get validations from model

You don't need a plugin for basic needs.

You can do this to get a hash of all validators.

ModelName.validators

If you want to get the validators for a specific field :

ModelName.validators_on(:attribute)

This code yields an array of required fields. It should be adaptable to your needs.

@required_fields = []
ModelName.validators.each do |v|
  @required_fields << v.attributes.first if v.kind == :presence
end

If you add validations dynamically in your models, you can use the instance to list the validations:

product = Product.new
product.singleton_class.validators_on(:price)
#=> [#<ActiveModel::Validations::PresenceValidaton>]

Tested in Rails 5.2.

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