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Diffstat (limited to 'guides/source/active_job_basics.md')
-rw-r--r-- | guides/source/active_job_basics.md | 80 |
1 files changed, 74 insertions, 6 deletions
diff --git a/guides/source/active_job_basics.md b/guides/source/active_job_basics.md index 9fc95954bc..3183fccd4f 100644 --- a/guides/source/active_job_basics.md +++ b/guides/source/active_job_basics.md @@ -120,7 +120,7 @@ production apps will need to pick a persistent backend. ### Backends Active Job has built-in adapters for multiple queuing backends (Sidekiq, -Resque, Delayed Job and others). To get an up-to-date list of the adapters +Resque, Delayed Job, and others). To get an up-to-date list of the adapters see the API Documentation for [ActiveJob::QueueAdapters](http://api.rubyonrails.org/classes/ActiveJob/QueueAdapters.html). ### Setting the Backend @@ -147,7 +147,7 @@ class GuestsCleanupJob < ApplicationJob #.... end -# Now your job will use `resque` as it's backend queue adapter overriding what +# Now your job will use `resque` as its backend queue adapter overriding what # was configured in `config.active_job.queue_adapter`. ``` @@ -162,6 +162,7 @@ Here is a noncomprehensive list of documentation: - [Sidekiq](https://github.com/mperham/sidekiq/wiki/Active-Job) - [Resque](https://github.com/resque/resque/wiki/ActiveJob) +- [Sneakers](https://github.com/jondot/sneakers/wiki/How-To:-Rails-Background-Jobs-with-ActiveJob) - [Sucker Punch](https://github.com/brandonhilkert/sucker_punch#active-job) - [Queue Classic](https://github.com/QueueClassic/queue_classic#active-job) @@ -275,7 +276,7 @@ class GuestsCleanupJob < ApplicationJob end private - def around_cleanup(job) + def around_cleanup # Do something before perform yield # Do something after perform @@ -289,7 +290,7 @@ For example, you could send metrics for every job enqueued: ```ruby class ApplicationJob - before_enqueue { |job| $statsd.increment "#{job.name.underscore}.enqueue" } + before_enqueue { |job| $statsd.increment "#{job.class.name.underscore}.enqueue" } end ``` @@ -338,8 +339,23 @@ UserMailer.welcome(@user).deliver_later # Email will be localized to Esperanto. ``` -GlobalID --------- +Supported types for arguments +---------------------------- + +ActiveJob supports the following types of arguments by default: + + - Basic types (`NilClass`, `String`, `Integer`, `Float`, `BigDecimal`, `TrueClass`, `FalseClass`) + - `Symbol` + - `Date` + - `Time` + - `DateTime` + - `ActiveSupport::TimeWithZone` + - `ActiveSupport::Duration` + - `Hash` (Keys should be of `String` or `Symbol` type) + - `ActiveSupport::HashWithIndifferentAccess` + - `Array` + +### GlobalID Active Job supports GlobalID for parameters. This makes it possible to pass live Active Record objects to your job instead of class/id pairs, which you then have @@ -367,6 +383,39 @@ end This works with any class that mixes in `GlobalID::Identification`, which by default has been mixed into Active Record classes. +### Serializers + +You can extend the list of supported argument types. You just need to define your own serializer: + +```ruby +class MoneySerializer < ActiveJob::Serializers::ObjectSerializer + # Checks if an argument should be serialized by this serializer. + def serialize?(argument) + argument.is_a? Money + end + + # Converts an object to a simpler representative using supported object types. + # The recommended representative is a Hash with a specific key. Keys can be of basic types only. + # You should call `super` to add the custom serializer type to the hash. + def serialize(money) + super( + "amount" => money.amount, + "currency" => money.currency + ) + end + + # Converts serialized value into a proper object. + def deserialize(hash) + Money.new(hash["amount"], hash["currency"]) + end +end +``` + +and add this serializer to the list: + +```ruby +Rails.application.config.active_job.custom_serializers << MoneySerializer +``` Exceptions ---------- @@ -388,6 +437,25 @@ class GuestsCleanupJob < ApplicationJob end ``` +### Retrying or Discarding failed jobs + +It's also possible to retry or discard a job if an exception is raised during execution. +For example: + +```ruby +class RemoteServiceJob < ApplicationJob + retry_on CustomAppException # defaults to 3s wait, 5 attempts + + discard_on ActiveJob::DeserializationError + + def perform(*args) + # Might raise CustomAppException or ActiveJob::DeserializationError + end +end +``` + +To get more details see the API Documentation for [ActiveJob::Exceptions](http://api.rubyonrails.org/classes/ActiveJob/Exceptions/ClassMethods.html). + ### Deserialization GlobalID allows serializing full Active Record objects passed to `#perform`. |