CODEWITHSUNDEEP
javascriptphaser-framework
KevinTheGreat
KevinTheGreat

Reputation: 634

Phaser: Instantiate class by string reference

I am working on a "manager" for selecting what crop shall be placed on a certain plot. Every crop has a completely different design and therefor their own class/object. However instead of writting >40 different lines that will instantiate that class I would like 1 line that simply contains the string that matches the exact name of a class and then run it. That way my code will stay clean. I have tried some stuff but never managed to get it done. Usually resulting in an the following error:

TypeError: this.crop is not a constructor

The code I am attempting to run

export default class CropManager extends Phaser.Group {
  constructor (game, className, plotId) {
    super(game)
    this.x = 0
    this.y = 0
    this.plotId = plotId

    this.className = className
    this.cropHandler(this.className)
  }

  // Defines which class to call

  cropHandler (className) {
    const ActualClass = 'plot' + className

    this.cropclasses = { ActualClass: ActualClass}
    this.crop = this.cropclasses[ActualClass]
    this.classRun = new this.crop(this.game, this.x, this.y, this.plotId)

    this.add(this.classRun)
  }
}

Note every crop their classname = crop+cropname (cropCarrots, cropCows, etc)

Upvotes: 3

Views: 90

Answers (1)

Kamen Minkov
Kamen Minkov

Reputation: 3747

Rethink the way you're storing key-value pairs in this.cropclasses. The way it's done now, it's going to have 'ActualClass' as the key and 'plotNameOfTheClass' (or whatever 'plot' + className produces) as the value, thus, when accessing it later as an array, this.crop comes out undefined since there isn't a 'plotNameOfTheClass' key in the map.

Upvotes: 2

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