/// <summary>
/// Adds the course to the list of courses.
/// If an entry for the given CourseID does not exist
/// in the course template list, an object not found exception is thrown.
/// </summary>
/// <param name="course"></param>
/// <returns></returns>
public CourseDetailsDTO AddCourse(AddCourseViewModel course)
{
// 1. Validation
var courseTemplate = _db.CourseTemplates.SingleOrDefault(x => x.CourseID == course.CourseID);
if (courseTemplate == null)
{
throw new CourseNotFoundException();
}
// 2. Create the database object
var courseEntity = new Course
{
CourseID = course.CourseID,
StartDate = course.StartDate,
EndDate = course.EndDate,
Semester = course.Semester
};
_db.Courses.Add(courseEntity);
_db.SaveChanges();
// 3. Create the return object
var createdCourseEntity = _db.Courses.SingleOrDefault(x => x.CourseID == course.CourseID && x.Semester == course.Semester);
CourseDetailsDTO courseDTO = new CourseDetailsDTO
{
ID = createdCourseEntity.ID,
CourseID = course.CourseID,
StartDate = course.StartDate,
EndDate = course.EndDate,
Name = courseTemplate.Name,
Students = null
};
return courseDTO;
}
/// <summary>
/// Returns a single course with the specified ID
/// If no course is found then a course not found exception is thrown
/// </summary>
/// <param name="courseModel"></param>
/// <returns></returns>
public CourseDetailsDTO GetCourseByID(int ID)
{
var course = _db.Courses.SingleOrDefault(x => x.ID == ID);
// 1. Validation
if(course == null)
{
throw new CourseNotFoundException();
}
var courseTemplate = _db.CourseTemplates.SingleOrDefault(x => x.CourseID == course.CourseID);
if(courseTemplate == null)
{
throw new ApplicationException("Something went horribly wrong");
}
// Populating the list of students enrolled in the course
var students = (from c in _db.CourseRegistrations
from p in _db.Persons
where c.CourseID == course.ID
where c.StudentID == p.ID
select new StudentDTO
{
ID = c.StudentID,
Name = p.Name,
SSN = p.SSN
}).ToList();
var returnValue = new CourseDetailsDTO
{
ID = course.ID,
CourseID = course.CourseID,
Name = courseTemplate.Name,
StartDate = course.StartDate,
EndDate = course.EndDate,
Students = students
};
return returnValue;
}
