CODEWITHSUNDEEP
ruby-on-railsmailer
Nikolay Rys
Nikolay Rys

Reputation: 147

Rails, passing an object to mailer

I've got a theoretical question about mailer in Rails. I've heard a pair of times that passing resources directly to mailer is not considerated as good practice. And that is its better simply pass an id to load the object. For example exactly this thing is said in the accepted answer in this question: Rails: Absolutely stumped with delayed_job. Not receiving arguments anywhere

But if it is so, what are the reasons of this prohibition? I can not treat linked question as an exhaustive explanation. Thank you for your suggestions.

Upvotes: 5

Views: 1490

Answers (2)

Anson
Anson

Reputation: 6750

The "Rails Way" is for emails to be delivered later by a background job. That requires saving and restoring (serializing and deserializing) the arguments you pass to the job worker. If an object doesn't have a way to be serialized, then you'll have trouble.

If you are using deliver_later with Active Job, passing a persisted ActiveRecord resource is automatically serialized to a GlobalId for you. You can also pass any of the supported types for arguments, or define a serializer for your object.

As of Rails 7.1, Active Job's supported types for serialization include:

  • String
  • Integer
  • Float
  • NilClass
  • TrueClass
  • FalseClass
  • BigDecimal
  • Symbol
  • Date
  • Time
  • DateTime
  • ActiveSupport::TimeWithZone
  • ActiveSupport::Duration
  • Hash
  • ActiveSupport::HashWithIndifferentAccess
  • Array
  • Range
  • GlobalID::Identification instances

Upvotes: 0

Vadym Chumel
Vadym Chumel

Reputation: 1776

Reason is simple: it's more than 0% probability that your object will be changed between the time you're ordered to send mail and real mailer code execution. Imagine that object you're using will be deleted in process but since you don't have loaded your object at the execution time it'll try to use instance of object that's not exist anymore. I guess now you understand the problem.

Upvotes: 6

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