ConditionsConstructor

I hadn’t posted this before because it seemed kind of trivial and silly, but I used it again the other day and decided maybe I should share the joy after all.

Far too often I find myself jumping through hoops building ActiveRecord find conditions arrays dynamically depending on what arguments were passed in to the method. So I cooked up a simple little class to clean that up a bit:

# class to construct conditions for AR queries

# cc = ConditionsConstructor.new('foobar > ?', 7)
# cc.add('blah is not null')
# cc.add('baz in (?)', [1,2,3])
# cc.conditions
# # => ["foobar > ? and blah is not null and baz in (?)", 7, [1, 2, 3]]
class ConditionsConstructor
def initialize(str = nil, *args)
@conditions_strs = str ? [str] : []
@conditions_args = args
end

def add(str, *args)
@conditions_strs << str
@conditions_args += args
end

def conditions
[@conditions_strs.join(' and ')] + @conditions_args
end
end
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