public async Task <IActionResult> GetAllStudents(
[FromQuery] string firstName = "",
string lastName = "",
string middleName = "",
StudentSex?sex = null,
string nickname = "",
string groupName = "",
int skip = 0,
int take = 0)
{
var filter = new StudentListFilter
{
GroupName = groupName,
FirstName = firstName,
LastName = lastName,
MiddleName = middleName,
Nickname = nickname,
Sex = sex,
Skip = skip,
Take = take
};
var result = await _studentService.GetStudents(filter);
return(new JsonResult(result));
}
/// <summary>
/// Получение списка студентов с возможностью пагинации и фильтрации
/// </summary>
/// <param name="filter">Фильтры поиска</param>
/// <returns>Список студентов и количество доступных студентов с данными фильтрами</returns>
public async Task <StudentList> GetStudents(StudentListFilter filter)
{
var result = new StudentList();
var filteredList = FilterStudents(filter);
result.Count = filteredList.Count();
result.Students = await filteredList
.Paging(filter.Take, filter.Skip)
.Select(s => (StudentListItem)s)
.ToListAsync();
return(result);
}
/// <summary>
/// Начальная фильтрация студентов
/// </summary>
/// <param name="filter">Фильтры</param>
/// <returns>Отфильтрованный список студентов</returns>
private IQueryable <Student> FilterStudents(StudentListFilter filter)
{
IQueryable <Student> query = _context.Students
// В EF Core LazyLoading организована через прокси, так что при обращении извне нужен Include
.Include(s => s.Groups)
.ThenInclude(sg => sg.Group);
foreach (var condition in filter.GetConditionExpressions())
{
query = query.Where(condition);
}
return(query);
}
/// <summary>
/// Получение списка ExpressionTree, которые можно затем кидать в LINQ, на основе фильтров
/// </summary>
/// <param name="filter">Фильтры</param>
/// <returns>Список ExpressionTree</returns>
public static IEnumerable <Expression <Func <Student, bool> > > GetConditionExpressions(this StudentListFilter filter)
{
var allConditions = new List <(bool Condition, Expression <Func <Student, bool> > Expression)>
{
(!string.IsNullOrWhiteSpace(filter.FirstName), s => s.FirstName.Contains(filter.FirstName)),
(!string.IsNullOrWhiteSpace(filter.LastName), s => s.LastName.Contains(filter.LastName)),
(!string.IsNullOrWhiteSpace(filter.MiddleName), s => s.MiddleName.Contains(filter.MiddleName)),
(!string.IsNullOrWhiteSpace(filter.Nickname), s => s.Nickname.Contains(filter.Nickname)),
(filter.Sex != null, s => s.Sex == filter.Sex),
(!string.IsNullOrWhiteSpace(filter.GroupName), s => s.Groups.Any(g => g.Group.Name.Contains(filter.GroupName))),
};
foreach (var condition in allConditions.Where(c => c.Condition))
{
yield return(condition.Expression);
}
}
