private void ValidateCourses()
{
foreach (var course in Courses)
{
//clear prerequisites before recursively checking for circular reference
PrerequisitesCourseList.Clear();
CheckForPrerequisiteCourse(course);
}
}
private void CheckForPrerequisiteCourse(ICollegeCourse course)
{
if (course.HasPrerequisite)
{
var exists = PrerequisitesCourseList.Exists(c => c == course.Prerequisite);
if (exists)
{
throw new CircularPrerequisiteReferenceException(course);
}
PrerequisitesCourseList.Add(course);
CheckForPrerequisiteCourse(course.Prerequisite);
}
}
