Request: opt-in mechanism for stylesheets

[tuespetre]

I've got stylesheets that I do not want the polyfill to process. For instance, my project's main stylesheet, and an auxiliary stylesheet with a media attribute for conditional loading. These each have a couple of odd and end rules in it that have properties like inset: auto; or top: 0;, so the polyfill is processing them and generating custom properties for them, even though I know for a fact that these rules will never be relevant to anything I am using anchor positioning with. I want to avoid the re-rendering caused by this, but I would rather not sequester those odd couple of rules into separate stylesheets, they are rather happy just where they are 😄

What I would like to see is a configuration option that puts the polyfill into "opt-in mode", by allowing me to specify an attribute name so that only stylesheets with that attribute name will be processed.

// Still accept the single boolean argument for compatibility:
polyfill(true);

// Also accept an object argument...
polyfill({ 
    updateAnchorOnAnimationFrame: true
});

// ... and add the new option to the object argument for "opt-in mode".
polyfill({
    optInAttribute: 'data-polyfill-anchor'
}); 

// Also allow a global variable to specify the object argument.
window.ANCHOR_POSITIONING_POLYFILL_OPTIONS = {
    updateAnchorOnAnimationFrame: true,
    optInAttribute: 'data-polyfill-anchor'
};

Let me know what y'all think

[jgerigmeyer]

This is released in v0.3.0.