Traceback on automatic sticker printing in batch context

[xispa]

Description of the issue/feature this PR addresses

Traceback on rendering stickers from inside batch context on AR receive.

Linked issue: #671

Current behavior before PR

The following traceback appears in stickers preview:

Traceback (most recent call last):
  File "/home/xispa/zinstance/src/senaite.core/bika/lims/browser/stickers.py", line 295, in renderItem
    return embed(self)
  File "/home/xispa/buildout-cache/eggs/Zope2-2.13.26-py2.7.egg/Products/Five/browser/pagetemplatefile.py", line 59, in __call__
    sourceAnnotations=getattr(debug_flags, 'sourceAnnotations', 0),
  File "/home/xispa/buildout-cache/eggs/zope.pagetemplate-3.6.3-py2.7.egg/zope/pagetemplate/pagetemplate.py", line 132, in pt_render
    strictinsert=0, sourceAnnotations=sourceAnnotations
  File "/home/xispa/buildout-cache/eggs/five.pt-2.2.4-py2.7.egg/five/pt/engine.py", line 98, in __call__
    return self.template.render(**kwargs)
  File "/home/xispa/buildout-cache/eggs/z3c.pt-3.1.0-py2.7.egg/z3c/pt/pagetemplate.py", line 158, in render
    return base_renderer(**context)
  File "/home/xispa/buildout-cache/eggs/Chameleon-3.2-py2.7.egg/chameleon/zpt/template.py", line 297, in render
    return super(PageTemplate, self).render(**_kw)
  File "/home/xispa/buildout-cache/eggs/Chameleon-3.2-py2.7.egg/chameleon/template.py", line 191, in render
    raise_with_traceback(exc, tb)
  File "/home/xispa/buildout-cache/eggs/Chameleon-3.2-py2.7.egg/chameleon/template.py", line 171, in render
    self._render(stream, econtext, rcontext)
  File "9d67db03324cd1649323746712e6c6a8.py", line 152, in render
AttributeError: 'NoneType' object has no attribute 'getSampler'

 - Expression: "        python:sample.getS"
 - Filename:   ... /bika/lims/browser/templates/stickers/Code_128_1x48mm.pt
 - Location:   (line 26: col 14)
 - Source:     sampler           python:sample.getSampler();
                         ^^^^^^^^^^^^^^^^^^^^^^^^^^
 - Arguments:  modules: 
               sample: 
               ar: 
               container: 
               wrapped_repeat: 
               portal_url: http://localhost:8080/senaite
               traverse_subpath: 
               partnr: 001
               template: 
               translate: 
               repeat: {...} (0)
               views: 
               args: 
               here: 
               part: 
               user: 
               nothing: 
               ar_id: 
               default: 
               request: 
               item: 
               loop: {...} (0)
               context: 
               portal_state: 
               view: 
               root: 
               options: {...} (0)
               target_language:

Desired behavior after PR is merged

The PDF with the stickers correctly rendered for the received Analysis Requests is displayed

--
I confirm I have tested this PR thoroughly and coded it according to PEP8
and Plone's Python styleguide standards.

[ramonski]

Thanks for removing that backslash madness, which always looks to me like a huge regular expression. Finally, I can understand that little piece of code:)

However, looking at the return value return len(transitioned), dest I see nowhere this dest value set differently than None. So I don't understand that logic what happens then. Should dest be self.destination_url?

We should really get away from using classes as multi-state-machines with implicit usage of instance variables, always gives me headaches...

[xispa]

To be honest, did not recall on that "dest" variable. Since the redirection is managed by workflow_action_print_stickers, I think it should be totally safe to remove this dest, but I will check if anyone is expecting this tuple return (I'd say that no one).

[xispa]

In any case, there is no sense to have this whole logic inside submitTransition, especially because this workflow logic should not live inside bika_listing imo, rather in workflow.<portal_type>.events.* . I will take care of this soon.

[ramonski]

Yes, this logic needs to go out from the listing code, agree.
I think so as well that other places handle that None URL gracefully, at least the places I can remember. So I'm fine to let that in, ok?

[xispa]

Ok, then I will just do dest = self.destination_url (its value is already assigned in workflow_action_print_stickers) as a temporary solution until we get rid of this crap.