2020-04-07-yil-rails-validators-dont-change-type
source link: https://github.com/tamouse/swaac/blob/master/posts/2020/04/2020-04-07-yil-rails-validators-dont-change-type.md
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YIL: Rails validators don't change parameter type
2020-04-07T09:04
rails
validation
type
params
So I figured this out a while ago, but seems that I forgot to write it down, hence "YIL" - Yesterday I Learned.
I was working with a numeric parameter in Rails, that needed to be a non-negative interger, less than a maximum level. A pretty simple validator :
validates_numericality_of :age,
:only_integer,
greater_than_or_equal_to: 0,
less_than_or_equal_to: MAX_AGE
The validators work with age
regardless of whether it's a number or string; coming in via a parameter from the controller, it will be a string. In a Rails model, this isn't much of an issue since the variable gets converted to whatever is the right type when the record is persisted.
The case I was working with wasn't an ActiveRecord however, but just an ActiveModel service object.
In order to fix this for the object model, I used an after_validation
callback to transform the variable:
def recast_attributes age = age.to_i end
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