BaseController.java

package controllers;

import models.Answer;
import models.Comment;
import models.Entry;
import models.Question;
import models.User;
import play.mvc.Before;
import play.mvc.Controller;
import play.mvc.Http;

/**
 * Some basic methods that should be available to all controllers.
 */
public abstract class BaseController extends Controller {

	/**
	 * Makes the connected user available to all views as 'user'.
	 */
	@Before
	static void setConnectedUser() {
		if (Security.isConnected()) {
			User user = Database.users().get(Security.connected());
			renderArgs.put("user", user);
		}
	}

	/**
	 * Redirects to the calling page.
	 * 
	 * @return true, if a redirect header was found; false, if the caller should
	 *         call an explicit Controller action instead.
	 */
	protected static boolean redirectToCallingPage() {
		Http.Header referer = request.headers.get("referer");
		if (referer == null)
			return false;
		redirect(referer.value());
		return true;
	}

	/**
	 * Gets an answer to a question or <code>null</code> if it doesn't exist.
	 * 
	 * @param questionId
	 *            the question's id
	 * @param answerId
	 *            the answer's id
	 * @return the answer, if it exists
	 */
	protected static Answer getAnswer(int questionId, int answerId) {
		Question question = Database.questions().get(questionId);
		if (question == null)
			return null;
		return question.getAnswer(answerId);
	}

	/**
	 * Gets a comment to a question or an answer, or <code>null</code> if it
	 * doesn't exist.
	 * 
	 * @param questionId
	 *            the question's id
	 * @param answerId
	 *            the answer's id or an invalid ID for getting a question's
	 *            comment
	 * @param commentId
	 *            the comment's id
	 * @return the answer, if it exists
	 */
	protected static Comment getComment(int questionId, int answerId,
			int commentId) {
		Question question = Database.questions().get(questionId);
		if (question == null)
			return null;
		Answer answer = question.getAnswer(answerId);
		if (answer == null)
			return question.getComment(commentId);
		return answer.getComment(commentId);
	}

	/**
	 * Checks whether a {@link User} can edit a profile.
	 * 
	 * @param showUser
	 *            the {@link User} who is the owner of the profile.
	 * @return
	 */
	protected static boolean userCanEditProfile(User showUser) {
		User user = Session.user();
		if (user == null)
			return false;
		return user == showUser && !showUser.isBlocked() || user.isModerator();
	}

	/**
	 * Marks a given entry as possibly spam (ordinary user) or as definitively
	 * spam (moderators). In the first case, a notification is sent to all
	 * moderators in their spam report; otherwise the entry is deleted and the
	 * entry's owner is blocked as a spammer.
	 * 
	 * @param spam
	 *            the Entry that might be spam
	 */
	protected static void markSpam(Entry spam) {
		User user = Session.user();
		if (spam != null && user != null) {
			if (!user.isModerator()) {
				spam.markSpam(Database.users().getModeratorMailbox());
				flash.success("spam.thx.user");
			} else {
				spam.confirmSpam();
				flash.success("spam.thx.mod");
			}
		}
	}
}