Are State Classes Required To Extend 'this' and to be declared inside of the static _states() method?

[im-bob-loucans]

I would like to extract state classes into their own file, but the examples all show the state class being declared on the fly and extending this. Is this a required pattern?

[im-bob-loucans]

If its required request that the documentation be updated to reflect this constraint, Thanks.

[g-zachar]

Hi @im-bob-loucans,

while Lightning does enforce some of its patterns, as long as you follow JS semantics you should be fine.

So for example:

{color: 0xff000000}

would be semantically equivalent to:

const COLOR_BLACK = 0xff000000;
...
{color: COLOR_BLACK}

Coming back to states, they mainly depend on class expressions and context resolution of static methods:

static _states() {
    return [
        class MyFirstState extends this {
            _handleEnter() {
                // overwrites root function when we are on this state
            }
        }
    ]
}

which could also be represented like that:

const stateFactory = function(cls) {
    return class MyFirstState extends cls {
        _handleEnter() {
            // overwrites root function when we are on this state
        }
    }
}

static _states() {
  return [stateFactory(this)]
}

So, while following examples is probably safest way to avoid potential issues e.g. with context resolution, it is by no means enforced.

(More extensive example: https://gist.github.com/g-zachar/580094a60c0e27a0396e0745fae6cd2c)

Let me know if this answers your question.

[im-bob-loucans]

Thanks for the info. I followed the factory pattern you provided.