Stimulus: Initialize firing twice

[leastbad]

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]

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]

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]

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]

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]

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

[leastbad]

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.