WCI: Varpacks and Dynamic Reload

Varpacks stands for Variable Packages…As their names show, varpacks are portal objects that do 2 main things:

• Load values from a file into the portal memory (xml format is preferred since there is already a XMLBaseVarPack class that helps load simple XML files)
• Help access these loaded in memory values from anywhere within the portal application – very likely from your portal “customization” code (i.e. custom activity space, custom view, PEIs, )

The goal here is not to re-explain what Varpacks are, since it is already pretty well explained in the ALUI/WCI developer documentation (4 pages):

http://download.oracle.com/docs/cd/E13174_01/alui/devdoc/docs60/Customizing_the_Portal_UI/Using_Varpacks/plumtreedevdoc_customizing_varpack_intro.htm

The goal here is to explain the following 2 points:

1. Portal does not have always have to be restarted to load the new Varpack values from the XML file.
2. Developed properly, a varpack can load/access “experience definition” specific values, which can be very useful when you portal powers multiple portal sites, each with their own different settings etc…

1 - First, to allow you varpack to be reloaded dynamically without the need to restart the portal, you simply need to specify it in your varpack code… and really, it is as simple as overriding the following method:

public override bool CanReloadVarPackFromUI(){
    return true;
}

If the method returns true, then the varpack can be reloaded from the UI, otherwise, it cannot…and then can be reloaded only at portal startup (hence requiring portal restart if you change a value in your varpack XML file)…

And what is this UI? It is the fairly unknown “MemoryDebug” activity space (see this article from Function1 that explains how to access it: http://www.function1.com/site/2007/06/alui-portal-memory-debug-page.html).

Now, if you did everything correctly with your varpack development and deployment, you should see in the “MemoryDebug” screen your varpack name in the list of loaded varpack, and a “view” button by it…And if you returned “true” on the overridden CanReloadVarPackFromUI method as shown above, then a “Reload” button will also show up. As you imagine, clicking “reload” will launch the process that loads the values from your varpack XML file into portal memory, hence reloading your new Varpack values without having to restart the portal.

2 – Secondly, let’s imagine your single portal environment powers multiple portals, each with their own style, colors, hostname…etc…well it is easy to imagine, really: that’s what we do almost every time, and that’s what portal is for.

But now, let’s imagine that you built these customization that should be loaded only within portal site A, but not within portal site B…In other word, you want to selectively load your customizations based on criteria such as portal hostname or experience definition ID…mmmmm that is not really possible since your customizations (view replacement, PEIs, custom activity space, etc…) are dynamically loaded when the portal starts and activated directly once loaded…

But with the use of a properly developed Varpacks, you could actually achieve the above scenario easily…

What you need to do is to make your Varpack aware of the experience definition you are currently in, and then define in your XML file variable names suffixed with an experience definition ID.

Here is a sample XML file:

<?xml version="1.0" encoding="UTF-8"?>
<MyCustomVarpack>
  <Section1-200>
    <mycustomkey1 value="" />
    <mycustomkey2 value="" />
    <mycustomkey3 value="" />
    <mycustomkey4 value="" />
  </Section1-200>
  <Section2-201>
    <mycustomkey1 value="" />
    <mycustomkey2 value="" />
    <mycustomkey3 value="" />
    <mycustomkey4 value="" />
  </Section2-201>
</MyCustomVarpack>

As you can see, the sections have an ID appended to it…this ID represents the experience definition ID where the values within this section will be applicable….And as you can see, using this name formatting, you can potentially define completely different values for experience definition 201.

Now, how to make your Varpack class aware of the current experience ID you are in…well you simply need to store the experience definition ID in an instance variable of your varpack object…see the code below:

public class MyCustomUIVarPack : XMLBaseVarPack
{
    private static OpenLogger log = OpenLogService.GetLogger("MyCustomUIVarPackLibrary",typeof(MyCustomUIVarPack ));
    
    private int m_ExpId = -1;
    private void SetExperienceId(int expDefId)
    {
        m_ExpId = expDefId;
    }
    ... ...
    ... ...
}

Then, to assign the current experience definition ID to this instance variable, you need to find the experience definition ID you are in using the call: TaskAPIServerSubPortal.GetSubPortalCachedObject(oUserSession)…

And then, simply assign the ID to the variable using the defined setter SetExperienceId(int expDefId)…here is the code:

//getting the varpack instance
MyCustomUIVarPack customVarpack = (MyCustomUIVarPack)vPackMgr.GetVariablePackage(MyCustomUIVarPack.VARPACK_ID);

//getting the experience definition using the user session
IPTSubPortalInfo objSubportalinfo = TaskAPIServerSubPortal.GetSubPortalCachedObject(oUserSession);
If(null != objSubportalinfo)
{
    Log.Debug("Subportal Info Object ID is: {0}",objSubportalinfo.GetObjectID());
    customVarpack.SetExperienceId(objSubportalinfo.GetObjectID());
}

Ok, with that done, your varpack object is now “experience definition aware”…and as such, you can simply override the Varpack GetValueAsString / GetValueAsBoolean / GetValueAsInt methods, appending the experience definition ID to the varpack key you want to get the value from.

I hope this article will give you a couple of new ideas in regards of Varpacks…but really will make you realize (if not already) that the WCI Varpack framework is definitely pretty cool and powerful.

As always, let me know what you think…and let me know if you used varpacks to implement other cool use cases…