Monday, July 2, 2018
On Tue, Jul 3, 2018 at 7:03 AM, Phil Edelbrock <edelbrp@gmail.com> wrote:
=> "my_items">> a = MyItem.table_name
>> b = a
=> "my_items"
>> c = b
=> "my_items"
>> d = c
=> "my_items"
var references object.
at this point, all vars a,b,c,d points to MyItem.table_name
>> d << ", other_items"
=> "my_items, other_items" <---- Same result! Looks right.
>> c
=> "my_items, other_items"
>> MyTable.table_name
=> "my_items, other_items" <--- Oh noes, the result was inherited all the way down to the table_name of the model!
Now the MyItem model is borked until the app is restarted.
The malformed 'from' clause was a bit of a red herring and that was easily resolved, btw. (A 'join(', ')' was skipped because the construction of the from-clause was a string not an array any more in our code.)
The '<<' method appears to work the same as the String method ".concat(something)" . It also makes all other variables inherit the same value.
it does more, just be careful since it flattens.
(from ruby core)
=== Implementation from Array
------------------------------------------------------------------------
ary.concat(other_ary1, other_ary2,...) -> ary
------------------------------------------------------------------------
Appends the elements of +other_ary+s to self.
[ "a", "b" ].concat( ["c", "d"] ) #=> [ "a", "b", "c", "d" ]
[ "a" ].concat( ["b"], ["c", "d"] ) #=> [ "a", "b", "c", "d" ]
[ "a" ].concat #=> [ "a" ]
Another possible solution is to use '.dup', for what it is worth:
indeed
>> d = c.dup
=> "my_items"
>> d << ", other_items"
=> "my_items, other_items"
>> c
=> "my_items"
I hope this helps somebody if they run into a similar problem! (I don't claim this is a Ruby bug or such, just perhaps not very well documented feature.)
(from ruby core)
=== Implementation from Array
------------------------------------------------------------------------
ary << obj -> ary
------------------------------------------------------------------------
Append---Pushes the given object on to the end of this array. This
expression returns the array itself, so several appends may be chained
together.
[ 1, 2 ] << "c" << "d" << [ 3, 4 ]
#=> [ 1, 2, "c", "d", [ 3, 4 ] ]
fwiw, you're function/method seems to do a lot of things. maybe best to create a unit test for it, no?
Phil
kind regards
,--botp
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