Conditional

A conditional expression that selects between two values based on a prop’s state. Introduced in schema 0.13.0.

interface Conditional {
  if: {
    condition: ConditionExpression;
    then: string | boolean | number | null;
    else: string | boolean | number | null;
  };
}

Properties

Property	Type	Required	Description
if.condition	ConditionExpression	Yes	The test to evaluate
if.then	string | boolean | number | null	Yes	Value when condition is true
if.else	string | boolean | number | null	Yes	Value when condition is false

ConditionExpression

Property	Type	Required	Description
operation	string	Yes	Operation to perform
args.value	PropBinding	Yes	The prop to test
args.compareTo	string | number | boolean | null	No	Comparison value (omitted for unary operations)

Operations

Operation	Arity	Description
isNull	Unary	Prop value is null
isNotNull	Unary	Prop value is not null
equals	Binary	Prop value equals compareTo
notEquals	Binary	Prop value does not equal compareTo

Example

Show or hide based on whether a slot prop has content:

if:
  condition:
    operation: isNull
    args:
      value:
        $binding: "#/props/icon"
  then: false
  else: true

Further Reading

• ADR 018 — Conditional Visible Binding — introduces the Conditional type for declarative visibility derived from nullable props