Hello Lucas,
the problem is in GET_ method of the context attribute.
When event ON_START is executed (my Z event) this GET_ method is called with parameter ITERATOR which IS NOT INITIAL but it does NOT contain any entries, so:
current = iterator->get_current( ).
-> result is that current IS INITIAL -> this results in receiving message '<attribute> not bound'.
Parameter ATTRIBUTE_PATH is not empty it contains string like 'Table[1].<attribute>
So maybe i could use it to retreive my attribute from BOL collection. Im not shure wheter events ON_LINK_CLICK will work correctly later.
Again to mention that BOL collection is filled with the new data.
Maybe somehow to update page context object...