electron/lib/browser/utils.ts

38 lines
1.2 KiB
TypeScript

import { EventEmitter } from 'events'
/**
* Creates a lazy instance of modules that can't be required before the
* app 'ready' event by returning a proxy object to mitigate side effects
* on 'require'
*
* @param {Function} creator - Function that creates a new module instance
* @param {Object} holder - the object holding the module prototype
* @param {Boolean} isEventEmitter - whether or not the module is an EventEmitter
* @returns {Object} - a proxy object for the
*/
export function createLazyInstance (
creator: Function,
holder: Object,
isEventEmitter: Boolean
) {
let lazyModule: Object
const module: any = {}
for (const method in (holder as any).prototype) {
module[method] = (...args: any) => {
// create new instance of module at runtime if none exists
if (!lazyModule) {
lazyModule = creator()
if (isEventEmitter) EventEmitter.call(lazyModule as any)
}
// check for properties on the prototype chain that aren't functions
if (typeof (lazyModule as any)[method] !== 'function') {
return (lazyModule as any)[method]
}
return (lazyModule as any)[method](...args)
}
}
return module
}