[Zope-dev] [Zope] Problem with adding importable modules

[David Thibault]

Hello all,

I originally sent this one just to the zope@zope.org list, but I just saw a bug report similar to this about 2.5.b2 on the Zope collector at http://collector.zope.org/Zope/77, so I figured I'd also submit it to you.  I'm running 2.5.0-src (see traceback below). 

I have a problem regarding allowing the import of extra modules.  I've found
various examples (like the "Allowing Import of Modules" in the Zope online
help) and a mailing list item entitled "Import Libraries into Python Script"
(http://lists.zope.org/pipermail/zope-dev/2001-February/009531.html), but
these aren't helping me.  I'm still getting this error.  

I'm trying to use the Reportlab toolkit from within a Zope script (NOT an
external method).  I DON'T want to just import the whole Reportlab toolkit,
because within that toolkit there are sys and os sections with what appear
to contain very dangerous items.  Therefore, I'm following more along the
lines of the help in the Zope online help.  I created a folder called
MyScriptModules in $ZOPE/lib/python/Products/.  The __init__.py file therein
looks like this:

-------------contents of __init__.py-------------------------------------
from Products.PythonScripts.Utility import allow_module, allow_class
from AccessControl import ModuleSecurityInfo, ClassSecurityInfo
from Globals import InitializeClass
from reportlab import platypus
from reportlab.lib import colors, enums, pagesizes, styles, units
from reportlab.pdfgen.canvas import Canvas
allow_class(Canvas)
allow_class(platypus)
allow_class(colors)
allow_class(enums)
allow_class(pagesizes)
allow_class(styles)
allow_class(units)
ModuleSecurityInfo('reportlab').declarePublic('platypus')
ModuleSecurityInfo('reportlab.lib').declarePublic('colors','enums','pagesize
s','
styles','units')
ModuleSecurityInfo('reportlab.pdfgen.canvas').declarePublic('Canvas')
-------------end __init__.py contents---------------------------------

I only wanted to import the bare essentials of my current program and some
other classes that looked harmless but useful (like colors, enums, etc).  I
first started with ReportLab by creating a shell-based python script, which
ran perfectly and created my PDF file.  Now I'm porting it to Zope and I'm
getting errors.  Here's a curtailed example of the script.  This short
example creates the same error I'm getting in the full version of the
script:

------------begin sample problem script-----------------------------
#_______DO ALL THE IMPORTS__________________________________________________
from reportlab import platypus
from reportlab.lib import styles, units, pagesizes
from reportlab.pdfgen.canvas import Canvas
import string
#_______END IMPORTS SECTION_________________________________________________


#_______SET UP GLOBAL VARIABLES_____________________________________________
PAGE_WIDTH = pagesizes.letter[0]
PAGE_HEIGHT = pagesizes.letter[1]
txt_styles = styles.getSampleStyleSheet()
styleTITLE = txt_styles['Heading1']
#_______END GLOBAL VARIABLES________________________________________________

return "I didn't crash" 

-----------------------end sample problem script---------------------------

When I try to test it Zope tries to make me log in again, I do so, and it
asks me to log in repeatedly.  If I finally click "Cancel", it gives me
this:
------------------begin error condition
experienced---------------------------
Zope Error

Zope has encountered an error while publishing this resource.

Error Type: Unauthorized
Error Value: You are not allowed to access Heading1 in this context

(cut out "Troubleshooting Suggestions")

Traceback (innermost last):
  File /usr/local/Zope-2.5.0-src/lib/python/ZPublisher/Publish.py, line 150,
in publish_module
  File /usr/local/Zope-2.5.0-src/lib/python/ZPublisher/Publish.py, line 114,
in publish
  File /usr/local/Zope-2.5.0-src/lib/python/Zope/__init__.py, line 158, in
zpublisher_exception_hook
    (Object: feedback)
  File /usr/local/Zope-2.5.0-src/lib/python/ZPublisher/Publish.py, line 98,
in publish
  File /usr/local/Zope-2.5.0-src/lib/python/ZPublisher/mapply.py, line 88,
in mapply
    (Object: test.py)
  File /usr/local/Zope-2.5.0-src/lib/python/ZPublisher/Publish.py, line 39,
in call_object
    (Object: test.py)
  File /usr/local/Zope-2.5.0-src/lib/python/Shared/DC/Scripts/Bindings.py,
line 252, in __call__
    (Object: test.py)
  File /usr/local/Zope-2.5.0-src/lib/python/Shared/DC/Scripts/Bindings.py,
line 283, in _bindAndExec
    (Object: test.py)
  File
/usr/local/Zope-2.5.0-src/lib/python/Products/PythonScripts/PythonScript.py,
line 291, in _exec
    (Object: test.py)
    (Info: ({'script': <PythonScript instance at 8ed0008>, 'context':
<Folder instance at 8ecd2d0>, 'container': <Folder instance at 8ecd2d0>,
'traverse_subpath': []}, (), {}, None))
  File Script (Python), line 17, in test.py
  File /usr/local/Zope-2.5.0-src/lib/python/AccessControl/ZopeGuards.py,
line 94, in guarded_getitem
Unauthorized: (see above)

------------------end error condition
experienced-----------------------------

It never returns the phrase "I didn't crash."  However, if I comment out the
line "styleTITLE = txt_styles['Heading1']" it does complete successfully.
That means that the "pagesizes" stuff did import properly, because the
PAGE_HEIGHT and PAGE_WIDTH get calculated properly (I can even return those
successfully).  Sorry for the long email, but I wanted to give a complete
description of what I'm up against here.  I suspect there's some problem in
my __init__.py that's preventing me from accessing subobjects of what I've
imported, but I'm not sure how to resolve it.

Thanks,
Dave

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