# Jackalope

[![Hex version]( "Hex version")](

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`Jackalope` is an opinionated MQTT library that simplifies the use of
[`Tortoise MQTT`]( with cloud IoT

Jackalope aims to make an interface that:

- Ensure that important messages are delivered to the broker, by
  having a local "post office" and tracking the in flight messages,
  and implementing a concept of ttl (time to live) on the messages
  placed in the mailbox; ensuring the "request to unlock the door"
  won't happen two hours later when the MQTT connection finally
  reconnects. This allows Jackalope to accept publish and
  subscription requests while the connection is down.

- Makes it impossible (or at least hard) to do things that AWS IoT
  and other popular services do not support; such as publishing a
  message or subscribing to a topic filter with a greater quality of
  service than allowed, or publishing a message with the retain flag

- Makes it easy to connect to AWS IoT with the correct encryption

Besides this Jackalope aims to provide helpers for local testing,
allowing you to test your application without having a connection to
AWS; Jackalope should take care of that.

## Usage

The `Jackalope` module implements a `start_link/1` function; use this
to start `Jackalope` as part of your application supervision tree. If
properly supervised it will allow you to start and stop `Jackalope`
with the part the application that needs MQTT connectivity.
`Jackalope` is configured using a keyword list, consult the
`Jackalope.start_link/1` documentation for information on the
available option values.

Once `Jackalope` is running it is possible to subscribe, unsubscribe,
and publish messages to the broker; in addition to this there are some
connection specific functionality is exposed, allowing us to ask for
the connection status, and request a connection reconnect.

- `Jackalope.subscribe(topic)` request a subscription to a specific
  topic. The topic will be added to the list of topics `Jackalope`
  will ensure we are subscribed to.

- `Jackalope.unsubscribe(topic)` will request an unsubscribe from a
  specific topic and remove the topic from the list of topics
  `Jackalope` ensure are subscribed to.

- `Jackalope.publish(topic, payload)` will publish a message to the
  MQTT broker;

- `Jackalope.reconnect()` will disconnect from the broker and
  reconnect; this is useful if the device changes network connection.

Please see the documentation for each of the functions for more
information on usage; especially the subscribe and publish functions
accepts options such as setting quality of service and time to live.

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## Installation

If [available in Hex](, the package can be
installed by adding `jackalope` to your list of dependencies in

def deps do
    {:jackalope, "~> 0.1.0"}