The Home Assistant Plasmoid can send desktop notifications when entity states change, allowing you to stay informed of important events without keeping the widget open.
Notification System
Notifications are implemented using KDE’s notification system in Notifications.qml:
import org.kde.notification
BaseObject {
Component {
id: notificationComponent
Notification {
componentName: "plasma_workspace"
eventId: "notification"
title: plasmoid.title
iconName: plasmoid.icon
autoDelete: true
}
}
function createNotification(text) {
notificationComponent.createObject(root, { text })?.sendEvent()
}
}
Notification Properties
- Component:
plasma_workspace - Integrates with KDE Plasma notifications
- Title: Uses the plasmoid’s configured title
- Icon: Shows the Home Assistant logo
- Auto-delete: Notifications are automatically removed after display
Enabling Notifications
Notifications are configured per entity using the notify field:
{
"entity_id": "binary_sensor.front_door",
"name": "Front Door",
"icon": "mdi:door",
"notify": true
}
notify: true to enable notifications for an entity’s state changes.
Notification Triggers
Notifications are triggered when an entity’s display value changes. From main.qml:
function updateState(state) {
for(let id in state) {
const itemIdx = items.findIndex(i => i.entity_id === id)
const change = state[id]['+'] // Only changed properties
const item = itemModel.get(itemIdx)
const newItem = new Model.Entity(item, change)
const oldValue = item.value
itemModel.set(itemIdx, newItem)
// Notification check
if (items[itemIdx].notify && oldValue !== newItem.value) {
notifications.createNotification(newItem.name + " " + newItem.value)
}
}
}
Trigger Conditions
A notification is sent when all of these conditions are met:
- The entity has
notify: true in its configuration
- The entity’s display value has changed
- The change comes from a real state update (not initial load)
Notifications are only triggered when the display value changes, not when attributes change. The display value is determined by the entity’s configured attribute or state.
Notification Content
Notifications display the entity name and its new value:
notifications.createNotification(newItem.name + " " + newItem.value)
Content Examples
Binary sensor (door):
Light with brightness:
Temperature sensor:
Outdoor Temperature 23.5 °C
Configuration Examples
Door/Window Sensors
Notify when doors or windows open:
[
{
"entity_id": "binary_sensor.front_door",
"name": "Front Door",
"icon": "mdi:door",
"notify": true
},
{
"entity_id": "binary_sensor.garage_door",
"name": "Garage Door",
"icon": "mdi:garage",
"notify": true
}
]
Motion Sensors
{
"entity_id": "binary_sensor.hallway_motion",
"name": "Hallway Motion",
"icon": "mdi:motion-sensor",
"notify": true
}
Appliance Status
Get notified when appliances finish:
[
{
"entity_id": "sensor.washing_machine",
"name": "Washing Machine",
"icon": "mdi:washing-machine",
"notify": true
},
{
"entity_id": "sensor.dryer",
"name": "Dryer",
"icon": "mdi:tumble-dryer",
"notify": true
}
]
Security Alerts
{
"entity_id": "binary_sensor.smoke_detector",
"name": "Smoke Detector",
"icon": "mdi:smoke-detector",
"notify": true
}
Climate Changes
Monitor significant temperature changes:
{
"entity_id": "sensor.freezer_temperature",
"name": "Freezer",
"icon": "mdi:fridge",
"unit": "°C",
"notify": true
}
For sensors with frequently changing values (like power consumption), notifications can become overwhelming. Use notifications primarily for discrete state changes or significant events.
Display Value vs State
Notifications use the display value, which follows this priority:
- Custom attribute (if configured)
- State with unit
- Empty string
Example: Displaying Brightness Instead of State
{
"entity_id": "light.bedroom",
"name": "Bedroom Light",
"attribute": "brightness",
"notify": true
}
Example: Default State Notification
{
"entity_id": "switch.coffee_maker",
"name": "Coffee Maker",
"notify": true
}
Notification Behavior
Initial Load
Notifications are not triggered during the initial state load:
function initState(state) {
itemModel.clear()
items.forEach((i, idx) => {
const entityData = state[i.entity_id]
itemModel.insert(idx, new Model.Entity(i, entityData))
})
initialized = true
}
updateState function is only called for subsequent changes, preventing notification spam on startup.
Real-Time Updates
Notifications are triggered immediately when Home Assistant sends state updates through the WebSocket connection:
function processData(event) {
if (event.a) initState(event.a) // Initial state, no notifications
if (event.c) updateState(event.c) // Changes, trigger notifications
}
Duplicate Prevention
The value comparison prevents duplicate notifications:
if (items[itemIdx].notify && oldValue !== newItem.value) {
notifications.createNotification(newItem.name + " " + newItem.value)
}
For entities with binary states (on/off, open/closed), every state transition will trigger a notification. For numeric sensors, notifications only occur when the displayed value changes.
System Integration
Notifications appear in the KDE Plasma notification area and:
- Follow system notification settings
- Can be dismissed individually
- Support Do Not Disturb mode
- Are logged in the notification history
- Auto-delete after display (don’t persist)
Best Practices
- Use sparingly: Only enable notifications for important state changes
- Descriptive names: Use clear entity names since they appear in notifications
- Binary sensors: Ideal for door/window sensors, motion detectors
- Discrete states: Better for on/off than continuous numeric values
- Security first: Enable for security-related entities (doors, alarms, smoke detectors)
The autoDelete: true property ensures notifications don’t clutter the persistent notification history. They’re displayed momentarily and then removed automatically.
