bug: (Angular 17.2) Model Inputs break modal and popover controllers.

[ntorrey]

bug: (Angular 17.2) Model Inputs break modal and popover controllers.

[liamdebeasi]

Thanks for the report. I'm going to merge this with #28876. The underlying issue is the same, but it looks like my setInput fix in the linked PR isn't enough to resolve the issue. I'll see if there's a better way to resolve this and post updates in the linked thread.

[liamdebeasi]

Hey there! I spoke with the team, and the usage in your demo is incorrect which results in the error. Since myModelInput is already a writeable signal, you don't need to pass another signal when setting componentProps, just the value of the signal is sufficient.

For example, your application passes signal(['one', 'two', 'three']), but you only need to pass ['one', 'two', 'three']. Under the hood we use Angular's setInput API which will take care of correctly updating the signal value while still keeping the data reactive.

[ntorrey]

@liamdebeasi
Interesting! It works, but only partially.
First of all, that's counter-intuitive to what I originally thought since in an angular component, if you want bi-directional reactivity with a model input you have to pass the signal itself and not just the 'unwrapped' value (by calling it with a () at the end.)
Secondly, after testing I noticed that only the first value is pushed back to the original signal in the app.component.
I updated the reproduction which hopefully gets the point across.

[ntorrey]

@liamdebeasi
Sorry for the ping! Just wanted to make sure my comment above doesn't get lost in the shuffle since this issue is marked as closed. Should it be reopened?

[liamdebeasi]

It's possible that we need more clarification from the Angular team, but according to the existing documentation the usage noted in #29013 (comment) is correct.

It does not seem that the controllers have ever supported two way bindings via a single property, so that could be part of the issue here. The controller approach isn't ideal for reactive properties which is why we introduced the inline overlay syntax. You might want to try using an inline modal here instead.

[ntorrey]

Being able to use two-way binding via a controller would be great DX for me, but I get how it is complicated. The inline overlay syntax isn't as handy for modal components that I want to reuse in many different places.