hotwired / stimulus

A modest JavaScript framework for the HTML you already have
https://stimulus.hotwired.dev/
MIT License
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Initialize firing twice #215

Closed leastbad closed 5 years ago

leastbad commented 5 years ago

I am seeing Stimulus fire the initialize event twice when I include two instances of a controller in a document. I am under the strong impression that I should see two connect events but only one initialize event per page load.

This happens even without Turbolinks in the picture:

https://codepen.io/pjforde1978/pen/aPVzbR?editors=1011

Apologies if I'm doing it wrong. It seems unlikely that nobody else would have noticed this, and yet I am unable to come up with a simpler example.

javan commented 5 years ago

That's expected. Each controller instance initialize()s once and only once when its element first connect()s, but may connect() and disconnect() multiple times if the element is reconnected to the DOM. See https://stimulusjs.org/reference/lifecycle-callbacks.

Here's a quick demo to help illustrate: https://codepen.io/javan/pen/dwZPmo?editors=1011

leastbad commented 5 years ago

Thank you so much for the insanely fast reply.

For what it's worth, I couldn't find anything in the docs or closed issues that explains this. It might be a good candidate for inclusion in the next round of documentation errata.

javan commented 5 years ago

For what it's worth, I couldn't find anything in the docs or closed issues that explains this.

Did you see https://stimulusjs.org/handbook/managing-state#lifecycle-callbacks-explained and / or https://stimulusjs.org/reference/lifecycle-callbacks?

leastbad commented 5 years ago

Yes, and I just read them again, now, to be sure.

There’s nothing that explicitly spells out that initialize fires once per instantiation. The addition of a short note might save future noobs the confusion I experienced this morning. 🤓

javan commented 5 years ago

There’s nothing that explicitly spells out that initialize fires once per instantiation

screen shot 2018-12-30 at 8 31 25 am
leastbad commented 5 years ago

I understand what we see differently. What I’m trying to explain is that to a newcomer, your use of the word Once instead of the term “Once per instance/occurrence” is just ambiguous enough to be confusing.

The one thing I have is the perspective of an experienced developer doing work with the library for the first time. If you don’t think it’s worth explaining further, no sweat. I really appreciate your explanation regardless.