如何在使用ActiveStorage"附加"时跳过Rails验证

Question

我有一个带有徽标的模型作为附件。

当用户上传图像时，应跳过验证name和url验证

validates :logo仍应经过验证

这可能吗？如果可能：如何？

谢谢！

class MyModel < ApplicationRecord
belongs_to :user
has_one_attached :logo do |attachable|
attachable.variant :thumbnail, resize_to_fit: [100, 100]
end
validates :logo, content_type: %w[image/png image/jpg image/jpeg]
# following line should be skipped
validates_presence_of :name, :url # this should be skipped when attaching an image !!!
end
# MyModelController
# That is my current controller action
# PATCH /shops/update_logo
def update_logo
if logo_params[:logo].present?
logo = logo_params[:logo]
if logo && @current_user.my_model.logo.attach(logo)
render json: @current_user, status: :ok
else
render json: @current_user.my_model.errors, status: :unprocessable_entity, error: @current_user.my_model.errors.full_messages.join(', ')
end
else
render json: { error: "no image selected" }, status: :unprocessable_entity
end
end

Answer 1

:on的一些破解

class MyModel < ApplicationRecord
validates :name, :url, presence: true, on: :not_attachment
validates :logo, content_type: %w[image/png image/jpg image/jpeg]
end

my_model.name = my_model.url = nil
my_model.logo.attach(logo)
my_model.valid? # => true

my_model.name = my_model.url = nil
my_model.save(context: :not_attachment)
my_model.valid? # => false