How can we keep only recently configured leaf or replace existing with new?

YANG
1

Assume that I have configured all leaf.

container test{
list ipv4-list {
			key "ipv4addr";
			leaf ipv4addr {  type inet:ipv4-prefix; }
			leaf lid { type yang:counter64 ; }
			leaf glid { type yang:counter64; }
			leaf lsn-lid { type yang:counter64 ; }
			leaf age { type yang:counter64; }
		} 
		}

Next time when I configure
case 1:
ipv4addr lid
then
only ipv4addr and lid and age should be set and rest other should be reset.

case 2:
ipv4addr lid glid
then
only ipv4addr, lid, glid and age should be set and rest other should be reset.

i.e. at any point, only recent configuration should be present (for first 4 leaf).
Can we put such constrain?

2

You could use hooks (UG - chapter “Hooks”) to modify running transaction depending on changes explicitly done by user,. Though, please note that this type of auto-configuration of YANG elements may cause issues with higher device management layers, if applicable in your scenarios/use-cases.

It adds sort of extra business-logic that may need to be addressed (user has to realize this when working with config, higher layer network management software can hit out-of-sync configuration state, etc.)