

TAGIntArray

The value's type is array of integer (array of number in js).

There're 5 extra methods:

  • shift()
  • unshift(value)
  • pop()
  • push(value)
  • insert(value, position)

Example

You may refer to test/test.js:

var NBT = require('../nbt');
var nbt = new NBT();
nbt.loadFromZlibCompressedFile('./level.dat', function(err) {
  if(err) return console.error(err);
  var gameRules = nbt.select('').select('Data').select('GameRules');
  console.log(gameRules.getType());
  console.log(gameRules.getTypeId());
  console.log(gameRules.toString());
});

Contribute

You're welcome to pull requests!

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