quantum-core

# Quantum

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> **This README follows main, which may not be the currently published version**. Here are the
[docs for the latest published version of Quantum](https://hexdocs.pm/quantum/readme.html).

[Cron](https://en.wikipedia.org/wiki/Cron)-like job scheduler for [Elixir](http://elixir-lang.org/).

## Setup

To use Quantum in your project, edit the `mix.exs` file and add `Quantum` to

**1. the list of dependencies:**
```elixir
defp deps do
  [
    {:quantum, "~> 3.0"}
  ]
end
```

**2. and create a scheduler for your app:**
```elixir
defmodule Acme.Scheduler do
  use Quantum, otp_app: :your_app
end
```

**3. and your application's supervision tree:**
```elixir
defmodule Acme.Application do
  use Application

  def start(_type, _args) do
    children = [
      # This is the new line
      Acme.Scheduler
    ]

    opts = [strategy: :one_for_one, name: Acme.Supervisor]
    Supervisor.start_link(children, opts)
  end
end
```

## Troubleshooting

To see more transparently what `quantum` is doing, configure the `logger` to display `:debug` messages.

```elixir
config :logger, level: :debug
```

If you want do use the logger in debug-level without the messages from quantum:

```elixir
config :acme, Acme.Scheduler,
  debug_logging: false
```

If you encounter any problems with `quantum`, please search if there is already an
  [open issue](https://github.com/quantum-elixir/quantum-core/issues) addressing the problem.

Otherwise feel free to [open an issue](https://github.com/quantum-elixir/quantum-core/issues/new). Please include debug logs.

## Usage

Configure your cronjobs in your `config/config.exs` like this:

```elixir
config :acme, Acme.Scheduler,
  jobs: [
    # Every minute
    {"* * * * *",      {Heartbeat, :send, []}},
    # Every 15 minutes
    {"*/15 * * * *",   fn -> System.cmd("rm", ["/tmp/tmp_"]) end},
    # Runs on 18, 20, 22, 0, 2, 4, 6:
    {"0 18-6/2 * * *", fn -> :mnesia.backup('/var/backup/mnesia') end},
    # Runs every midnight:
    {"@daily",         {Backup, :backup, []}}
  ]
```

More details on the