Requirement - When user enters a value in a field(Example__c) then it needs to be validated against an external object and only if the value matches then only we save the changes.
Tried so far - Initially I was using an apex trigger but while developing it came across the fact that Apex Trigger cannot refer an external object, but we can use lightning flow instead.
Problem - I came across this help document: https://help.salesforce.com/s/articleView?id=release-notes.rn_automate_flow_builder_asynchronous_path.htm&release=234&type=5
- Since my update is happening for the same record, I should go for before save option but in document they mentioned about after save.
- Validating against external table needs to be in asynchronous path whereas my requirement is synchronous if I am not wrong.
Need suggestions that what method or process I should follow to handle these issues.