/// <summary>
/// Check if the list of pre-requisites is different in any way
/// If so, then returns true
/// </summary>
/// <returns></returns>
public bool IsPreReqListDifferent()
{
try
{
using (var context = new SchoolU_DBEntities())
{
// Gets the course object based on the selected Department Name
Course currentlySelectedCourse = context.Courses.Where(i => i.CourseName == CourseName).Single();
// Variable to keep track of difference in pre-req list
bool isDifferent = true;
IList <int> preReqIds = (from c in context.Courses
join pr in context.PreRequisites on c.CourseId equals pr.CourseId
where c.CourseId == currentlySelectedCourse.CourseId
select pr.PrereqId).ToList();
if (preReqIds.Any())
{
// Gets the course name based on the Pre-req Id
IList <Course> course_Name = context.Courses.Where(i => preReqIds.Contains(i.CourseId)).ToList();
if (SelectedCourseCollection.Count() == preReqIds.Count())
{
foreach (var item in course_Name)
{
// IsDifferent is set to false when the list hasn't changed at all
if (SelectedCourseCollection.Where(i => i.CourseId == item.CourseId).Any())
{
isDifferent = false;
}
// IsDifferent is set to true when the list is different in one or more ways
else
{
return(true);
}
}
}
}
return(isDifferent);
}
}
catch (Exception ex)
{
//MessageBox.Show(ex.Message);
return(false);
}
}
/// <summary>
/// Gets a list of course Ids based on the pre-req names
/// currently in the pre-reqs list (SelectedCourseCollection)
/// </summary>
/// <returns></returns>
public IList <int> GetPreReqIds()
{
IList <int> preReqIds = new List <int>();
try
{
using (var context = new SchoolU_DBEntities())
{
if (SelectedCourseCollection.Any())
{
// Gets all the pre-req courses names
IList <string> pre_reqNames = SelectedCourseCollection.Where(i => i.CourseName != string.Empty).Select(i => i.CourseName).ToList();
// Gets all the course ids off of the courses names added to the pre-reqs list // pre-req = course ids
return(preReqIds = context.Courses.Where(i => pre_reqNames.Contains(i.CourseName)).Select(i => i.CourseId).ToList());
}
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
return(null);
}
return(null);
}
/// <summary>
/// Checks if the course in edit is added
/// as it's own pre-requisite
/// </summary>
/// <returns></returns>
public bool IsCourseItsOwnPreRequisite()
{
return(GetPreReqIds().Contains(SelectedCourseCollection.Where(i => i.CourseName == CourseName).Select(i => i.CourseId).SingleOrDefault()));
}