Update Rails Guides about :autosave option

[chumakoff]

Call attention to the fact, that If the :autosave option is not set (neither true nor false), it is not the same as false: only new loaded members are saved.

According to this

rails/activerecord/lib/active_record/autosave_association.rb

Line 21 in e533ee7

# Note that <tt>autosave: false</tt> is not same as not declaring <tt>:autosave</tt>.

[rails-bot]

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[eileencodes]

Hey @chumakoff thanks for the PR!

I think this change is confusing for readers. I think it's not clear what is not the same as false. What do you think about combining the original docs you linked to like this:

If you set the :autosave option to true, Rails will save any loaded members and destroy members that are marked for destruction whenever you save the parent object. Setting :autosave to false is not the same as not setting the :autosave option. When the :autosave option is not present then new association records are saved but the updated association records are not saved.

[chumakoff]

@eileencodes Hi! I agree with you. But I have one more thing to suggest. In the guide there is almost everywere "associated objects"wording. Sometimes it is "association members". In this paragraph it is "members" in the first sentence (I think it's not very clear what members), and "association records" further. So, let's use the same wording for uniformity and definiteness.

If you set the :autosave option to true, Rails will save any loaded association members and destroy members that are marked for destruction whenever you save the parent object. Setting :autosave to false is not the same as not setting the :autosave option. If the :autosave option is not present, then new associated objects will be saved, but updated associated objects will not be saved.

What do you think?

[eileencodes]

@chumakoff sounds good. Please update the PR and squash your commits. Thanks for working on this!.

[chumakoff]

@eileencodes Done. Thank you for your cooperation! )