How to veto a transition in jira through sdk

Question

I want to prevent few transitions based on ceratin conditions through jira sdk.

for Eg. i dont want a subtask to be transitoned to "In Progress" if the subtask above it is not "DONE"

Nic Brough -Adaptavist- · Answer

The code in a condition returns a simple true or false result.  If it is true, the user can use the transition.  If it is false, they will not be offered the transition and can't perform it.

akshay gupta · Answer

i will write the code to validate my condition,

but i dont know how I  will be able to prevent the issue transition

Nic Brough -Adaptavist- · Answer

You will need to find or write some code to do that.  Something that provides a condition.