Update: watchers.md

[JohnnyEvo]

Add Eager Watchers section to composition side

Description of Problem

When we are in composition option, Eager watchers is not mentioned.

Proposed Solution

Add Eager watchers in composition option.

Additional Information

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[skirtles-code]

Good point, this does need to be covered.

I've provided some feedback on your proposed changes below.

[JohnnyEvo]

Thank you, I considered your review

[skirtles-code]

@JohnnyEvo Thanks for making those changes.

I've just had another read through and I think we now have a problem with the section about watchEffect(). The wording of that section no longer makes sense now that it's preceded by this new section about immediate: true.

Would you like to attempt that rewording yourself? If not then I can give it a go.

[JohnnyEvo]

@skirtles-code I'm not sure I understand what is problematic. Here's my proposal, I'll let you rework it if that doesn't work.

Thanks

[skirtles-code]

The problem is that the watchEffect() section presents watchEffect() as a way to implement eager watchers. It starts with a sentence saying that watch() is lazy and then shows how watchEffect() is the solution to that problem. It doesn't make sense if it comes immediately after a section all about eager watchers. We're presenting two solutions to the same problem without acknowledging the overlap.

With hindsight I don't think the omission of the section about eager watcher is an oversight. I think it was intentional, with the section about watchEffect() being seen as a way to solve the same problem. I still think having a section about eager watchers is a good idea, but we can't have the watchEffect() section framed as a solution to a problem we've just solved in the preceding section.

[JohnnyEvo]

I understand the inconsistency.
We can say that there is an alternative for the lazy watch... but what is the point of having two different ways of doing the same thing? Why choose one or the other?

[skirtles-code]

I've pulled these commits into #2144 and made some changes to the watchEffect() section, so that it doesn't seem quite so out of place.