Page History

package x.y.z.authentication;

import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.wicket.Page;
import org.apache.wicket.RequestCycle;
import org.apache.wicket.ajax.AbstractDefaultAjaxBehavior;
import org.apache.wicket.ajax.AjaxRequestTarget;
import org.apache.wicket.markup.html.JavascriptPackageResource;
import org.apache.wicket.markup.html.basic.Label;
import org.apache.wicket.markup.html.panel.Panel;
import org.apache.wicket.model.AbstractReadOnlyModel;
import org.apache.wicket.protocol.http.WebRequestCycle;
import x.y.z.AuthWebSession;

/**
 * Minimalistic Panel for Facebook-Login-Management
 * 
 *  - as a single Button you can put into every Page
 *  - as a basis for a full-blown Login-Page
 * 
 * @author Markus Lachinger <markus.lachinger äT gmail com>
 * 
 */
public class FacebookSignInPanel extends Panel {
	/**
	 * default SID
	 */
	private static final long serialVersionUID = 1L;
	private static final Log log = LogFactory.getLog(FacebookSignInPanel.class);

	protected String apiId = "yourAPIkey";
	protected String secret = "yourSecret";

	/** Wrapper to super() **/
	public FacebookSignInPanel(String id) {
		super(id);
                createPanel();
	}

	/**
	 * This method will load the Facebook-API and manage login-states
	 */
	public void createPanel() {
		// Add and initialize Facebook-API
		add(JavascriptPackageResource
				.getHeaderContribution("http://connect.facebook.net/en_US/all.js"));
		StringBuffer sb = new StringBuffer();
		sb.append("FB.init({");
		sb.append("    appId: '"+ apiId +"',");
		sb.append("    status: true,");
		sb.append("    cookie: true,");
		sb.append("    xfbml: true");
		sb.append("});");
		
		// set Event-Handler for Login and Logout
		sb.append("FB.Event.subscribe('auth.login', function(respond){callWicketLogin(respond)});");
		sb.append("FB.Event.subscribe('auth.logout', function(respond){callWicketLogout(respond)});");

		// If the User is already logged in into Facebook, send this to Session
		if(!((AuthWebSession) getSession()).isSignedIn()) {
			 sb.append("FB.getLoginStatus(function(response){");
			 sb.append("if (response.session) {");
			 sb.append("  FB.api('/me', function(response){");
			 sb.append("	if(response.session) {");
			 sb.append("    	callWicketLogin(response);");
			 sb.append("	} else {");
			 sb.append("		FB.login(function(res) {");
			 sb.append("			callWicketLogin(res); }");
			 sb.append("		)");	
			 sb.append("		}");
			 sb.append("	})");
			 sb.append("  };");
//			 sb.append("  else {");
//			 sb.append("    alert(\"not logged in\");");
//			 sb.append("   }");
			 sb.append("  });");
		}

		Label FBapi = new Label("FBapi", sb.toString());
		FBapi.setEscapeModelStrings(false);
		add(FBapi);

		/**
		 * Javascript-Wicket-Bridge that gets called after a successful login
		 * contains Facebook-UserID, Facebook-SessionId for i.e. JSON and
		 * AccessToken (OAuth2)
		 */
		final AbstractDefaultAjaxBehavior loginBehavior = new AbstractDefaultAjaxBehavior() {
			protected void respond(final AjaxRequestTarget target) {
				handleLoginEventCallback(target.getPage());
			}
		};
		add(loginBehavior);

		/**
		 * Javascript-Wicket-Bridge that gets called after a logout occurred
		 */
		final AbstractDefaultAjaxBehavior logoutBehavior = new AbstractDefaultAjaxBehavior() {
			protected void respond(final AjaxRequestTarget target) {
				//log out the user but keep the session
				((AuthWebSession) getSession()).signOut();
			}
		};
		add(logoutBehavior);

		Label loginCallback = new Label("loginCallback", new AbstractReadOnlyModel<String>() {
			@Override
			public String getObject() {
				CharSequence url = loginBehavior.getCallbackUrl();
				StringBuffer sb = new StringBuffer();
				sb.append("function callWicketLogin(response) { \n");
				sb.append("		if (response.session) {\n");
				//optional: check permissions here if all necessary are granted!
				//example:  (2010/6/1 @ http://developers.facebook.com/docs/reference/javascript/FB.login)
//					    if (response.perms) {
//					      // user is logged in and granted some permissions.
//					      // perms is a comma separated list of granted permissions
//					    } else {
//					      // user is logged in, but did not grant any permissions
//					    }
				sb.append("     	var wcall = wicketAjaxGet('");
				sb.append(url);
				sb.append("&fbid='+ response.session.uid +'");
				//SessionId in case you want to use the old API
				sb.append("&fbsessid='+ response.session.session_key +'");
				//AccessToken for new OAuth2-based requests
				sb.append("&fbaccesstoken='+ response.session.access_token");
				sb.append(", function() { }, function() { });\n");
				sb.append("    	} else {\n");
				sb.append("			alert(\"Sorry, there was some kind of error in the Facebook-login. Please try again.\");");
				sb.append("		}\n");
				sb.append("}\n");
				return sb.toString();
			}
		});
		loginCallback.setEscapeModelStrings(false);
		loginCallback.setOutputMarkupId(true);
		add(loginCallback);

		Label logoutCallback = new Label("logoutCallback", new AbstractReadOnlyModel<String>() {
			@Override
			public String getObject() {
				CharSequence url = logoutBehavior.getCallbackUrl();
				StringBuffer sb = new StringBuffer();
				sb.append("function callWicketLogout(response) { \n");
				sb.append("alert(\"You have been logged out from facebook. We will log you out too - see FAQ\");");
				sb.append("     var wcall = wicketAjaxGet('");
				sb.append(url);
				sb.append("', function() { }, function() { });");
				sb.append("    }");
				return sb.toString();
			}
		});
		logoutCallback.setEscapeModelStrings(false);
		logoutCallback.setOutputMarkupId(true);
		add(logoutCallback);

	}

	public void handleLoginEventCallback(Page p) {
		Map<String, String[]> map = ((WebRequestCycle) RequestCycle.get()).getRequest().getParameterMap();
		
		String uid = map.get("fbid")[0];
		String accessToken = map.get("fbaccesstoken")[0];
		
		if(!((AuthWebSession) getSession()).signInFacebook(accessToken, uid)) {
			error("Sorry, something went wrong with the Login - please try again.");
		}
	}

}