Checking for Superseded Add-ons

The Factory.AddOn.fetchSupersedingInstance method allows an application to check for a superseding add-on based on the add-on ID that is passed to the method. If a superseding add-on does not exist in the domain, then the method returns the add-on that is specified in the call. If the superseding add-on exists, then the method returns the superseding add-on (which has a different ID than the one specified in the method call).

The ObjectStore.isAddOnInstalled method tells an application if a specified add-on is installed in the object store. This method takes the ID of an add-on. To determine whether an updated version of an add-on is installed, an application passes the ID of the superseded add-on to the method. The method returns false in cases where an add-on has not been installed to the object store.

The following Java™ and C# examples use the ObjectStore.isAddOnInstalled method. If the specified add-on has not been installed to the object store, the code installs it.

Java Example

void installOn(Domain domain, AddOn addOn)
{
        if ( objectStore.isAddOnInstalled(addOn.get_Id()) == false )
        {              
            System.out.println("+++ Installing " + 
               addOn.get_DisplayName() + " into object store " + 
               objectStore.get_DisplayName() + " ...");
            objectStore.installAddOn(addOn);
            objectStore.save(RefreshMode.REFRESH);
        }
        else
        {
            System.out.println("--- " + addOn.get_DisplayName() + " already installed in object store " + 
               objectStore.get_DisplayName() + ".");
        }
}

C# Example

void installOn(IDomain domain, IAddOn addOn)
{
        if ( objectStore.IsAddOnInstalled(addOn.Id) == False )
        {              
            System.Console.WriteLine("+++ Installing " + 
               addOn.DisplayName + " into object store " + 
               objectStore.DisplayName + " ...");
            objectStore.InstallAddOn(addOn);
            objectStore.Save(RefreshMode.REFRESH);
        }
        else
        {
            System.Console.WriteLine("--- " + addOn.DisplayName + " already installed in object store " + 
               objectStore.DisplayName + ".");
        }
}