MissingVariableCallback typedef
MissingVariableCallback =
String? Function(String name, MissingVariableContext context)
Called when rendering encounters a missing variable.
The callback receives the missing variable name and contextual information
about the current render. Returning a string substitutes that value for the
missing variable. Returning null preserves the default strict or lenient
behavior.
Implementation
typedef MissingVariableCallback =
String? Function(String name, MissingVariableContext context);