Calls attach_cached, but skips if value is an empty string (this is useful when the uploaded file comes from form fields). Forwards any additional options to attach_cached.

attacher.assign(File.open(...))
attacher.assign(File.open(...), metadata: { "foo" => "bar" })
attacher.assign('{"id":"...","storage":"cache","metadata":{...}}')
attacher.assign({ "id" => "...", "storage" => "cache", "metadata" => {} })

# ignores the assignment when a blank string is given
attacher.assign("")

Uploads given IO object and changes the uploaded file.

# uploads the file to permanent storage
attacher.attach(io)

# uploads the file to specified storage
attacher.attach(io, storage: :other_store)

# forwards additional options to the uploader
attacher.attach(io, upload_options: { acl: "public-read" }, metadata: { "foo" => "bar" })

# removes the attachment
attacher.attach(nil)

Sets an existing cached file, or uploads an IO object to temporary storage and sets it via attach. Forwards any additional options to

attach.¶ ↑

# upload file to temporary storage and set the uploaded file.
attacher.attach_cached(File.open(...))

# foward additional options to the uploader
attacher.attach_cached(File.open(...), metadata: { "foo" => "bar" })

# sets an existing cached file from JSON data
attacher.attach_cached('{"id":"...","storage":"cache","metadata":{...}}')

# sets an existing cached file from Hash data
attacher.attach_cached({ "id" => "...", "storage" => "cache", "metadata" => {} })

Returns whether a file is attached.

attacher.attach(io)
attacher.attached? #=> true

attacher.attach(nil)
attacher.attached? #=> false

Returns the uploader that is used for the temporary storage.

Returns the temporary storage identifier.

Returns whether the file is uploaded to temporary storage.

attacher.cached?       # checks current file
attacher.cached?(file) # checks given file

Sets the uploaded file with dirty tracking, and runs validations.

attacher.change(uploaded_file)
attacher.file #=> #<Shrine::UploadedFile>
attacher.changed? #=> true

Returns whether the attachment has changed.

attacher.changed? #=> false
attacher.attach(file)
attacher.changed? #=> true

Generates serializable data for the attachment.

attacher.data #=> { "id" => "...", "storage" => "...", "metadata": { ... } }

Destroys the attachment.

attacher.file.exists? #=> true
attacher.destroy
attacher.file.exists? #=> false

Destroys the attached file if it exists and is uploaded to permanent storage.

attacher.file.exists? #=> true
attacher.destroy_attached
attacher.file.exists? #=> false

If a new file was attached, deletes previously attached file if any.

previous_file = attacher.file
attacher.attach(file)
attacher.destroy_previous
previous_file.exists? #=> false

Returns attached file or raises an exception if no file is attached.

Saves the given uploaded file to an instance variable.

attacher.file = uploaded_file
attacher.file #=> #<Shrine::UploadedFile>

Deletes any previous file and promotes newly attached cached file. It also clears any dirty tracking.

# promoting cached file
attacher.assign(io)
attacher.cached? #=> true
attacher.finalize
attacher.stored?

# deleting previous file
previous_file = attacher.file
previous_file.exists? #=> true
attacher.assign(io)
attacher.finalize
previous_file.exists? #=> false

# clearing dirty tracking
attacher.assign(io)
attacher.changed? #=> true
attacher.finalize
attacher.changed? #=> false

Returns the attached file.

# when a file is attached
attacher.get #=> #<Shrine::UploadedFile>

# when no file is attached
attacher.get #=> nil

Loads the uploaded file from data generated by Attacher#data.

attacher.file #=> nil
attacher.load_data({ "id" => "...", "storage" => "...", "metadata" => { ... } })
attacher.file #=> #<Shrine::UploadedFile>

Uploads current file to permanent storage and sets the stored file.

attacher.cached? #=> true
attacher.promote
attacher.stored? #=> true

If a new cached file has been attached, uploads it to permanent storage. Any additional options are forwarded to promote.

attacher.assign(io)
attacher.cached? #=> true
attacher.promote_cached
attacher.stored? #=> true

Plugins can override this if they want something to be done in a “before save” callback.

Sets the uploaded file.

attacher.set(uploaded_file)
attacher.file #=> #<Shrine::UploadedFile>
attacher.changed? #=> false

Returns the Shrine class that this attacher’s class is namespaced under.

Returns the uploader that is used for the permanent storage.

Returns the permanent storage identifier.

Returns whether the file is uploaded to permanent storage.

attacher.stored?       # checks current file
attacher.stored?(file) # checks given file

Delegates to Shrine.upload, passing the context.

# upload file to specified storage
attacher.upload(io, :store) #=> #<Shrine::UploadedFile>

# pass additional options for the uploader
attacher.upload(io, :store, metadata: { "foo" => "bar" })

Converts JSON or Hash data into a Shrine::UploadedFile object.

attacher.uploaded_file('{"id":"...","storage":"...","metadata":{...}}')
#=> #<Shrine::UploadedFile ...>

attacher.uploaded_file({ "id" => "...", "storage" => "...", "metadata" => {} })
#=> #<Shrine::UploadedFile ...>

If a file is attached, returns the uploaded file URL, otherwise returns nil. Any options are forwarded to the storage.

attacher.file = file
attacher.url #=> "https://..."

attacher.file = nil
attacher.url #=> nil