Source Data and Metadata

This page details the extractable elements from each source. When pulling data into handlers using expressions, you will need to add curly brackets around the expression itself. See Handler Expressions on how this information is extracted.

Kafka

Event Object - Data

There is no pre-existing extractable Kafka event object data, as this is provided by the user.

Event Object - Metadata

The table below explains the extractable metadata fields for Kafka event objects.

Metadata Field	Expression Syntax	Description
topic	{event.metadata.topic}	The topic the source event object came from. Topics are similar to folders in a file system, helping to categorize data.
partition	{event.metadata.partition}	The partition the source event object came from. Partitions are contained within topics, and help improve efficiency by breaking up large chunks of data into smaller partitions.
offset	{event.metadata.offset}	The assigned index that helps keep track of which events have already been consumed, allowing consumers to stop and resume consumption without needing to consume from the beginning.
headers	{event.metadata.headers}	The metadata or context specific to a message, but separate from the actual message payload. Headers are typically stored as key value pairs, and contains information such as the format of the message payload.
key	{event.metadata.key}	The key of the Kafka event object, which determines the partition the event object payload will go to.

HTTP

Event Object - Data

There is no pre-existing extractable HTTP event object data, as this is provided by the user.

Event Object - Metadata

The table below explains the extractable metadata fields for HTTP event objects.

Metadata Field	Expression Syntax	Description
method	{event.metadata.method}	The type of method the HTTP request is using, such as POST and PUT.
headers	{event.metadata.headers}	Additional categorical data about the HTTP request, such as the host or accepted language.
parameters	{event.metadata.parameters}	The parameters the HTTP request abides by to perform a specified method.
scheme	{event.metadata.scheme}	The protocol used for the HTTP request, such as HTTP or HTTPS.
remoteAddr	{event.metadata.remoteAddr}	The IP address of the domain you are performing an HTTP request on.
remoteHost	{event.metadata.remoteHost}	The domain name of the target you are performing an HTTP request on, such as www.inductiveautomation.com.

Alarm

Unlike the event objects above that are set up using an explicit source within the event stream, the alarm event object requires using both the Event Stream Source block and an event listener source.

Event Object - Data

The table below explains the extractable data fields for alarm event objects.

Data Field	Expression Syntax	Description
eventId	{event.data.eventId}	The UUID of the alarm event.
source	{event.data.source}	The qualified path of the entity that generated the alarm event.
displayPath	{event.data.displayPath}	The display path of the alarm.
priority	{event.data.priority}	The priority of the alarm, as an integer. Expected results are: 0 (Diagnostic) 1 (Low) 2 (Medium) 3 (High) 4 (Critical)
priorityReadable	{event.data.propertyReadable}	The priority of the alarm, as a string. Expected results are typically: Diagnostic (0) Low (1) Medium (2) High (3) Critical (4)
eventType	{event.data.eventType}	The condition of the alarm event, as an integer. Expected results are typically: 0 (Active) 1 (Clear) 2 (Acknowledgement) 4 (Alarm Enabled) 5 (Alarm Disabled)
eventTypeReadable	{event.data.eventTypeReadable}	The condition of the alarm event, as a string. Expected results are typically: Active (0) Clear (1) Acknowledgement (2) Alarm Enabled (4) Alarm Disabled (5)
eventFlags	{event.data.eventFlags}	A numeric bitmask flag that provides additional information about the alarm event. See the Alarm Events table for more information on eventFlags.
eventTime	{event.data.eventTime}	The datetime of the alarm event.

Event Object - Metadata

There is no extractable Alarm event object metadata.

Tag Event

Event Object - Data

The table below explains the extractable data fields for tag event objects.

Data Field	Expression Syntax	Description
value	{event.data.value}	The value of the tag event object.
quality	{event.data.quality}	The quality code of the tag that the tag value originates from. See the Quality Code Reference Table for more information on different qualities.
timestamp	{event.data.timestamp}	The timestamp of the tag value.

Event Object - Metadata

The table below explains the extractable metadata fields for tag event objects.

Data Field	Expression Syntax	Description
tagPath	{event.metadata.tagPath}	The tag path of the event object, as a string.
isInitial	{event.metadata.isInitial}	A boolean that returns true if the specified event object's value is the initial value after creating or editing the tag. Follows the same logic as a tag script's initialChange argument.