How to refine a leaf's range in YANG model?

Question

I have a grouping like -

  grouping threshold-value-grouping {
    container threshold-value {
      description "Threshold value";
      leaf upper-limit-val {
        description
          "Upper limit";
        type uint32 {
          range "1..60000";
        }
      }
      leaf lower-limit-val {
        description
          "Lower limit";
        type uint32 {
          range "1..60000";
        }
      }
    }
  }

And i want to reuse this grouping at multiple places. But when used at different places, the range of the leaves vary.

So i am wondering how can I use the refine statement to achieve? Or is there any better way to address this issue?

Answer 1

Section 7.13.2 of RFC 7950 explicitly specifies all possible refinements and range is not one of them. Neither is type which can also be seen in the ABNF grammar (section 14):

refine-stmt         = refine-keyword sep refine-arg-str optsep
                       "{" stmtsep
                           ;; these stmts can appear in any order
                           *if-feature-stmt
                           *must-stmt
                           [presence-stmt]
                           *default-stmt
                           [config-stmt]
                           [mandatory-stmt]
                           [min-elements-stmt]
                           [max-elements-stmt]
                           [description-stmt]
                           [reference-stmt]
                         "}" stmtsep

But what you can do is to add a must constraint here, something like

uses threshold-value-grouping {
    refine threshold-value/upper-limit-val {
        must '(. >= 10 and . <= 100)' {
            error-message "Here you can only use values between 10 and 100";
        }
    }
}