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defmodule JsonSerializer do
  alias Commanded.EventStore.TypeProvider
  alias Commanded.Serialization.JsonDecoder

  @doc """
  Serialize given term to JSON binary data.
  """
  def serialize(term) do
    Jason.encode!(term)
  end

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Publish to an Absinthe GraphQL subscription

Use Absinthe.Subscription.publish/3 to manually publish a mutation after a Commanded Ecto projection has updated a read model in the after_update/3 callback function.

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defmodule OpenAccount do
  defstruct [:account_number, :initial_balance]
  
  @types %{
    account_number: :string,
    initial_balance: :integer      
   }
  
  def validate(params) do
    {params, @types}

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Commanded event handler default error handling

Implement a default event handler error/3 callback function with optional support for retrying failed events before eventually skipping it.

Usage

defmodule MyApp.ExampleHandler do
  use Commanded.Event.Handler, name: __MODULE__
 use Commanded.Event.DefaultErrorHandling, retries: 3

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defmodule CloudWatchReporter do
  use GenServer

  require Logger

  alias ExAws.Cloudwatch

  @namespace "My/App"

  def start_link(args) do

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defmodule Commanded.EventTelemetry do
  @moduledoc """
  A Commanded event handler to produce `:telemetry` events for each recorded
  event.

  It produces the following event:

    - `[:commanded, :event, :published]`
    
  """

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defmodule Commanded.Middleware.Telemetry do
  @moduledoc """
  A Commanded middleware to instrument the command dispatch pipeline with
  `:telemetry` events.

  It produces the following three events:

    - `[:commanded, :command, :dispatch, :start]`
    - `[:commanded, :command, :dispatch, :success]`
    - `[:commanded, :command, :dispatch, :failure]`

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Architecture principles

From Design It! From Programmer to Software Architect by Michael Keeling.

• Partition system and assign responsibilities.
• Decide trade-offs among quality attributes:
  • Performance (response time)
  • Scalability (annual growth)
  • Availability
  • Security

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defmodule AggregateCase do
  @moduledoc """
  Defines a test case to be used by aggregate tests.
  """

  use ExUnit.CaseTemplate

  alias Commanded.Aggregate.Multi

  using opts do

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defmodule JsonbSerializer do
  @moduledoc """
  Serialize to/from PostgreSQL's native `jsonb` format.
  """

  @behaviour EventStore.Serializer

  alias Commanded.EventStore.TypeProvider
  alias Commanded.Serialization.JsonDecoder