AltManager.js

/**
 * AltManager(Alt: AltClass): undefined
 *
 * > AltManager Util
 *
 * AltManager util allows for a developer to create multiple alt instances in
 * their app. This is useful for building apps that encapsulates an alt instance
 * inside of a outer parent. Popular examples include HipMunk flight search or
 * Google Spreadsheets's multiple sheet tabs. This also allows for caching of
 * client side instance if you need to store a new copy of an alt for each
 * action.
 *
 * Usage:
 *
 * ```js
 * var Alt = require('alt'); // Alt class, not alt instance
 * var altManager = new AltManager(Alt);
 *
 * var altInstance = altManager.create('uniqueKeyName');
 * altInstance.createAction(SomeAction);
 * var someOtherOtherAlt = altManager.create('anotherKeyName');
 * altManager.delete('uniqueKeyName');
 *
 * ```
 */

export default class AltManager {
  constructor(Alt) {
    this.Alt = Alt
    this.alts = {}
  }

  create(altKey) {
    if (this.get(altKey)) {
      throw new ReferenceError(`Alt key ${altKey} already exists`)
    }

    if (typeof altKey !== 'string') {
      throw new TypeError('altKey must be a string')
    }

    this.alts[altKey] = new this.Alt()
    return this.alts[altKey]
  }

  get(altKey) {
    return this.alts[altKey]
  }

  // returns all alt instances
  all() {
    return this.alts
  }

  findWhere(regex) {
    const results = {}
    for (const i in this.alts) {
      if (regex.exec(i) === null) {
        continue
      }

      results[i] = this.alts[i]
    }

    return results
  }

  delete(altKey) {
    if (!this.get(altKey)) {
      return false
    }

    delete this.alts[altKey]
    return true
  }

  getOrCreate(altKey) {
    const alt = this.get(altKey)
    if (alt) {
      return alt
    }

    return this.create(altKey)
  }
}