execute method

@override JinjaValue execute(Context ctx)

Executes the statement within the given ctx and returns the result as a JinjaValue.

Implementation

@override
JinjaValue execute(Context ctx) {
  final val = operand.execute(ctx);

  // Resolve filter function
  String filterName;
  List<JinjaValue> args = [val]; // Filter receives value as first arg
  Map<String, JinjaValue> kwargs = {};

  if (filter is Identifier) {
    filterName = (filter as Identifier).name;
  } else if (filter is CallExpression) {
    final call = filter as CallExpression;
    if (call.callee is! Identifier) {
      throw Exception('Filter must be identifier');
    }
    filterName = (call.callee as Identifier).name;
    // Evaluate args
    for (final arg in call.args) {
      if (arg is KeywordArgumentExpression) {
        kwargs[(arg.key as Identifier).name] = arg.val.execute(ctx);
      } else if (arg is Expression) {
        args.add(arg.execute(ctx));
      }
    }
  } else {
    throw Exception('Invalid filter expression');
  }

  if (globalFilters.containsKey(filterName)) {
    final res = globalFilters[filterName]!(args, kwargs);
    return deriveRendered(res, [...args, ...kwargs.values]);
  }
  throw Exception('Unknown filter: $filterName');
}