22 lines
721 B
Ruby
22 lines
721 B
Ruby
class UniqueAmongValidator < ActiveRecord::Validations::UniquenessValidator
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def validate_each(record, attribute, value)
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old_errors = record.errors[attribute].size
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# look for any duplicates at all
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super
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new_errors = record.errors[attribute].size - old_errors
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# do nothing further unless there were some duplicates.
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unless new_errors == 0
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# now look only in the collection we care about.
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dupes = options[:collection].call.where("lower(#{attribute}) = ?", value.downcase)
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dupes = dupes.where("id != ?", record.id) if record.persisted?
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# pop off the error, if it was a false positive
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record.errors[attribute].pop(new_errors) unless dupes.exists?
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end
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end
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end
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