Using Session Preferences

To store and share settings within the client browser, use session preferences.

Pagelets can use preferences to communicate with each other, but accessing preferences usually requires a round trip to the portal database. Session preferences provide a way to store and share settings in the user's session within the client browser.

The Master-Detail design pattern illustrates the most basic usage of session preferences. This design pattern splits control and display between two portlets. For example, the "master" portlet could summarize data in list form, and the "detail" portlet could display details on each data item in response to user selection. In the example below, the master portlet displays a form that allows you to enter a color code in a text box.

When the user enters a color code in the text box, the color in the detail portlet changes.

For each onkeyup event that occurs in the "Enter color" text box in the master portlet, the following steps are executed:

The master portlet sets the session preference using the current value of the text box.
The master portlet calls an update method on the detail portlet.
The detail portlet retrieves the session preference to get the color value.
The detail portlet redraws its color swatch area to reflect the new color value.

Pagelets can manipulate session preferences using the ALI Scripting Framework or the IDK. Sample code for both options is provided below.

Note: Shared session preferences must be specified by name on the Preferences page of the associated Web Service Editor or they will not be sent to the pagelet.

ALI Scripting Framework Methods

This example is oversimplified; the master portlet makes a direct call to a JavaScript method of the detail portlet. Unless the master portlet takes extra measures to ensure that the detail portlet is actually present on the same page, calls from master to detail could generate errors. The ALI Scripting Framework provides an easy way to detach the relationship between portlets and use a common event interface for communication. See Using ALI Scripting Framework Event Notification for more information on inter-portlet communication.

Master Portlet

<div style="padding:10px;" align="center">
<p><b>Enter color:</b> &nbsp;
<input type="text" style="font-size:22px;font-weight:bold;text-align:center;" id="master_prefName"
value="#FFFFFF" size="8" onkeyup="master_setPrefs(this.value)"></p><br>
</div>

<script type="text/javascript">
function master_setPrefs(val)
{
var prefName = 'masterColor';
var prefValue = val;
PTPortlet.setSessionPref(prefName,prefValue);

master_debug('<b>Master Portlet</b> called PTPortlet.setSessionPref(\'masterColor\',\'' + prefValue + '\').');

if (window.detail_update)
  {
  master_debug('<b>Master Portlet</b> calling detail_update().');
  detail_update();
  }
else
  {
  master_debug('Could not locate portlet <b>Detail Portlet</b> on page.');
  }
}
function master_debug(str)
{
if (window.PTDebugUtil) 
  { 
  PTDebugUtil.debug(str); 
  }
}
</script>

Detail Portlet

<div style="padding:10px;" align="center">
<p><b>Color swatch</b> &nbsp;
<div style="width:100px;height:100px;border:2px solid black;padding:2px;"id="detail-swatch"></div>
<script>
function detail_update()
{
var color = PTPortlet.getSessionPref('masterColor');
detail_debug('<b>Detail Portlet</b> received value="' + color + '" for PTPortlet.getSessionPref(\'masterColor\')');

var swatch = document.getElementById('detail-swatch');
if (swatch)
  {
  swatch.innerHTML = '<div style="background-color:' + color + ';width:100%;height:100%;"></div>';
  }
else
  {
  detail_debug('<b>Detail Portlet</b> cannot find \'detail-swatch\' DIV element.');
  }
}

function detail_debug(str)
{
if (window.PTDebugUtil) 
  { 
  PTDebugUtil.debug(str); 
  }
}
</script>

IDK Methods

In most cases, reading session preferences via the ALI Scripting Framework is inefficient and insecure. Always use the IDK to read session preferences, as shown in the example code below.

Java

<%@ page language="java" import="com.plumtree.remote.portlet.*,java.util.Date" %>

IPortletContext portletContext = PortletContextFactory.createPortletContext(request,response); 
IPortletResponse portletResponse = portletContext.getResponse(); 
IPortletUser portletUser = portletContext.getUser();
IPortletRequest portletRequest = portletContext.getRequest();

masterColor = portletRequest.getSettingValue(SettingType.Session, "masterColor");

.NET

...
Dim portletContext As IPortletContext
portletContext = PortletContextFactory.CreatePortletContext(Request, Response)

Dim portletRequest As IPortletRequest
portletRequest = PortletContext.GetRequest

Dim portletUser As IPortletUser
portletUser = PortletContext.GetUser

Dim portletResponse As IPortletResponse
portletResponse = PortletContext.GetResponse

Dim masterColor As String
masterColor = portletRequest.GetSettingValue(SettingType.Session "masterColor")
...

Parent topic: About Cross-Platform Pagelet Development

Parent topic: About ALI Portlet Settings

AquaLogic User Interaction Development Guide

Using Session Preferences