smartsystem/ts/index.ts

import 'typings-global'

import * as path from 'path'
import * as smartq from 'smartq'
import { Objectmap } from 'lik'

class Smartsystem {
  lazyModules = new Objectmap<LazyModule<any>>()

  /**
   * add lazyModule to Smartsystem
   */
  addLazyModule (lazyModuleArg: LazyModule<any>) {
    this.lazyModules.add(lazyModuleArg)
  }
}

// create the internal smartsystem
let smartsystem = new Smartsystem()

/**
 * defines a LazyModule
 */

export type TLoader = 'npm' | 'systemjs'

export class LazyModule<T> {
  name: string
  nameIsPath: boolean
  cwd: string
  whenLoaded: Promise<T>
  loader: TLoader = 'npm'
  private whenLoadedDeferred: smartq.Deferred<T>
  constructor(nameArg: string, cwdArg: string) {
    if (!cwdArg) {
      throw new Error('You must specify a directory to resolve from!')
    }
    this.name = nameArg
    this.cwd = cwdArg
    smartsystem.addLazyModule(this) // add module to smartsystem instance
    this.nameIsPath = /\.\//.test(this.name) // figure out if name is path
    if (this.nameIsPath) {
      this.name = path.join(this.cwd, this.name)
    }
    this.whenLoadedDeferred = smartq.defer<T>()
    this.whenLoaded = this.whenLoadedDeferred.promise
  }

  setLoader (loaderArg: TLoader) {
    this.loader = loaderArg
  }

  /**
   * loads the module
   */
  load (): Promise<T> {
    let done = smartq.defer<T>()
    let loadedModule: T
    if (this.loader === 'npm') {
      loadedModule = require(this.name)
      done.resolve(loadedModule)
    } else if (this.loader === 'systemjs') {
      let systemjs = require('systemjs')
      systemjs.import(this.name).then((m) => {
        loadedModule = m
        this.whenLoadedDeferred.resolve(loadedModule)
        done.resolve(loadedModule)
      }).catch(err => { console.log(err) })
    } else {
      throw Error('loader not supported')
    }
    return done.promise
  }

  /**
   * loads additional lazy modules specified as arguments and returns them in the promise for easy use
   */
  loadAlso (...args: LazyModule<any>[]) {

  }
}