How to veto a transition in jira through sdk

[akshay gupta]

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-]

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

[akshay gupta]

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-]

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.