Here is a quick’n’dirty cheat sheet for basic Active Storage actions.
Attaching
# in model
class Model
has_one_attached :image
has_many_attached :images # for more than one
end
# in controller
@model.image.attach(params[:image])
@model.image.attach(io: File.open("/path/to/file.jpg"), filename: "pic.jpg", content_type: "image/jpg")
Displaying
# in controller for including the attachment when querying
Model.all.with_attached_image
Model.all.with_attached_images
# in view
<%= image_tag @model.image %>
<%= @model.image.filename %>
<%= url_for(@model.image) %>
# variants
<%= image_tag @model.image.variant(resize: "500x500", monochrome: true) %>
Downloading
binary = @model.image.download
# or to create a file
include ActiveStorage::Downloading
tempfile = @model.image.download_blob_to_tempfile # (needs a blob method to be defined)
There is also download_blob_to method that downloads the blob to a given file.
Streaming
# Stream from controller to show in browser (when supported)
response.headers["Content-Type"] = @model.image.content_type
response.headers["Content-Disposition"] = "inline; #{@model.image.filename.parameters}"
@model.image.download do |chunk|
response.stream.write(chunk)
end
# Stream from controller to download
response.headers["Content-Type"] = @model.image.content_type
response.headers["Content-Disposition"] = "attachment; #{@model.image.filename.parameters}"
@model.image.download do |chunk|
response.stream.write(chunk)
end
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