@blakearoberts/ldragon NPM

LDragon

LDragon uses Chevrotain to define a lexer/parser capable of compiling a League of Legends champion spell description template into an abstract syntax tree (AST).

LDragon can run in the browser, checkout the live demo!

Installation

npm

npm install @blakearoberts/ldragon --save

Getting Started

import { ChampionBin, FontConfig, visit } from '@blakearoberts/ldragon';

const f = async <T,>(url: string) => {
  const response = await fetch(url, options)
  if (!response.ok) {
    throw new Error(response.statusText);
  }
  return (await response.json()) as T;
}

const bin = await f<ChampionBin>(
  'https://raw.communitydragon.org/latest/game/data/characters/aatrox/aatrox.bin.json');

const fontConfig = await f<FontConfig>(
  'https://raw.communitydragon.org/latest/game/data/menu/main_en_us.stringtable.json');

const championId = 'Aatrox',
  spellKey = 'Characters/Aatrox/Spells/AatroxPassiveAbility/AatroxPassive',
  tooltip = fontConfig.entries['passive_aatroxpassive_tooltip'];

const ast = visit(championId, spellKey, bin, fontConfig, tooltip);

console.log(ast);

React Example

Checkout the example React app for a simple way to render an LDragon AST to the DOM. This example is built into a static site and hosted via this project's GitHub Pages.

AST Nodes

The AST returned from parsing a spell is comprised of nodes with relationships demonstrated by the following directed acyclic graph:

graph LR;
  D[DescriptionNode]
  TX[TextNode]
  B[BreakNode]
  EL[ElementNode]
  EX[ExpressionNode]
  TP[TemplateNode]

  DV[DataValueIdentifier]
  GC[GameCalculationIdentifier]
  GM[GameCalculationModifiedIdentifier]
  EF[EffectIdentifier]

  C[ConstantValue]
  A[AbilityLevelValue]
  CL[CharLevelValue]
  CB[CharLevelBreakpointsValue]

  subgraph Nodes
  D  --> TX & B & EL & EX & TP
  EL --> TX & EX & TP
  end

  subgraph Identifiers
  EX --> DV & GC & GM & EF
  GC --> DV & EF
  GM --> GC
  end

  subgraph Values
  DV --> C & A
  EF --> C & A
  GC -- part --> C & A & CL & CB
  GM -- multiplier --> C
  end