Thanks Ruby – Array zip fail no comments
After updating rails from 2.0.2 to 2.2.2 on the bit-tech CMS this week I discovered a bug that had cropped up in one of my controllers where I was calling zip to join a a has_many collection with a couple of arrays and iterate through them. The code that was working fine now did something like the following.
>> g.groups.zip([1,2], [3,4]) {|a,b,c| p a.inspect + ‘, ‘ + b.inspect + ‘, ‘ + c.inspect }
“[#<Group id: 1>, 1, 3], nil, nil”
“[#<Group id: 2>, 2, 4], nil, nil”
This is strange, I can no longer access the three elements of the array directly in the block. So I tried the following
>> g.groups.to_a.zip([1,2], [3,4]) {|a,b,c| p a.inspect + ‘, ‘ + b.inspect + ‘, ‘ + c.inspect }
“#<Group id: 1>, 1, 3″
“#<Group id: 2>, 2, 4″
As you can see this solved the problem, but I was confused why there was a difference so I executed…
>> g.groups.class
=> Array
Why when I cast it to an Array, from an Array, is it acting differently? Rails must have done something to the Array class that is returned by the has_many relationship.
