A pattern for promise result access in ES6, allowing decoupled access from multiple modules with a single shared promise. Good for GET APIs.

PromiseSingleton.ts

import { Api } from 'api'

class PromiseAccessSingleton {
  public constructor () { this.init() }

  private dataPromise: Promise<any>

  private init (): void {
    this.dataPromise = Api.GetData().then(data => {
      // Transform `data` if needed...
      return data
    })
  }

  public GetPromise (): Promise<any> {
    return this.dataPromise
  }
    
  public GetProp (): Promise<any> {
    return this.dataPromise.then(data => data.prop)
  }
}

export const PromiseAccess = new PromiseAccessSingleton()