Approval Workflow

Wait for human approval with timeout fallback.

expense_approvalPending

expense_approval.ex

defmodule MyApp.ExpenseApproval do
  use Durable
  use Durable.Helpers
  use Durable.Wait

  workflow "expense_approval" do
    step :request_approval, fn ctx ->
      result = wait_for_approval("manager",
        prompt: "Approve $#{ctx["amount"]} expense?",
        timeout: days(3),
        timeout_value: :auto_rejected
      )
      {:ok, assign(ctx, :decision, result)}
    end

    branch on: fn ctx -> ctx.decision end do
      :approved ->
        step :process, fn ctx ->
          Expenses.reimburse(ctx["employee_id"], ctx["amount"])
          {:ok, assign(ctx, :status, :reimbursed)}
        end

      _ ->
        step :notify_rejection, fn ctx ->
          Mailer.send_rejection(ctx["employee_id"])
          {:ok, assign(ctx, :status, :rejected)}
        end
    end
  end
end

# Approve externally
Durable.provide_input(workflow_id, "manager", :approved)

The code is the README example. The run is simulated in your browser, with time sped up. For the details, read the waiting guide.