Resolve "Smiley Feedback on TAs"

Another form of rating for TA has been added, as well as the smileys in the student-to-TA feedback UI. FontAwesome was upgraded from 4.7 to 5.10.1 due to lack of icons in the former version.

Minor change: description for the textual feedback is changed too, the "only teachers can see this" is removed.

src/main/java/nl/tudelft/ewi/queue/controller/RequestController.java

@@ -25,6 +25,7 @@ import java.util.stream.Stream;
 import javax.persistence.EntityNotFoundException;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
+import javax.validation.Valid;
 
 import nl.tudelft.ewi.queue.annotation.AuthenticatedUser;
 import nl.tudelft.ewi.queue.model.*;
@@ -33,6 +34,7 @@ import nl.tudelft.ewi.queue.service.RequestService;
 import nl.tudelft.ewi.queue.service.RequestTableService;
 import nl.tudelft.ewi.queue.views.View;
 
+import org.hibernate.validator.constraints.Range;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.data.domain.PageRequest;
 import org.springframework.data.domain.Pageable;
@@ -44,6 +46,7 @@ import org.springframework.security.access.prepost.PreAuthorize;
 import org.springframework.stereotype.Controller;
 import org.springframework.ui.Model;
 import org.springframework.util.MultiValueMap;
+import org.springframework.validation.annotation.Validated;
 import org.springframework.web.bind.annotation.*;
 import org.springframework.web.servlet.mvc.support.RedirectAttributes;
 
@@ -53,6 +56,7 @@ import com.querydsl.core.types.Predicate;
 
 @Controller
 @EnableSpringDataWebSupport
+@Validated
 public class RequestController {
 
 	@Autowired
@@ -333,11 +337,17 @@ public class RequestController {
 	@RequestMapping(value = "/request/{id}/feedback", method = RequestMethod.POST)
 	public String feedback(@AuthenticatedUser User user,
 			@PathVariable("id") Long id,
-			@RequestParam(value = "feedback") String feedback,
+			@RequestParam(value = "feedback", required = false) String feedback,
+			@Valid @Range(min = 1L, max = 5L) @RequestParam(value = "rating", required = false) Integer rating,
 			RedirectAttributes redirectAttributes) {
 		Request request = getRequest(id);
 		assert request.getRequestEntity().getId().equals(user.getId());
-		request.setFeedback(feedback);
+		if (!request.getLeftFeedback()) {
+			request.setFeedback(feedback);
+		}
+		if (!request.getLeftFeedbackRating()) {
+			request.setFeedbackRating(rating);
+		}
 		requestRepository.save(request);
 		redirectAttributes.addFlashAttribute("message", "Feedback successfully saved.");
 		return "redirect:/request/" + id;