use:popper action (instead of component based API)

[Federico Zivolo]

The existing <Popper /> component doesn't feel right, it does absolutely nothing, if not allow the consumers to pass props down and retrieve the result.

The README example could be written as follows and everything would still work:

<Popper
  reference={referenceElement}
  popper={popperElement}
  options={popperOptions}
  bind:styles
  bind:attributes
/>

<button bind:this={referenceElement}>Reference Element</button>
<div
  bind:this={popperElement}
  class="tooltip"
  style={css(styles.popper)}
  {...attributes.popper}>
  Popper Element
  <div bind:this={arrowElement} class="arrow" style={css(styles.arrow)} />
</div>

A cleaner approach could be the use:action API.

<script>
  let styles = {};
  let attributes = {};
</script>

<button
  use:popper={{ popperElement, options }}
  on:popperUpdate={evt => {
    styles = evt.detail.styles;
    attributes = evt.detail.attributes;
  }}
>
  Reference Element
</button>

Here's a basic example:
https://codesandbox.io/s/trusting-butterfly-704gd?file=/popperAction.js

Thoughts?

[Bryan Lee]

I just found out about this issue, and I’ve actually just published a package that uses two actions to attach Popper!

https://github.com/bryanmylee/svelte-popperjs

The idea is to wrap both actions in an object such that there is some shared state, then attach Popper there.

For my package, I have a createPopperActions function which returns two functions – refAction and popperAction, that are used on the reference and popper element.

popperAction takes the popper options config object, and while it doesn’t emit any event to update styles or attributes yet, that is definitely a possibility.

Perhaps that could be of some help!

[Bryan Lee]

<script>
  import { createPopperActions } from ‘svelte-popperjs’;
  const [ popperRef, popperContent ] = createPopperActions();
</script>

<button use:popperRef>
  Reference Element
</button>
<div use:popperContent={{ placement: ‘right’ }}>
  Popper Element
</div>

Here’s an example of how my package is used.