History for PlannedBehavior

??changed:
-
Python Methods Planned Behavior

  - uses GuardedBlock for security

  - copies methods from !DocumentTemplate.DT_Util.!TemplateDict into the
  builtins dictionary

  - uses the Bindings tab to make the container, context, method object,
  caller's DTML namespace, and traversal information available through
  user-chosen names.

  - recurses into code blocks, allowing lambdas and nested function 
  definitions.

GuardedBlock security

  - 'co_names' is checked for multi-character names beginning with "_".

  - 'print' statements are replaced with calls to a function that stores
  the text in a list.  The concatenation of these strings is available
  through global variable 'printed'.  If 'printed' is not read, but 'print'
  statements are used, a warning is printed.

  - assignments to attributes, items, or slices are replaced
  with calls to methods of the container.  These are named 
  '__guarded_setattr__', '__guarded_setitem__', and '__guarded_setslice__'.

  - 'del' statements that operate on attributes, items, or slices are
  replaced with calls to methods of the container.  These are named 
  '__guarded_delattr__', '__guarded_delitem__', and '__guarded_delslice__'.

  - Literal lists and dictionaries are exempted from this wrapping, as are
  objects which declare that they handle their own write security, by
  exposing a true '_guarded_writes' attribute.

  - 'return', 'assert', 'try/finally', 'try/except/else', 'pass', 'raise',
  'break', 'global', and 'if/elif/else' are not changed or
  restricted.

  - 'for/else', 'while/else', and 'continue' statements have calls to a
  global iteration counter/termination polling function inserted just
  before the jump to the start of a loop.

  - 'import' is restricted by providing an '__import__' function which
  only succeeds if each module to be imported is already in 'sys.modules'.
  Access to names within modules is protected by calling the security
  machinery.

  - 'exec' statements are not allowed.

  - The only other statements are expression statements.  Expression
  evaluation is altered so that multiplication operations are replaced
  with calls to 'careful_mul' from '!DocumentTemplate.!VSEval'. All
  access to attributes, items, and slices is guarded by calls to the
  security machinery.

  - Since CodeBlock compiles a function in an empty global namespace with
  no builtins, the function is flagged restricted, and cannot access
  internal attributes such as 'im_func'.