Life of Transient repository varibles in ATG

Question

How long do transient repository variables are alive in memory? Are they linked to the session?
I read that they are not related to Cache, so any cache invalidation events would not effect their life cycle.
Thanks
Edited by: Soltan on Jun 27, 2012 10:09 AM - edited to transient repository variables

Answer 1

Soltan wrote:
Thanks for the answer Nitin. Per your answer, do you mean that Transient properties are available as long as the repository is up? I may be interpreting it wrong.
If I create a transient variable say in the profile repository item, wouldn't it be lost once the user's profile object is no longer in scope (session timeout or user logs out) ? The issue I am seeing is that my transient variables are being lost if there is some sort of error (not necessarily related to the repository). Is there a way to know how long these variables are held in memory and when they are discarded.
The transient property would be available as a state of the RepositoryItem object. On referring to a different RepositoryItem, definitely the transient's property's value would be lost or changed (depending on if you made the transient property as a user defined property to get its value from a RepositoryPropertyDescriptor). So if you add a transient property in the profile, it be would lost or changed once the underlying RepositoryItem changes when session times out or user logs out. I have not tried this but you can go through with the documentation to see if you can possibly use a PropertiesChangedListener to detect when the property value changes.
Soltan wrote:
I have a few in the order repository on the commerceItem, that hold information about manual discount values. If there is an error during checkout (payment >or such), I still have the order, commerce items, promotions etc but these manual discount values (which are transient properties) are disappearing. So the next >time reprice happens I am missing these discount values.I believe somewhere you must be setting the discount related values into those transient properties in the order so can't you set them again on repricing after an error?
As an alternative, see if you can make your transient property for manual discount as a user defined property by adding property-type attribute to your repository definition XML. Something like as:
<property name="manualDiscount" property-type="mypackage.ManualDiscountPropertyDescriptor">
  <!-- if required you can pass additional attributes and values to your RepositoryPropertyDescriptor -->
</property>Then implement ManualDiscountPropertyDescriptor to hold your discount information and required logic as there will be one instance of ManualDiscountPropertyDescriptor class which would be used for manualDiscount property irrespective of user session as long as repository is up.
public class ManualDiscountPropertyDescriptor extends RepositoryPropertyDescriptor {
public Object getPropertyValue(RepositoryItemImpl item, Object value) {
// here item parameter is the order RepositoryItem on which you are calling the property getter
// return value based on your logic using data from order and discount info
}For more details, you can refer to user defined property type section in ATG Repository guide which has an example also.