socialforge/app/helpers/courses_helper.rb

## This helper be included in applicationHelper
module CoursesHelper
=begin
	1. define TeacherRoles, StudentRoles
	2. define count function
	3. define search by roles
	4. define search member function
=end
	TeacherRoles = [3, 4, 7, 9]
	StudentRoles = [5, 10]

	## return people count

	# 返回教师数量，即roles表中定义的Manager
	def teacherCount project
		# searchCountByRoles project, TeacherRoles
		# or
		searchTeacherAndAssistant(project).count
	end
	# 返回学生数量，即roles表中定义的Reporter
	def studentCount project
		# searchCountByRoles project,StudentRoles
		# or
		searchStudent(project).count
	end

	# =====================================================================================
	# return people list
	def searchTeacherAndAssistant project
		searchPeopleByRoles(project, TeacherRoles)
	end

	def searchStudent project
		searchPeopleByRoles(project, StudentRoles)
	end
	# =====================================================================================
	
	def searchCountByRoles project, roles_id
		people = searchPeopleByRoles project, roles_id
		people.count
	end

	def searchPeopleByRoles project, roles_id
		people = []
		begin
			people = project.members.joins(:member_roles).where("member_roles.role_id IN (:role_id)", {:role_id => roles_id})
		rescue Exception => e
			logger.error "[CoursesHelper] ===> #{e}"
		end
		people
	end

	#useless
	def searchPeopleByRole project, role_id
		people = []
		begin
			people = project.members.joins(:member_roles).where("member_roles.role_id = :role_id", {:role_id => role_id })
		rescue Exception => e
			logger.error "[CoursesHelper] ===> #{e}"
		end
		people
	end
end