Why zoom property is in array? Disabling Moving Method? about react-mapbox-gl HOT 6 CLOSED

Yes I know it is an array on purpose, it was a Float before but in order to check for a reference equality on the map component it is required to pass it through an array :

    const didZoomUpdate = (
      this.props.zoom !== nextProps.zoom &&
      nextProps.zoom !== map.getZoom()
    );

In this case if this.props.zoom is [4] and nextProps.zoom is a new array with a Float 4 inside it will break the equality because it does a reference check but it won't in case it is an Float.

If you have a good idea of how to solve it nicely I am happy to discuss of it.

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Maybe I'm not really understand what you're trying to say but as far as I know, if you're just want to comparing it, just use != (i.e. don't use strict equality !==)

const isUpdate = next.zoom != map.getZoom()

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Even with a != it doesn't break the reference equality as if I pass an array because Int, String and Float are primitive types in Javascript

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@Altiano We chose to change this back in version 0.8. It was a quick and easy fix to make sure that the zoom style was updated reliably, every time it's actually changed. Otherwise when the zoom level stays constant the styles are not updated.

The point is, we can't tell whether the zoom has changed, when the number itself has the same value. We can work around this in an easy way like this, by wrapping the number in an array, which is allocated anew each time when you create one (note: [] !== []). This is not exactly fixing the problem, but we didn't see a reason to fix it properly and waste time on it.

To elaborate on equality in JS, === & !== stand for reference equality. It is technically not a strict equality, but to simplify it, it checks whether the values that are being pointed to are the same instance, so technically "in the same point in memory" (not being highly precise, since this doesn't always hold up).

I'm getting a bit off track here, but to further continue == & != are type inferring before checking value equality. Details here: https://dorey.github.io/JavaScript-Equality-Table/

How to disable zoom method? I don't want to use any moving method.

If you want to disable interaction, just pass interaction={false}

cc @alex3165

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This is pulling up some history I appreciate, but I can't follow the reasoning here since you've essentially made a constant expression by strictly comparing an array this will always be true that they do not match, regardless of the values within them.

Is there an original context for this change?

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Everything is explained in the comment above by kitten; and still makes sense.

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