Standard Triggers

This page describes the standard triggers for rules.

openHAB comes with a set of standard triggers. This is a short presentation of these triggers and their configuration. Standard triggers in openHAB are built-in mechanisms that initiate rule execution based on specific events or conditions. They provide a way to automate actions without the need for custom scripting, making them accessible and easy to use.

Trigger Structure

The standard triggers are fundamentally Java classes that implement the required logic to make them do what they should. We identify these triggers using a code that is often called the trigger type. These codes are used as titles for the sections below. To tell the trigger implementation what to react to, triggers can have configuration parameters with predefined names. These configuration parameters and a brief description of what values they expect are listed in the below sections.

timer.DateTimeTrigger

This trigger fires when the system time matches the time or date and time specified by the DateTimeType Item.

Parameter	Description
itemName	The name of the DateTimeType Item.
[timeOnly]	Whether only the time of the Item should be compared, or the date and time. Defaults to false.
[offset]	The offset in seconds to add to the time of the Item state (optional).

timer.GenericCronTrigger

This trigger fires when the system time matches the specified Cron expression (opens new window).

Parameter	Description
cronExpression	The cron expression.

timer.TimeOfDayTrigger

This trigger fires every day at a specified time of day.

Parameter	Description
time	The time in "hh:mm" format.

core.ItemCommandTrigger

This trigger fires when the specified Item receives a Command.

Parameter	Description
itemName	The name of the Item.
[command]	The Command (optional).

core.ItemStateUpdateTrigger

This trigger fires when the specified Item's State is updated, even if the new value is equal to the old value.

Parameter	Description
itemName	The name of the Item.
[state]	The State (optional).

core.ItemStateChangeTrigger

This trigger fires when the specified Item's State changes.

Parameter	Description
itemName	The name of the Item.
[previousState]	The previous State (optional).
[state]	The State (optional).

core.GroupCommandTrigger

This trigger fires when a member of the specified item group receives a Command.

Parameter	Description
groupName	The name of the GroupItem.
[command]	The Command (optional).

core.GroupStateUpdateTrigger

This trigger fires when the State of a member of the specified item group is updated, even if the new value is equal to the old value.

Parameter	Description
groupName	The name of the GroupItem.
[state]	The State (optional).

core.GroupStateChangeTrigger

This trigger fires when the State of a member of the specified item group changes.

Parameter	Description
groupName	The name of the GroupItem.
[previousState]	The previous State (optional).
[state]	The State (optional).

core.ThingStatusUpdateTrigger

This trigger fires when the specified Thing's status is updated, even if the new status is equal to the old status.

Parameter	Description
thingUID	The thingUID.
[status]	The ThingStatus (optional).

core.ThingStatusChangeTrigger

This trigger fires when the specified Thing's status changes.

Parameter	Description
thingUID	The thingUID.
[previousStatus]	The previous ThingStatus (optional).
[status]	The ThingStatus (optional).

core.ChannelEventTrigger

This trigger fires when the specified trigger channel receives an event.

Parameter	Description
channelUID	The ChannelUID of the Channel.
[event]	The Channel trigger Event (optional).

core.GenericEventTrigger

This trigger fires when a matching Event appears on the event bus.

Parameter	Description
[topic]	The topic to match, as a file-system style glob (*, **, ?, and {} operators). Example filters: Item events: openhab/items/*/ Channel events: openhab/channels/*/triggered Thing events: openhab/things/**
[source]	A string that represents the entity that caused the event.
[types]	ItemCommandEvent, ItemStateEvent, ItemStateChangedEvent, GroupItemStateChangedEvent, ItemAddedEvent, ItemRemovedEvent, ThingAddedEvent, ThingRemovedEvent, ThingStatusInfoChangedEvent, ThingStatusInfoEvent, ThingUpdatedEvent, etc. A non-exhaustive list can be found in the Javadocs (opens new window).
[payload]	A regular expression (opens new window) to match against the actual event data.

core.SystemStartlevelTrigger

This trigger fires when the system has reached the specified start level.

Parameter	Description
startlevel	The system StartLevel.

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