Function guardedExpression

packages/compiler/src/render3/util.ts:68–83

(guard: string, expr: o.Expression)

}

export function guardedExpression(guard: string, expr: o.Expression): o.Expression {
  const guardExpr = new o.ExternalExpr({name: guard, moduleName: null});
  const guardNotDefined = new o.BinaryOperatorExpr(
    o.BinaryOperator.Identical,
    new o.TypeofExpr(guardExpr),
    o.literal('undefined'),
  );
  const guardUndefinedOrTrue = new o.BinaryOperatorExpr(
    o.BinaryOperator.Or,
    guardNotDefined,
    guardExpr,
    /* type */ undefined,
    /* sourceSpan */ undefined,
  );
  return new o.BinaryOperatorExpr(o.BinaryOperator.And, guardUndefinedOrTrue, expr);
}

export function wrapReference(value: any): R3Reference {
  const wrapped = new o.WrappedNodeExpr(value);