function to create context

[MikeBadescu]

Problem:

our context is a list, the necessary fields are not obvious when constructed with list()

Solution

helper function that has certain named arguments which puts them together in a list

Details

• function name: createContext
• its arguments should include the minimum to create a valid context: e.g. tbl_name, tbl_list, etc
• optional arguments, needed to be provided later (e.g., row_idx for edit mode) should be optional (=NULL)
• its last argument should be ... and attache the list(...) to the returning list
• it should check whether all the fields in xt_lst correspond to field names in tbl_lst