Pre-Saved Callouts are not a validation rule; they are used to perform a pre-save calculation on the record before the record is created or updated. For example, a Pre-Save Callout could conditionally define a default value for an attribute or calculate a primary key based on other attribute values. If it is a compiled class, it may define a primary key using data in an external table or repository, for instance, selecting a number from a pool of available numbers, then removing the number from the pool.
Pre-Save Callouts include:
VTLUpdatePreSaveCallout – updates the record using the VTL script defined in the callout properties.
AttributeVTLCaclulatePreSaveCallout
PriceCopyPreSaveCallout
AttributesSearchAndUpdatePrice
GroovyPreSave – executes a Java-based Groovy script defined in the callout properties.
NodeJSPreSave
<custom> - any Java class that follows the Pre-Save Callout interface can be implemented to perform a pre-save operation.