A Careless Mistake

EDIT

I made a careless mistake in my code. There is nothing wrong with this in either of these examples.

I forgot to make the item in example 1 a container. Then, I made a mountain (or at least a small hill) out of a mole hill.

Pixie explains here

If you'd like to possibly learn from my mistakes, read on. Just ignore what I'm saying about this in this post!


(OLD POST TITLE: Quest 6: Using the JS this Keyword to Target the Item in Function Attributes of Clone Prototype Items)

Bad Example

this being used in this code will cause an error when examining a clone:

createItem("grocery_sack", {
	loc:"cloneRoom",
	examine: function(){
		msg("A paper grocery sack.")
		let stuff = this.listContents()
		msg("The sack currently contains: ")
		msg(stuff)
	}
})

Gameplay

When I examine a clone of this object, this happens:

image


image


Good Example

this will work fine when examining a clone if we code it like this:

createItem("grocery_sack", CONTAINER(false), {
	loc:"cloneRoom",
})

w.grocery_sack.examine = function() {
		msg("A paper grocery sack. ")
		let stuff = this.listContents()
		msg("The sack currently contains: ")
		msg(stuff)
}

Gameplay

image


I thought I knew the reason it throws an error when attempting to examine a clone of the object in the first example, but I quickly realized that I have not a clue whilst attempting to type up an explanation.


Note that I'm not saying this is a bug (or even an issue). I'm just sharing the method I found that works.


Also note that you shouldn't call cloneObject until the game has loaded. (Calling it from settings.setup works perfectly for me.)


Summary

So:

  • Watch out when using this!
  • Calling createItem after the game has loaded is bad.
  • Calling cloneObject before the game has loaded is bad.

REFERENCE

https://github.com/ThePix/QuestJS/wiki/Creating-objects-on-the-fly


This will be a kicking yourself one, I am afraid. The problem with the first one is it is not a container. this exists, but has no listContents function. This works fine.

createItem("grocery_sack1", CONTAINER(false), {
	loc:"lounge",
	examine: function(){
		msg("A paper grocery sack.")
		let stuff = this.listContents()
		msg("The sack currently contains: ")
		msg(stuff)
	}
})

A good way to diagnose issues like this is to add a console.log that tells you what this actually is.

createItem("grocery_sack", {
	loc:"cloneRoom",
	examine: function(){
		msg("A paper grocery sack.")
                console.log(this)
		let stuff = this.listContents()
		msg("The sack currently contains: ")
		msg(stuff)
	}
})

You can then see if it is undefined, and if not, check its attributes. What is its name? What is listContents?


Ha ha!

I should have realized it was probably operator error when I couldn't explain it. I woke up this morning wondering what the difference really was between the two examples, and it was a careless mistake. (I make those frequently.)

Huh. This is the second time this week I've posted something here when I should have done more research first. Life lesson learned: slow my happy ass down!


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