Refresh (reload) content after language change

You could set language phrases on bindable variables. Then link the text components to them. Any language change redefines the value of the variables, instantly modifing your labels, textareas, etc..

Example:

// On a data model (you could set the whole class as bindable)
// Define different language labels
[Bindable]
public var labelUsername:String;
[Bindable]
public var labelPassword:String;
// On an action controller
// This action modifies current language
protected function changeLanguage(newLanguage:String):void
{
     switch(newLanguage)
     {
          case 'english':
               langModel.labelUsername = 'Username';
               langModel.labelPassword = 'Password';
               break;
          case 'spanish':
               langModel.labelUsername = 'Nombre de usuario';
               langModel.labelPassword = 'Contraseña';
               break;
     }
}
// On a view, the text component
<s:Label text="{langModel.labelUsername}" />

This way, anytime you call the "changeLanguage()" method, the label will reflect the changes inmediatly.