Files
foundryvtt-smart-doors/lib/libwrapper_shim.js

62 lines
2.0 KiB
JavaScript

// SPDX-License-Identifier: MIT
// Copyright © 2021 fvtt-lib-wrapper Rui Pinheiro
'use strict';
// A shim for the libWrapper library
export let libWrapper = undefined;
Hooks.once('init', () => {
// Check if the real module is already loaded - if so, use it
if(globalThis.libWrapper && !(globalThis.libWrapper.is_fallback ?? true)) {
libWrapper = globalThis.libWrapper;
return;
}
// Fallback implementation
libWrapper = class {
static get is_fallback() { return true };
static register(module, target, fn, type="MIXED", {chain=undefined}={}) {
const is_setter = target.endsWith('#set');
target = !is_setter ? target : target.slice(0, -4);
const split = target.split('.');
const fn_name = split.pop();
const root_nm = split.splice(0,1)[0];
const _eval = eval; // The browser doesn't expose all global variables (e.g. 'Game') inside globalThis, but it does to an eval. We copy it to a variable to have it run in global scope.
const obj = split.reduce((x,y)=>x[y], globalThis[root_nm] ?? _eval(root_nm));
let iObj = obj;
let descriptor = null;
while(iObj) {
descriptor = Object.getOwnPropertyDescriptor(iObj, fn_name);
if(descriptor) break;
iObj = Object.getPrototypeOf(iObj);
}
if(!descriptor || descriptor?.configurable === false) throw `libWrapper Shim: '${target}' does not exist, could not be found, or has a non-configurable descriptor.`;
let original = null;
const wrapper = (chain ?? type != 'OVERRIDE') ? function() { return fn.call(this, original.bind(this), ...arguments); } : function() { return fn.apply(this, arguments); };
if(!is_setter) {
if(descriptor.value) {
original = descriptor.value;
descriptor.value = wrapper;
}
else {
original = descriptor.get;
descriptor.get = wrapper;
}
}
else {
if(!descriptor.set) throw `libWrapper Shim: '${target}' does not have a setter`;
original = descriptor.set;
descriptor.set = wrapper;
}
descriptor.configurable = true;
Object.defineProperty(obj, fn_name, descriptor);
}
}
});