Add MQTT Number (#16115)

* Initial Commit

* sync with #44883

* typo

* sensor -> number

* adds state_topic and availability_mode

* fix

source/_integrations/number.mqtt.markdown

@@ -0,0 +1,135 @@
+---
+title: "MQTT Number"
+description: "Instructions on how to interact with a device exposing a Number through MQTT from within Home Assistant."
+ha_category:
+  - Number
+ha_release: 2020.02
+ha_iot_class: Configurable
+ha_domain: mqtt
+---
+
+The `mqtt` Number platform allows you to integrate devices that might expose configuration options through MQTT into Home Assistant as a Number. Every time a message under the `topic` in the configuration is received, the number entity will be updated in Home Assisant and vice-versa, keeping the device and Home Assistant in-sync.
+
+## Configuration
+
+To enable MQTT Number in your installation, add the following to your `configuration.yaml` file:
+
+```yaml
+# Example configuration.yaml entry
+number:
+  - platform: mqtt
+    command_topic: my-device/threshold
+```
+
+{% configuration %}
+availability:
+  description: A list of MQTT topics subscribed to receive availability (online/offline) updates. Must not be used together with `availability_topic`.
+  required: false
+  type: list
+  keys:
+    payload_available:
+      description: The payload that represents the available state.
+      required: false
+      type: string
+      default: online
+    payload_not_available:
+      description: The payload that represents the unavailable state.
+      required: false
+      type: string
+      default: offline
+    topic:
+      description: An MQTT topic subscribed to receive availability (online/offline) updates.
+      required: true
+      type: string
+availability_topic:
+  description: The MQTT topic subscribed to receive availability (online/offline) updates. Must not be used together with `availability`.
+  required: false
+  type: string
+availability_mode:
+   description: When `availability` is configured, this controls the conditions needed to set the entity to `available`. Valid entries are `all`, `any`, and `latest`. If set to `all`, `payload_available` must be received on all configured availability topics before the entity is marked as online. If set to `any`, `payload_available` must be received on at least one configured availability topic before the entity is marked as online. If set to `latest`, the last `payload_available` or `payload_not_available` received on any configured availability topic controls the availability.
+   required: false
+   type: string
+   default: latest
+command_topic:
+  description: The MQTT topic to publish commands to change the number.
+  required: false
+  type: string
+device:
+  description: "Information about the device this Number is a part of to tie it into the [device registry](https://developers.home-assistant.io/docs/en/device_registry_index.html). Only works through [MQTT discovery](/docs/mqtt/discovery/) and when [`unique_id`](#unique_id) is set."
+  required: false
+  type: map
+  keys:
+    connections:
+      description: 'A list of connections of the device to the outside world as a list of tuples `[connection_type, connection_identifier]`. For example the MAC address of a network interface: `"connections": ["mac", "02:5b:26:a8:dc:12"]`.'
+      required: false
+      type: list
+    identifiers:
+      description: 'A list of IDs that uniquely identify the device. For example a serial number.'
+      required: false
+      type: [list, string]
+    manufacturer:
+      description: The manufacturer of the device.
+      required: false
+      type: string
+    model:
+      description: The model of the device.
+      required: false
+      type: string
+    name:
+      description: The name of the device.
+      required: false
+      type: string
+    sw_version:
+      description: The firmware version of the device.
+      required: false
+      type: string
+    via_device:
+      description: 'Identifier of a device that routes messages between this device and Home Assistant. Examples of such devices are hubs, or parent devices of a sub-device. This is used to show device topology in Home Assistant.'
+      required: false
+      type: string
+icon:
+  description: Icon for the number.
+  required: false
+  type: icon
+json_attributes_template:
+  description: "Defines a [template](/docs/configuration/templating/#processing-incoming-data) to extract the JSON dictionary from messages received on the `json_attributes_topic`."
+  required: false
+  type: template
+json_attributes_topic:
+  description: The MQTT topic subscribed to receive a JSON dictionary payload and then set as number attributes. Implies `force_update` of the current number state when a message is received on this topic.
+  required: false
+  type: string
+name:
+  description: The name of the Number.
+  required: false
+  type: string
+optimistic:
+  description: Flag that defines if number works in optimistic mode.
+  required: false
+  type: boolean
+  default: "`true` if no `state_topic` defined, else `false`."
+qos:
+  description: The maximum QoS level of the state topic. Default is 0 and will also be used to publishing messages.
+  required: false
+  type: integer
+  default: 0
+retain:
+  description: If the published message should have the retain flag on or not.
+  required: false
+  type: boolean
+  default: false
+state_topic:
+  description: The MQTT topic subscribed to receive number values.
+  required: false
+  type: string
+unique_id:
+  description: An ID that uniquely identifies this Number. If two Numbers have the same unique ID Home Assistant will raise an exception.
+  required: false
+  type: string
+{% endconfiguration %}
+
+<div class='note warning'>
+
+Make sure that your topic matches exactly. `some-topic/` and `some-topic` are different topics.
+
+</div>