Rails - Sep 2013 - Rails 4 deprecation of in-place edit methods for collection associations

Hi everyone!

For those of you who are not noticed the in-place edit method for 
collection associations are broken in the current rails release - 4.0.0,
and here''s what is cooking in the rails master 
https://github.com/rails/rails/commit/1a40be02113287d9a003f8224e91b9f623857f4b
and this https://github.com/rails/rails/pull/12227

In short: it looks like things like has_many.reject!{}, has_many.select!{}, 
has_many.delete_if{}, has_many.pop etc. will not work as of Rails 4.2.
I tried to get some answers about the motivation of this decision here 
https://github.com/rails/rails/pull/12236 but i failed.

So to the question can someone please explain WHY is this happening?
Where is the "confusion" in the examples above?

PS.
I have read the CHANGELOG - it does not explain the motivation.
And please, I don''t thing that "This behavior was changed by
design. We
choose to not support this in Rails 4.0 and we will not bring it back" and
"The
decision was already made and like I said we will not change it back since 
it introduce more confusion than feature" are answers to my question at
all.

-- 
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To view this discussion on the web visit
https://groups.google.com/d/msgid/rubyonrails-talk/7c850665-fbcb-4741-9de5-b8b3e72dbc3b%40googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

Monkey patch gem to revert to per rails 4 behaviour
http://rubygems.org/gems/rails4-editable-collections

-- 
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To view this discussion on the web visit
https://groups.google.com/d/msgid/rubyonrails-talk/4e405f9a-f08c-4388-ac27-77a6cb0e0f9a%40googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

On Tuesday, 17 September 2013 00:43:15 UTC-5, George Georgiev
wrote:
>
> Hi everyone!
>
> For those of you who are not noticed the in-place edit method for 
> collection associations are broken in the current rails release - 4.0.0,
> and here''s what is cooking in the rails master 
>
https://github.com/rails/rails/commit/1a40be02113287d9a003f8224e91b9f623857f4b
> and this https://github.com/rails/rails/pull/12227
>
> In short: it looks like things like has_many.reject!{}, 
> has_many.select!{}, has_many.delete_if{}, has_many.pop etc. will not work 
> as of Rails 4.2.
> I tried to get some answers about the motivation of this decision here 
> https://github.com/rails/rails/pull/12236 but i failed.
>
> So to the question can someone please explain WHY is this happening?
> Where is the "confusion" in the examples above?
>
 Another related ticket: https://github.com/rails/rails/issues/12140

The problem is that using (for instance) delete_if on a collection removes 
things from the in-memory version but doesn''t persist the changes. It 
*can''t* persist the changes, since the records have been removed from
the
association''s list of records. This is EXACTLY the
"confusion" referenced
in the tickets.

One of your examples in 12236 highlights this issue: these two code 
snippets (in Rails 3 or 4) do not do the same thing:

post.comments.select! { |comment| comment.not_spam? } 
# => filters the array in-memory but does not unlink objects

vs

comments = post.comments.to_a
comments.select! { |comment| comment.not_spam? }
post.comments = comments 
# => unlinks comments that aren''t in the filtered array

--Matt Jones

-- 
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To view this discussion on the web visit
https://groups.google.com/d/msgid/rubyonrails-talk/18f8ba4e-29ec-4c04-863f-1ac857ef4e02%40googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

The justification for this change seems preposterous. Why would anyone 
think that, in the former example, the database has changed? The method 
called there is named "select!".

This sounds like a case of a few people writing fragile code without any 
understanding of what they were doing or the systems they work on, and 
complaining about it. I suggested that a simple bit of documentation would 
solve the problem. It doesn''t seem to make much sense to make this 
particular interface so inconsistent with the rest of ActiveRecord, which 
absolutely allows you to modify objects in memory.

On Monday, September 23, 2013 9:59:52 AM UTC-4, Matt Jones
wrote:
>
>
>
> On Tuesday, 17 September 2013 00:43:15 UTC-5, George Georgiev wrote:
>>
>> Hi everyone!
>>
>> For those of you who are not noticed the in-place edit method for 
>> collection associations are broken in the current rails release -
4.0.0,
>> and here''s what is cooking in the rails master 
>>
https://github.com/rails/rails/commit/1a40be02113287d9a003f8224e91b9f623857f4b
>> and this https://github.com/rails/rails/pull/12227
>>
>> In short: it looks like things like has_many.reject!{}, 
>> has_many.select!{}, has_many.delete_if{}, has_many.pop etc. will not
work
>> as of Rails 4.2.
>> I tried to get some answers about the motivation of this decision here 
>> https://github.com/rails/rails/pull/12236 but i failed.
>>
>> So to the question can someone please explain WHY is this happening?
>> Where is the "confusion" in the examples above?
>>
>
>  Another related ticket: https://github.com/rails/rails/issues/12140
>
> The problem is that using (for instance) delete_if on a collection removes 
> things from the in-memory version but doesn''t persist the changes.
It
> *can''t* persist the changes, since the records have been removed
from the
> association''s list of records. This is EXACTLY the
"confusion" referenced
> in the tickets.
>
> One of your examples in 12236 highlights this issue: these two code 
> snippets (in Rails 3 or 4) do not do the same thing:
>
> post.comments.select! { |comment| comment.not_spam? } 
> # => filters the array in-memory but does not unlink objects
>
> vs
>
> comments = post.comments.to_a
> comments.select! { |comment| comment.not_spam? }
> post.comments = comments 
> # => unlinks comments that aren''t in the filtered array
>
> --Matt Jones
>
-- 
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To view this discussion on the web visit
https://groups.google.com/d/msgid/rubyonrails-talk/95d1558b-1729-4015-93a5-d6d3bd84f57c%40googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

Thank you Matt!!
Now I see my own confusion - I was convinced that these two snippets are 
identical in Rails 3 (Well, they are - JUST in MY case)

When they do the same thing - when the collection contains only new records 
(hence no unlinking required).
In all other cases in-place filtering doesn''t work even in Rails 3 as
you
pointed out.

But I still disagree that dropping the in-place methods (and breaking the 
Collection contract) is the best solution.

Thank you once again for clarifying!!

On Monday, September 23, 2013 4:59:52 PM UTC+3, Matt Jones
wrote:
>
>
>
> On Tuesday, 17 September 2013 00:43:15 UTC-5, George Georgiev wrote:
>>
>> Hi everyone!
>>
>> For those of you who are not noticed the in-place edit method for 
>> collection associations are broken in the current rails release -
4.0.0,
>> and here''s what is cooking in the rails master 
>>
https://github.com/rails/rails/commit/1a40be02113287d9a003f8224e91b9f623857f4b
>> and this https://github.com/rails/rails/pull/12227
>>
>> In short: it looks like things like has_many.reject!{}, 
>> has_many.select!{}, has_many.delete_if{}, has_many.pop etc. will not
work
>> as of Rails 4.2.
>> I tried to get some answers about the motivation of this decision here 
>> https://github.com/rails/rails/pull/12236 but i failed.
>>
>> So to the question can someone please explain WHY is this happening?
>> Where is the "confusion" in the examples above?
>>
>
>  Another related ticket: https://github.com/rails/rails/issues/12140
>
> The problem is that using (for instance) delete_if on a collection removes 
> things from the in-memory version but doesn''t persist the changes.
It
> *can''t* persist the changes, since the records have been removed
from the
> association''s list of records. This is EXACTLY the
"confusion" referenced
> in the tickets.
>
> One of your examples in 12236 highlights this issue: these two code 
> snippets (in Rails 3 or 4) do not do the same thing:
>
> post.comments.select! { |comment| comment.not_spam? } 
> # => filters the array in-memory but does not unlink objects
>
> vs
>
> comments = post.comments.to_a
> comments.select! { |comment| comment.not_spam? }
> post.comments = comments 
> # => unlinks comments that aren''t in the filtered array
>
> --Matt Jones
>
-- 
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To view this discussion on the web visit
https://groups.google.com/d/msgid/rubyonrails-talk/3b603811-8d04-4d3e-a76e-707400ce2d97%40googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.