7.7.2 SessionBase

##
7.7.2 SessionBase

The `SessionBase` class provides base session handling functionality which is used by all standard Albatross execution context session mixin classes.

`__init__`( | )

  When you inherit from the `SessionBase` class you must call this constructor.

  The class maintains a dictionary of all names from the execution context local namespace which belong in the session. This dictionary is restored along with the session when the session is decoded.

`add_session_vars`( | ...)

  Adds all listed names to the session dictionary. The named variables must exist in the `locals` member or a `SessionError` will be raised.

  The names can optionally be supplied as a list or tuple of names.

`default_session_var`( | name, value)

  Adds a name to the session directory. Sets a value in the local namespace if the name is not already in the local namespace.

`del_session_vars`( | ...)

  Deletes all listed names from the session dictionary.

  The names can optionally be supplied as a list or tuple of names.

`session_vars`( | )

  Returns a list of the names that are currently in the session.

`remove_session`( | )

  Deletes all names from the session dictionary and clears all values from the local namespace via the `clear_locals()` method.

`decode_session`( | text)

  Performs `cPickle.loads()` to retrieve a dictionary of session values. The dictionary is merged into the session local namespace. Adds the keys of the dictionary to the session dictionary.

  Note that an import hook is used around the `cPickle.loads()` to redirect requests to load page modules to the `app.load_page_module()` method. This allows the pickler to find classes which are defined in application page modules. Whether a module is a page module is determined by calling the `app.is_page_module()` method, passing the module name.

`encode_session`( | )

  Builds a dictionary by extracting all local namespace values which are listed in the session dictionary. A test pickle is performed on each value and any unpickleable value is discarded and an error message is written to `sys.stderr`.

  The dictionary is then passed to `cPickle.dumps()` and the result is returned.

`set_save_session`( | flag)

  Sets the flag which controls whether the session will be saved at the end of request processing. By default the internal flag is `TRUE` which means the session will be saved.

`should_save_session`( | )

  Returns the flag which controls whether the session will be saved at the end of request processing.