Accept an image via Rails 5 API and Active Storage - ruby-on-rails-5

Question

I am trying to send images to my Rails app and then store them via Active Storage.
I tried Base64 and direct upload and researched for hours but nothing really works.
Can somebody point me to a good way?
My last attempt was to use Base64 like so:
def attach_preview
page = Page.first
content = JSON.parse(request.body.read)
decoded_data = Base64.decode64(content["file_content"].force_encoding("UTF-8"))
begin
file = Tempfile.new('test')
file.write decoded_data
#page.thumbnail = file
filename = "foooo"
page.thumbnail.attach(io: File.read(file), filename: filename)
if page.save
render :json => {:message => "Successfully uploaded the profile picture."}
else
render :json => {:message => "Failed to upload image"}
end
ensure
file.close
file.unlink
end
end
But this results in a "\xAB" from ASCII-8BIT to UTF-8 error.
Dont really care if its Base64 or something else, I just need a way :-)

Answer 1

This works, I use IO directly since ActiveStorage needs it anyway.
def attach_thumbnail
content = JSON.parse(request.body.read.force_encoding("UTF-8"))
decoded_data = Base64.decode64(content["file_content"])
io = StringIO.new
io.puts(decoded_data)
io.rewind
#page.thumbnail.attach(io: io, filename: 'base.png')
#page.save
render json: {
success: #page.thumbnail.attached?,
thumbnail_url: url_for(#page.thumbnail),
page: #page
}
end