How to add new custom field to Transform and Compose section of Event Rule / How to popuate custom Alert field.

• By Default OOTB, we have some selective fields that are displayed under the Transpose and Compose section of Event Rule. 
• The Business Requirement here is to add some new fields to this section as below.

• Currently, it displays only OOTB fields.

Solution 1

• In order to display any custom field to this view, below steps needs to be followed:
  
  
  • Open "sys_db_object" table and locate "em_alert" table record. [Name Is em_alert]
  • Under Columns Tab > Click New
  • Enter the Field details that you would like to add and save the record. For example

Table: Alert [em_alert]
Type: String
Column label: NR Custom
Column name: nr_custom
Max length: 240

• • This will create a new custom field on the Alert table.
    
• Now navigate to the Event rule and see if the new field is visible or not.

Solution 2

• Apart from the above approach, there is another way of populating a custom alert field.
  
  "Alert fields are automatically populated from fields that have the same name in the event. This behavior holds true for Additional information event fields and for Additional information fields that Event Rule adds. Thus to populate a custom alert field with the value in Additional information fields of alert, use the custom field name in the Additional information field of the event." Please refer to Custom Alert Fields for more details. 
  
  
• Which means, if you are passing the custom field in the event payload and it will automatically get populated in the alert. Below is a sample Additional Information payload.
  {'nr_custom':'custom value','hostname':'','networkNodeId':'1463','swEventId':'36479354','icon':'Start','netObjectId':'1463','NetObjectType':'N','eventType':'5001'}

• The important thing to notice here is, a new custom added field can be displayed under the "Transform and Compose Alert Output" section along with the selected/default OOTB fields. Please note, some of the OOTB fields on em_alert table are not displayed here, this is by design.
  
• Apart from the above OOTB fields selected, the behavior of short_description field can be controlled using "evt_mgmt.override_alert_short_description". property.
• The short description field of an alert is automatically written using the type, node, and description of the alert. To prevent the short description field from being over-written, the evt_mgmt.override_alert_short_description property value can be set to false.

Additional document: 
View alert information