Modifying association arrays on cloned ActiveRecord objects

Posted by Craig Walker on Stack Overflow See other posts from Stack Overflow or by Craig Walker
Published on 2010-05-30T04:27:47Z Indexed on 2010/05/30 4:32 UTC
Read the original article Hit count: 262

Filed under:

ruby-on-rails

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ruby

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activerecord

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clone

I have an ActiveRecord model class Foo that has_many Bar. I want to clone a Foo (to get duplicates of most of its attributes) and then modify its Bar instances.

This is a problem because cloned ActiveRecord instances share the same associated array; changes to one affect the other.

f1 = Foo.new
b = Bar.new
f1.bars << b
f2 = f1.clone
f2.bars.includes? b    # true
f1.bars.clear
f2.bars.includes? b    # now false

The real problem is that I can't detach the bars arrays from either Foo:

f1.bars << b
f2.bars.includes? b    # true
f2.bars = []
f2.bars.includes? b    # now false
f1.bars.includes? b    # now also false

If I could do that, then I could replace the Bars as I wanted to. However, any change to one Foo seems to affect the other.

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