I’ve been using both Active Admin and Delayed::Job for years now and both have served me very well. It’s very common for me to want to display job records in the admin tool and have some extra tools around them such as:

• the ability to mark them all for re-run
• the ability to run one manually (not recommended for production)
• the ability to run them all manually (also not recommended for production)
• an easy way to delete them all
• a good view of the data inside the job

To achieve this, over the years, my admin/delayed_job.rb grew and I took it from project to project. Today I want to share it with you in case you are doing the same:

ActiveAdmin.register Delayed::Job, as: "DelayedJob" do
  collection_action :run_all, method: :post do
    successes, failures = Delayed::Worker.new.work_off
    if failures > 0
      flash[:alert] = "#{failures} failed delayed jobs when running them."
    end
    if successes > 0
      flash[:notice] = "#{successes} delayed jobs run successfully"
    end
    if failures == 0 && successes == 0
      flash[:notice] = "Yawn... no delayed jobs run"
    end
    redirect_to admin_delayed_jobs_url
    I18n.locale = :en # Running delayed jobs can mess up the locale.
  end

  if Rails.env.development?
    collection_action :delete_all, method: :post do
      n = Delayed::Job.delete_all
      redirect_to admin_delayed_jobs_url, notice: "#{n} jobs deleted."
    end
  end

  collection_action :mark_all_for_re_run, method: :post do
    n = Delayed::Job.update_all("run_at = created_at")
    redirect_to admin_delayed_jobs_url, notice: "Marked all jobs (#{n}) for re-running."
  end

  member_action :run, method: :post do
    delayed_job = Delayed::Job.find(params[:id])
    begin
      delayed_job.invoke_job
      delayed_job.destroy
      redirect_to admin_delayed_jobs_url, notice: "1 delayed job run, apparently successfully, but who knows!"
    rescue => e
      redirect_to admin_delayed_jobs_url, alert: "Failed to run a delayed job: #{e.to_s}"
    end
    I18n.locale = :en # Running delayed jobs can mess up the locale.
  end

  action_item do
    links = link_to("Run All Delayed Jobs", run_all_admin_delayed_jobs_url, method: :post)
    links += (" " + link_to("Mark all for re-run", mark_all_for_re_run_admin_delayed_jobs_url, method: :post)).html_safe
    links += (" " + link_to("Delete All Delayed Jobs", delete_all_admin_delayed_jobs_url, method: :post)).html_safe if Rails.env.development?
    links
  end

  index do
    selectable_column
    id_column
    column "P", :priority
    column "A", :attempts
    column("Error", :last_error, sortable: :last_error) { |post| post.last_error.present? ? post.last_error.split("\n").first : "" }
    column(:created_at, sortable: :created_at) { |job| job.created_at.iso8601.gsub("T", " ") }
    column(:run_at, sortable: :run_at) { |post| post.run_at.present? ? post.run_at.iso8601.gsub("T", " ") : nil }
    column :queue
    column("Running", sortable: :locked_at) { |dj| dj.locked_at.present? ? "#{(Time.now - dj.locked_at).round(1)}s by #{dj.locked_by}" : "" }
    actions
  end

  show title: ->(dj) { "Delayed job #{dj.id}" } do |delayed_job|
    panel "Delayed job" do
      attributes_table_for delayed_job do
        row :id
        row :priority
        row :attempts
        row :queue
        row :run_at
        row :locked_at
        row :failed_at
        row :locked_by
        row :created_at
        row :updated_at
      end
    end

    panel "Handler" do
      begin
        pre delayed_job.handler
      rescue => e
        div "Couldn't render handler: #{e.message}"
      end
    end

    panel "Last error" do
      begin
        pre delayed_job.last_error
      rescue => e
        div "Couldn't render last error: #{e.message}"
      end
    end

    active_admin_comments
  end

  form do |f|
    f.inputs("Delayed job") do
      f.input :id, input_html: { readonly: true }
      f.input :priority
      f.input :attempts
      f.input :queue
      f.input :created_at, input_html: { readonly: true }, as: :string
      f.input :updated_at, input_html: { readonly: true }, as: :string
      f.input :run_at, input_html: { readonly: true }, as: :string
      f.input :locked_at, input_html: { readonly: true }, as: :string
      f.input :failed_at, input_html: { readonly: true }, as: :string
      f.input :locked_by, input_html: { readonly: true }
    end

    f.buttons
  end

  controller do
    def update
      @delayed_job = Delayed::Job.find(params[:id])
      @delayed_job.assign_attributes(params[:delayed_job], without_protection: true)
      if @delayed_job.save
        redirect_to admin_delayed_jobs_url, notice: "Delayed job #{@delayed_job} saved successfully"
      else
        render :edit
      end
      I18n.locale = :en # Running delayed jobs can mess up the locale.
    end
  end
end