Extending Liferay's 6.0 session by AJAX call

Hello,
        In case if you are using portlet which has only AJAX call to serverside you have problem with session expiring. See how it can be avoided in this post.

        For extending session Liferay uses session.js script which attached to each page you are opening. This js includes to session_timeout.jspf:

 
  Liferay.Session.init(
   {
    autoExtend: <%= PropsValues.SESSION_TIMEOUT_AUTO_EXTEND %>,
    timeout: <%= sessionTimeout %>,
    timeoutWarning: <%= sessionTimeoutWarning %>,
    redirectOnExpire: <%= PropsValues.SESSION_TIMEOUT_REDIRECT_ON_EXPIRE %>
   }
  );
 

       session_timeout.jspf includes to bottom.jsp which includes to init.vm, so session object present at every page.
       Source code of it you can find in /portal/portal-web/docroot/html/js/liferay/session.js.

        How it works, each time user accessing page session oject created and initialized with method setCookie, which stores  current time value to cookie:

 setCookie: function(status) {
  var instance = this;

  var currentTime = new Date().getTime();

  var options = {
   secure: A.UA.secure
  };

  A.Cookie.set(instance._cookieKey, status || currentTime, options);
 }

      Method checkState checks curent time with stored to cookie session and expires session:

       checkState: function() {
  var instance = this;

  var currentTime = new Date().getTime();
  var sessionState = instance.getCookie();
  var newWaitTime = instance.sessionTimeoutWarning;
  var timeDiff = 0;

  clearTimeout(instance._stateCheck);

  if (sessionState == 'expired') {
   instance.expire();
  }
  else {
   timeDiff = currentTime - sessionState;

   if (!instance.autoExtend) {
    if ((timeDiff + 100) >= instance.sessionTimeoutWarning) {
      instance.warn();
    }
    else {
     newWaitTime = (instance.sessionTimeoutWarning - timeDiff) + 10000;

     instance._stateCheck = setTimeout(
      function() {
       instance.checkState();
      },
     newWaitTime);
    }
   }
   else {
    instance.extend();
   }
  }
 }

          Session can be extend with method extend(), this method also makes AJAX call to server side in order to extend server session (A.io.request(instance._sessionUrls.extend)):

 extend: function() {
  var instance = this;

  if (instance._countdownTimer) {
   clearInterval(instance._countdownTimer);
  }

  A.io.request(instance._sessionUrls.extend);

  document.title = instance._originalTitle;

  instance._currentTime = instance.sessionTimeoutWarning;

  clearTimeout(instance._sessionExpired);

  if (instance._sessionWarning) {
   clearTimeout(instance._sessionWarning);
  }

  instance._sessionWarning = setTimeout(
   function() {
    if (!instance.autoExtend) {
     instance.warn();
    }
    else {
     instance.extend();
    }
   },
   instance._timeoutDiff
  );

  instance.setCookie();
 }

          So extending session with default config can be done only if user reloads page, to extend session with AJAX calls you sholud do next:
      1) create base.js in ext-plugin and include it javascript.everything.files in portal-ext.properties
 
      2) add to base.js : 

   AUI().use('event', function(A){
    A.on('io:start', function(transactionid, arguments){
     if (Liferay.Session._cookieKey != undefined && Liferay.Session._cookieKey != null) {
      if (arguments != 'sessionExtend') {
       Liferay.Session.extendExternal();
      }
     }
    });
   });

            io:start is global AUI event which occurs each time when AJAX call started, so on this event we can call extendSession method.

      3) override session.js in ext-plugin and add/replace next methods:    

   extend: function() {
    var instance = this;

    if (instance._countdownTimer) {
     clearInterval(instance._countdownTimer);
    }
    
    // added in order to differentiate session extend ajax calls and other ajax call, to avoid infinit loop 
    A.io.request(instance._sessionUrls.extend, {
      arguments: 'sessionExtend'
    });

    document.title = instance._originalTitle;

    instance._currentTime = instance.sessionTimeoutWarning;

    clearTimeout(instance._sessionExpired);

    if (instance._sessionWarning) {
     clearTimeout(instance._sessionWarning);
    }

    instance._sessionWarning = setTimeout(
     function() {
      if (!instance.autoExtend) {
       instance.warn();
      }
      else {
       instance.extend();
      }
     },
     instance._timeoutDiff
    );

    instance.setCookie();
   },
   
   extendExternal: function() {
    var instance = this;
    
    if (instance != undefined) {
     instance.extend();
    }
   },

   setCookie: function(status) {
    var instance = this;

    var currentTime = new Date().getTime();

    var options = {
     secure: A.UA.secure,
     path: "/"
    };

    A.Cookie.set(instance._cookieKey, status || currentTime, options);
   }

  
      That's it, after this changes each ajax call will extend session.

BR,
Paul