CarrierWave::FormNotMultipart error when creating

问题:

I have a model that has a image column. I am using CarrierWave to upload images (I am following this rails cast to do this.

Now, I want to create some default records using seed.rb file but I have failed to provided correct parh/url to the images.

So, I have images in List item app/public/images/ folder and this is the code from the seed.rb file:

gems = {

    test1: {

        name: 'test1',
        description: 'test1',
        image: '/public/images/test1.png',
    },

    test2: {

        name: 'test2',
        description: 'test2',
        image: '/public/images/test2.png'
}

gems.each do |user, data|

  gem = DemoGem.new(data)

  unless DemoGem.where(name: gem.name).exists?
    gem.save!
  end
end

And I am getting the following error when I run rake db:seed command:

CarrierWave::FormNotMultipart: You tried to assign a String or a Pathname to an uploader, for security reasons, this is not allowed.

Could anyone tell how to provided correct url to the images?

回答1:

Presuming that your Gem model has the image field as a Carrierwave uploader (that is, you've got mount_uploader :image, ImageUploader or similar in your Gem model), you can assign a ruby File object to your image attribute, not a string. Something like this:

gem = Demogem.new(data)
image_src = File.join(Rails.root, "/public/images/test2.png")
src_file = File.new(image_src)
gem.image = src_file
gem.save

---

In your overall code, you could either change your seed data (so your image property in your hash was set to File.new(File.join(Rails.root, "/public/images/test1.jpg")) or change the way you construct your new records so it doesn't use the image by default:

gems.each do |user, data|
    gem = DemoGem.new(data.reject { |k, v| k == "image" })
    gem.image = new File(File.join(Rails.root, data["image"]))

    unless DemoGem.where(name: gem.name).exists?
        gem.save!
    end
end

The CarrierWave wiki has some documentation on this, but it's not very extensive.

回答2:

This is what I do on my case:

["Sublime Text 3", "Internet Explorer"].each do |title|
  unless Post.exists?(title: title)
    post = Post.create!(title: title,
                        subtitle: "Subtitle of the #{title}",
                        content: "A sample post of the content about #{title}",
                        author: User.first)
    post.attachments_attributes = [file: Rails.root.join("spec/fixtures/photo.jpg").open]
    post.save!
  end
end

回答3:

A smart way to put the content in seed file like this

Rails.root.join("#{Rails.root}/app/assets/images/image_a.jpg")