textarea - Weird behavior on event (Html.Events.on) -

i'm making "fluid" textarea, resizes it's height according it's content. i'm trying implement this script. have following code: https://ellie-app.com/vjtvm6yrkwa1/4

the issue when increasing, works no problem, when trying decrease height, doesn't work expected.

how reproduce issue:

1. the textarea comes default text. if click on textarea, resize it's height content.
2. delete half of text or entire text.
3. click in textarea again. expected behaivor should resize it's height again,recuding it's height, doesn't. either nothing or reduces height little (making have click lot of times until height ok)

i think it's related virual-dom preventing scrollheight change, cache (performance-wise), it's guess.

what problem?

ps. when trying use other kind of events, "input" or "change", issue occurs.

edit 4/20: ilias on slack channel linked this: https://ellie-app.com/h5x9dc4j9ba1/0 (ellie of pure elm autoexpannding text area)

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i doubt it's issue w/ decoders.

notice in js example when textarea content changes 2 things done new height:

-- set textarea..height auto
-- textarea..scrollheight.

without first setting auto js example, too, exhibits behavior you're seeing in elm example.

now notice sequence of events in elm example:

1-- remove lines of text
2-- click textarea; calculates current height (before setting height auto)
3-- ... dispatches heightchange
4-- ... dispatches autoheight, updateheight old height step 2

thus, again, doubt it's issue w/ decoder. check, see following (quick/dirty) ellie -- toggles height between auto , calculated height, , you'll see correct height calculated every other click: https://ellie-app.com/wwbdfdvhypa1/0

(aside: elm may coalesce values queued same animation frame, dunno w/o looking @ source, that's still beside point here.)