Class: ContentTypeValidator

Inherits:
ActiveModel::EachValidator
  • Object
show all
Defined in:
app/validators/content_type_validator.rb

Overview

Custom validator for attachments’ content types

Examples:


-> validates :image, content_type: :image
-> validates :image, content_type: [:jpg, :webp]
-> validates :image, content_type: [:image, :pdf]
-> validates :image, content_type: { in: :image, message: 'must be a valid image' }

Constant Summary collapse

EXPANSIONS = 
{
  image:        %i[png jpeg jpg jpe pjpeg gif bmp svg webp],
  document:     %i[text txt docx doc xml pdf csv],
  calendar:     %i[ics],
  spreadsheet:  %i[xlsx xls],
  video:        %i[mpeg mpg mp3 m4a mpg4 aac webm mp4 m4v],
}.freeze

Instance Method Summary collapse

Instance Method Details

#validate_each(record, attribute, value) ⇒ Object 



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# File 'app/validators/content_type_validator.rb', line 20

def validate_each(record, attribute, value)
  # Support for optional attachments
  return unless value.present? && value.attached?

  keys   = EXPANSIONS.keys
  values = EXPANSIONS.values.flatten
  options = instance_values["options"]
  message = options.try(:[], :message) || "must have a valid content type"
  types = options[:with] || options[:in]

  # Ensure array and ensure symbols
  types = [types].flatten.compact.map(&:to_sym)

  allowed_types = []
  types.each do |types|
    if types.in?(keys)
      allowed_types << EXPANSIONS[types]
    elsif types.in?(values)
      allowed_types << types
    else
      raise("unknown content_type types: #{types}")
    end
  end
  allowed_types = allowed_types.flatten.map(&:to_sym).uniq

  # Make sure all attachments have this extension
  Array(value).each do |attachment|
    next if allowed_types.include?(attachment.filename.extension.to_sym)
    record.errors.add(attribute, message)
  end

end