781 void QQmlContextData::refreshExpressions()
782 {  
783     bool isGlobal = (parent == nullptr);
784    
785     // For efficiency, we try and minimize the number of guards we have to create
786     if (expressions_to_run(this, isGlobal) && childContexts) {
787         QQmlGuardedContextData guard(this);
788    
789         childContexts->refreshExpressionsRecursive(isGlobal); 
790    
791         if (!guard.isNull() && expressions_to_run(this, isGlobal))
792             refreshExpressionsRecursive(expressions);
793    
794     } else if (expressions_to_run(this, isGlobal)) {
795 
796         refreshExpressionsRecursive(expressions);
797 
798     } else if (childContexts) {
799 
800         childContexts->refreshExpressionsRecursive(isGlobal);
801 
802     }
803 }