Every time an editor changes data in UNE for ArcGIS, they are performing an operation. Each operation can send many Add, Update and Delete row level changes to the database or server. Triggers are a capability that allow you to add further Add, Update and Delete operations to the existing UNE for ArcGIS operations.

Triggers are useful for many workflow scenarios. For example:

Log Tables:	If you wish to write details about the user’s actions to a log table.
Exclusion Zones:	If you want to automatically generate exclusion zones as features, around any features the user is editing.
Companion Features:	If you want to create additional features at the intersection or vertices of the feature the editor has just changed.

Triggers allows for all of these types of workflow, and more. However it is capability which must be configured using scripts.

Adding a trigger

1. Click on Data Rules Editor to switch to the rules view.
2. In the Data Rules menu click Data to switch to spatial rules editor.
3. Click the layer you want to add a trigger to.
4. Click on the Triggers tab.
   
5. Click the Add button to add a new trigger.
   
6. Give the trigger a Name.
7. Select the type of Trigger event.
8. Select the type of Data changes to apply.
9. Select or search for the layer to apply the changes to.
10. Configure the Script to define the features that are to be added, deleted or modified.
11. Click OK.

Types of trigger event

Triggers fire in response to data changes in the layer for which the trigger is being configured.

Each trigger will respond to a single type of trigger event. When the event occurs, the data change script/behaviour will be executed.

Row level events

Row insert	Will fire once for each individual feature added to the layer.
Row update	Will fire once for each individual feature updated in the layer. For example a change to the geometry of a feature and/or to its attributes.
Row delete	Will fire once for each individual feature deleted from the layer.

Data level events

Data level events detect when changes happen if any data is added/edited/deleted in a layer.

Post all changes	Will fire once per operation. It will have access to all the features that have been added, deleted, or modified in the layer. It will not fire if there have not been any changes.

Types of trigger change

Triggers allow data to be added, deleted or modified as part of the same operation that caused the trigger event.

Triggers use the execution task framework to write further changes to the data. This framework is common to custom panels and smart templates. Please refer to the execution tasks page and subpages to better understand how to update data.

Trigger behaviour

Triggers will fire after topology and attributes rules have been applied to the data. Any subsequent data changes made by triggers will not be run through the topology or attribute rules.

All row level triggers will wire, before table level triggers.