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Feature #14059

Updated by nobu (Nobuyoshi Nakada) almost 2 years ago

Consider the following problem - I would like to be able to validate that a JSON string contains all things that can represent positive integers. In this case, it works well with refinements, because I can:

~~~ruby ~~~
class PositiveJSONValidator < ActiveModel::EachValidator
using Module.new {
refine String do
def positive_integer?
match?(/[1-9](?:[0-9])*/)
end
end

refine Integer do
def positive_integer?
self > 0
end
end

refine Float do
def positive_integer?
self == self.to_i
end
end

refine NilClass do
def positive_integer?
false
end
end

refine Array do
def positive_integer?
false
end
end

refine Hash do
def positive_integer?
false
end
end
}

def validate_each(record, attribute, value)
return if valid_positive_json?(value)
record.errors[attribute] << options[:message] || 'is invalid'
end

private

def valid_positive_json?(value)
JSON.parse(value).all? do |key, value|
key.positive_integer? && value.positive_integer?
end
rescue JSON::ParserError
false
end
end
~~~

However, this is kind of annoying because I need to specify each class manually. What I'd love to be able to do is group classes by passing all of the ones that need to be refined in the same way, as in:

~~~ruby ~~~
refine NilClass, Array, Hash do
def positive_integer?
false
end
end
~~~

Is this something that people would consider? It seems like a good use case for refinements because I just want to send a message to an object, so basically I want a default case. I could just refine `Object` Object but that feels wrong, I'd rather get an undefined method exception so that I know something unexpected occurred. If accepted I'd be happy to submit a patch.

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