Feature #14059
closedRefine multiple classes in one call
Description
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:
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:
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
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.
Updated by rrroybbbean (RRRoy BBBean) about 7 years ago
On Thu, 2017-10-26 at 17:30 +0000, kevin.deisz@gmail.com wrote:
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 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.
Yes. This is awesome and excellent. For curiosity, why not enclose the
classes in []
?
Updated by duerst (Martin Dürst) about 7 years ago
I'm really not sure about this. If we need this for refinements, why don't we have for classes in the first place? E.g.:
class Foo, Bar, Baz
def positive_integer?
false
end
end
It seems strange to introduce syntactic sugar just for refinements.
Updated by shevegen (Robert A. Heiler) about 7 years ago
Perhaps it could be an Array
input for Module#refinements
?
There he could perhaps specify the classes that are to be
modified. So the above example would then be:
refine [NilClass, Array, Hash] do
def positive_integer?
false
end
end
instead.
http://ruby-doc.org/core-2.4.2/Module.html#method-i-refine
But I know too little about refinements and also too little
about what Kevin wants to achieve, aside from him using
less syntax for batch-modification, which I think is
understandable. :)
Updated by jeremyevans0 (Jeremy Evans) about 7 years ago
I think the natural way to handle this is a loop:
[NilClass, Array, Hash].each do |c|
refine c do
def positive_integer?
false
end
end
end
Because of that I don't think we need new syntax to support this.
Updated by nobu (Nobuyoshi Nakada) about 7 years ago
- Description updated (diff)
And also a Module
.
using Module.new {
m = Module.new {
def positive_integer?
false
end
}
[NilClass, Array, Hash].each {|k| refine(k) {include m}}
}
Updated by kddnewton (Kevin Newton) over 6 years ago
I agree with the points above, so this issue can be closed (or someone can teach me how to close these, I'm not entirely sure how).
Updated by jeremyevans0 (Jeremy Evans) about 3 years ago
- Status changed from Open to Closed