Avoid duplicated style declarations for detectElementResize

[edulan]

Issue

When using multiple instances of AutoSizer (or mounting and unmounting multiple times) a new style tag is being added to the document head. This is due to detectElementResize vendor library that forces creation every time it's called.

Approaches

Solution 1

Move stylesCreated variable outside of function scope. This way this variable would be set just once independently of how many times function is called.

Solution 2

Identify style tag with an id attribute so we don't duplicate it if it already exists.

Solution 3

Extract style declaration to RV styles.css file.

Current approach

I've opted for using an id as it ensures style tag is created even if it has been previously removed somehow.

Screenshot

Here you can see it in action:

[bvaughn]

Fantastic pull request. So much detail. 😁 Thanks!

[edulan]

You are very welcome :)

[bvaughn]

FYI this optimization has been published as version 8.8.0

[edulan]

Awesome @bvaughn 👏 👏