Data Seeding: Create fake image data using image URLs

[rayjasson98]

Hi, during data seeding, I want to create fake image_data attributes from image URLs. I can get a set of random image URLs from Faker generators like Faker::LoremFlickr. These are my requirements:

1. Create image_data object from image URLs and save it together with the model.
2. Do not trigger any upload process or backgrounding promote block when seeding fake image data.

According to the docs, I can build an <attachment>_data object like this:

  {
    id: "...",
    storage: "...",
    metadata: {
      size: "...",
      filename: "...",
      mime_type: "..."
    }
  }

However, the problem is there is no way to create the object from image URLs where I can retrieve the stored image using the <attachment>_url method. I know it does not make sense to have this behaviour in production, but is there a way I can simulate this behaviour in order for me to seed image data quickly?

Thank you.

[jrochkind]

Having just done something similar, i think what you want is:

attacher.set(data_hash)

For instance, on an ActiveRecord model with an image shrine attribute,

model.image_attacher.set( data_hash )

Let me know if it does what you want?

[rayjasson98]

Thanks for your hints! Please see my reply below.

[rayjasson98]

Unfortunately, calling model.image_attacher.set(image_data_hash) gave me this error:

bundle/gems/shrine-3.4.0/lib/shrine/attacher.rb:314:in `file=': expected file to be a Shrine::UploadedFile or nil, got ...

While digging into the source code, I found that I need to instantiate a Shrine::UploadedFile object with the image_data_hash. Also, I need a gem called shrine-url to create a fake storage that allows me to assign image data by custom URLs.

The full steps are shown below:

1. Add gem "shrine-url", "~> 2.4" to your Gemfile.
2. In your config/initializers/shrine.rb, add the following lines:

   require "shrine/storage/url"
   
   Shrine.storages = {
     test: Shrine::Storage::Url.new,
     ...
   }

3. Create fake image_data attribute like this:

   image_data = Shrine::UploadedFile.new({
     id: "your image url",
     storage: "test",
     metadata: {}
   })

4. Save the model with the image_data attribute:

   model.image_attacher.set(image_data)
   mode.save

You can now retrieve the image by calling model.image_url. Also, I think it would be nice if someone can include this in the documentation.

[jrochkind]

oops, that's exactly right, I accidentally forgot that uploaded file step, sorry! Another way to do that is:

model.image_attacher.set(Shrine.uploaded_file(image_data))