what is the best method and correct API to create a session scope variable?
I am currently using ADFContext().getCurrent().getSessionScope().get()/put(), but it looks like it has some problems: for some unkown reasons I loose the variable, that is get() returns null when called from a method of a (overridden)ViewRowImpl. Why does this happen?
Thanks you in advance
There are a couple of ways you can set values on a sessions scope but I would have to question if you really need a scope as high as session to accomplish what you want to do. At any rate, you should be able to store the value using the method you described but you could also try setting it using EL by using the setExpressionValue and resolveExpression methods in JSFUtils.java (you can find this in the latest fusion demo application). JSFUtils also has a getFromSession and storeOnSession that you could try.
With all that said I don't think it is good practice to access scope variables from your model layer. You should write your method in the ViewRowImpl class to accept the value as a method parameter and then pass the value in through the binding layer or when invoking the method from your bean class.