ActiveStorage hook after analyze - ruby-on-rails

I have pictures attached to a model. Those pictures are analyzed and the EXIF data is saved as metadata on the ActiveStorage::Blob.
class Foo < ApplicationRecord
has_one_attached :picture
end
There is an attribute on this model that I use for sorting the instances called order_date. This attribute has to be updated with the EXIF time after the blob got analyzed.
Using paperclip, a before_commit callback method was sufficient. With ActiveStorage, I also tried before_save and after_touch but both are not working.
How can I run code right after the ActiveStorage::AnalyzeJob has run successfully?
(I want to avoid monkey-patching ActiveStorage::AnalyzeJob, because it is also performed for other attachments.)
Thanks very much for your help!

I couldn't find anything official. I ended up overriding the analyze job since it is very simple anyways. It looks like below.
#/app/jobs/active_storage/analyze_job.rb
class ActiveStorage::AnalyzeJob < ActiveStorage::BaseJob
def perform(blob)
blob.analyze
blob.attachments.includes(:record).each do |attachment|
if attachment.record_type == 'Content'
record = attachment.record
record.set_file_info
record.save!
end
end
end
end

Related

Rails Active Storage - Keep Existing Files / Uploads?

I have a Rails model with:
has_many_attached :files
When uploading via Active Storage by default if you upload new files it deletes all the existing uploads and replaces them with the new ones.
I have a controller hack from this which is less than desirable for many reasons:
What is the correct way to update images with has_many_attached in Rails 6
Is there a way to configure Active Storage to keep the existing ones?
Looks like there is a configuration that does exactly that
config.active_storage.replace_on_assign_to_many = false
Unfortunately it is deprecated according to current rails source code and it will be removed in Rails 7.1
config.active_storage.replace_on_assign_to_many is deprecated and will be removed in Rails 7.1. Make sure that your code works well with config.active_storage.replace_on_assign_to_many set to true before upgrading.
To append new attachables to the Active Storage association, prefer using attach.
Using association setter would result in purging the existing attached attachments and replacing them with new ones.
It looks like explicite usage of attach will be the only way forward.
So one way is to set everything in the controller:
def update
...
if model.update(model_params)
model.files.attach(params[:model][:files]) if params.dig(:model, :files).present?
else
...
end
end
If you don't like to have this code in controller. You can for example override default setter for the model eg like this:
class Model < ApplicationModel
has_many_attached :files
def files=(attachables)
files.attach(attachables)
end
end
Not sure if I'd suggest this solution. I'd prefer to add new method just for appending files:
class Model < ApplicationModel
has_many_attached :files
def append_files=(attachables)
files.attach(attachables)
end
end
and in your form use
<%= f.file_field :append_files %>
It might need also a reader in the model and probably a better name, but it should demonstrate the concept.
The solution suggested for overwriting the writer by #edariedl DOES NOT WORK because it causes a stack level too deep
1st solution
Based on ActiveStorage source code at this line
You can override the writer for the has_many_attached like so:
class Model < ApplicationModel
has_many_attached :files
def files=(attachables)
attachables = Array(attachables).compact_blank
if attachables.any?
attachment_changes["files"] =
ActiveStorage::Attached::Changes::CreateMany.new("files", self, files.blobs + attachables)
end
end
end
Refactor / 2nd solution
You can create a model concern that will encapsulate all this logic and make it a bit more dynamic, by allowing you to specify the has_many_attached fields for which you want the old behaviour, while still maintaining the new behaviour for newer has_many_attached fields, should you add any after you enable the new behaviour.
in app/models/concerns/append_to_has_many_attached.rb
module AppendToHasManyAttached
def self.[](fields)
Module.new do
extend ActiveSupport::Concern
fields = Array(fields).compact_blank # will always return an array ( worst case is an empty array)
fields.each do |field|
field = field.to_s # We need the string version
define_method :"#{field}=" do |attachables|
attachables = Array(attachables).compact_blank
if attachables.any?
attachment_changes[field] =
ActiveStorage::Attached::Changes::CreateMany.new(field, self, public_send(field).public_send(:blobs) + attachables)
end
end
end
end
end
end
and in your model :
class Model < ApplicationModel
include AppendToHasManyAttached['files'] # you can include it before or after, order does not matter, explanation below
has_many_attached :files
end
NOTE: It does not matter if you prepend or include the module because the methods generated by ActiveStorage are added inside this generated module which is called very early when you inherit from ActiveRecord::Base here
==> So your writer will always take precedence.
Alternative/Last solution:
If you want something even more dynamic and robust, you can still create a model concern, but instead you loop inside the attachment_reflections of your model like so :
reflection_names = Model.reflect_on_all_attachments.filter { _1.macro == :has_many_attached }.map { _1.name.to_s } # we filter to exclude `has_one_attached` fields
# => returns ['files']
reflection_names.each do |name|
define_method :"#{name}=" do |attachables|
# ....
end
end
However I believe for this to work, you need to include this module after all the calls to your has_many_attached otherwise it won't work because the reflections array won't be fully populated ( each call to has_many_attached appends to that array)

Do action after upload file with Active Storage

My model has a has_many_attached :photos.
The first time this model is created, it has 0 photos. If I run photos.attached? I get false.
When the user uploads some files to photos, I need to do some actions, but only the first time. I tried using before_update :if photos.attached?. But I need to know if the user is updating photos specifically.
Is there a way to know if the user is trying to update photos? Or is there a simple way to do this?
There is the dirty? method that you can use
class Post < ApplicationRecord
has_many_attached :photos
before_update :do_whatever, if: -> { photos.dirty? }
def do_whatever
# doing something
end
end
You might also be able to try before_update :do_whatever, if: -> { photos_changed? }
Check callbacks (after_create, after_save, etc) in rails models and options "on: :create" and "update".
Rails has not added the ability to add validations to file attachments. See Issue #31656
Try this approach:
Validate for mime-types:
<%= f.file_field :photos, accept: "image/png,image/gif,image/jpeg', multiple: true %>
You still need to add model validations. See this post Validating the Content-Type of Active Storage Attachments
on how to use a custom validator.
To limit your action to be executed only once, you could add a boolean field to your model and set it to true after your action terminates successfully. Use a before_update as Antarr Byrd suggested to check after each photo is attached to your model.

Callback for Active Storage file upload

Is there a callback for active storage files on a model
after_update or after_save is getting called when a field on the model is changed. However when you update (or rather upload a new file) no callback seems to be called?
context:
class Person < ApplicationRecord
#name :string
has_one_attached :id_document
after_update :call_some_service
def call_some_service
#do something
end
end
When a new id_document is uploaded after_update is not called however when the name of the person is changed the after_update callback is executed
For now, it seems like there is no callback for this case.
What you could do is create a model to handle the creation of an active storage attachment which is what is created when you attach a file to your person model.
So create a new model
class ActiveStorageAttachment < ActiveRecord::Base
after_update :after_update
private
def after_update
if record_type == 'Person'
record.do_something
end
end
end
You normally have created the model table already in your database so no need for a migration, just create this model
Erm i would just comment but since this is not possible without rep..
Uelb's answer works but you need to fix the error in comments and add it as an initializer instead of model. Eg:
require 'active_storage/attachment'
class ActiveStorage::Attachment
before_save :do_something
def do_something
puts 'yeah!'
end
end
In my case tracking attachment timestamp worked
class Person < ApplicationRecord
has_one_attached :id_document
after_save do
if id_document.attached? && (Time.now - id_document.attachment.created_at)<5
Rails.logger.info "id_document change detected"
end
end
end
The answer from #Uleb got me 90% of the way, but for completion sake I will post my final solution.
The issue I had was that I was not able to monkey patch the class (not sure why, even requiring the class as per #user10692737 did not help)
So I copied the source code (https://github.com/rails/rails/blob/fc5dd0b85189811062c85520fd70de8389b55aeb/activestorage/app/models/active_storage/attachment.rb#L20)
and modified it to include the callback
require "active_support/core_ext/module/delegation"
# Attachments associate records with blobs. Usually that's a one record-many blobs relationship,
# but it is possible to associate many different records with the same blob. If you're doing that,
# you'll want to declare with <tt>has_one/many_attached :thingy, dependent: false</tt>, so that destroying
# any one record won't destroy the blob as well. (Then you'll need to do your own garbage collecting, though).
class ActiveStorage::Attachment < ActiveRecord::Base
self.table_name = "active_storage_attachments"
belongs_to :record, polymorphic: true, touch: true
belongs_to :blob, class_name: "ActiveStorage::Blob"
delegate_missing_to :blob
#CUSTOMIZED AT THE END:
after_create_commit :analyze_blob_later, :identify_blob, :do_something
# Synchronously purges the blob (deletes it from the configured service) and destroys the attachment.
def purge
blob.purge
destroy
end
# Destroys the attachment and asynchronously purges the blob (deletes it from the configured service).
def purge_later
blob.purge_later
destroy
end
private
def identify_blob
blob.identify
end
def analyze_blob_later
blob.analyze_later unless blob.analyzed?
end
#CUSTOMIZED:
def do_something
end
end
Not sure its the best method, and will update if I find a better solution
None of these really hit the nail on the head, but you can achieve what you were looking for by following this blog post https://redgreen.no/2021/01/25/active-storage-callbacks.html
I was able to modify the code there to work on attachments instead of blobs like this
Rails.configuration.to_prepare do
module ActiveStorage::Attachment::Callbacks
# Gives us some convenient shortcuts, like `prepended`
extend ActiveSupport::Concern
# When prepended into a class, define our callback
prepended do
after_commit :attachment_changed, on: %i[create update]
end
# callback method
def attachment_changed
record.after_attachment_update(self) if record.respond_to? :after_attachment_update
end
end
# After defining the module, call on ActiveStorage::Blob to prepend it in.
ActiveStorage::Attachment.prepend ActiveStorage::Attachment::Callbacks
end
What I do is add a callback on my record:
after_touch :check_after_touch_data
This gets called if an ActiveStorage object is added, edited or deleted. I use this callback to check if something changed.

upload image to multiple models in rails

I am using carrierwave and Minimagick gem to upload an attachment to S3. Now I want to save the some.pdf in two models(ie, assignment, and message). I give the same parameters in attachment field to save in two tables. But the second table attachment saves blurry. First one gets clear view of attachment.
My controller codes like,
#assignment = Assignment.new(assignment_params)
#message = Message.new
begin
Message.transaction do
asign_att = params[:assignment][:attachment]
#assignment.save!
#message.attachment = asign_att
#message.save!
end
end
My model has,
(in attachment.rb) mount_uploader :attachment, AttachmentUploader
(in message.rb) mount_uploader :attachment, ImageUploader
I want to save same file into two models with clear view. What I want to do? Thanks in advance.
Check in your second table uploader file if you have specified any version or something like that.
With version you can create clones of attachment in different resolutions like this.
version :thumb do
process resize_to_fit 50, 50
end
I would use a callback to do this, something like:
after_commit :assign_to_models
def assign_to_models
...
end
IMHO, I would create an model that has all the carrierwave attachements, and have it belongs both to message and attachement.
I hope this helps

Rails4 and Paperclip 4.0.2 callback turns as infinite loop

I set paperclip to My "Document" model, with a fairly standard config. It works well, but I want to separate the addtitional styles file generation inside a background job (using Resque).
(I would like to stop the creation of the :orginal style to to assign a file manually, but it doesn't seem to be possible)
So, to extract styles inside a background job, I first stop paperclip styles processors.
Then I call the reprocess! inside an after_save callback to generate them.
Doing this put the update action inside an infinite loop, and it is exactly when I call the reprocess!
Here is my Document model (simplified for understanding purpose)
class Document < ActiveRecord::Base
has_attached_file :attachment
before_post_process :stop_process
after_save :process_styles #same result with after_update (since user can only add attachment when updating profile)
# Kill all paperclip styles
#still generate the :orginal style. Block that too to copy it manually from remote folder would be nice
def stop_process
false
end
#call for the generation of the additional styles (:medium, :thumb)
def process_styles
Profile.processDocumentJob(id)
end
#will be a background job
def self.processDocumentJob(id)
document = Document.find(id)
document.attachment.reprocess!
document.save(validate: false)
end
end
Despite my document.save(validate: false), the process loop during the updating.
I tried after_update callback, tweak my code and conditions, with no success.
Thank you in advance for your precious help
I know this is an old question, but happened to me today and solved this way....a bit hacky btw... I'm not proud of my solution. This works in Rails 5.
Added a virtual attribute to my model "skip_callbacks"
Added a method to check if the attribute is true "should_skip_callbacks?"
In my callback added "unless: :should_skip_callbacks?" condition
Before the paperclip reprocess, set the virtual attribute "skip_callbacks" to true
Here's a simplified version of my model:
class Organization < ApplicationRecord
attr_accessor :skip_callbacks
has_attached_file :logo, styles: { header: "380x160>" }
validates_attachment :logo, content_type: {content_type: ['image/png','image/jpg','image/gif']}
after_save :reprocess_logo, unless: :should_skip_callbacks?
def should_skip_callbacks?
self.skip_callbacks
end
def reprocess_logo
self.skip_callbacks = true
self.logo.reprocess!
end
end

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