erp5_hal_json_style: get last form from correct document
last form was rendering on web section context, which can cause KeyError, such as(on zope-event.log):
2023-01-05 15:03:23,112 WARNING ERP5Form Field.get_value <ProxyField at /erp5/DataProduct_view/my_default_image_absolute_url> [enabled], exception on tales_expr:
Traceback (most recent call last):
File "/srv/slapgrid/slappart13/srv/runner/software/30bf51a45c59c0ef5619ff206a304e5b/parts/erp5/product/ERP5Form/Form.py", line 224, in __call__
value = self.tales_expr.__of__(field)(**kw)
File "/srv/slapgrid/slappart13/srv/runner/software/30bf51a45c59c0ef5619ff206a304e5b/parts/erp5/product/Formulator/TALESField.py", line 58, in __call__
return getEngine().getContext(kw).evaluate(expr)
File "/srv/slapgrid/slappart13/srv/runner/software/30bf51a45c59c0ef5619ff206a304e5b/eggs/zope.tales-3.5.3-py2.7.egg/zope/tales/tales.py", line 696, in evaluate
return expression(self)
File "/srv/slapgrid/slappart13/srv/runner/software/30bf51a45c59c0ef5619ff206a304e5b/eggs/zope.tales-3.5.3-py2.7.egg/zope/tales/expressions.py", line 217, in __call__
return self._eval(econtext)
File "/srv/slapgrid/slappart13/srv/runner/software/30bf51a45c59c0ef5619ff206a304e5b/eggs/Zope2-2.13.30-py2.7.egg/Products/PageTemplates/Expressions.py", line 147, in _eval
ob = self._subexprs[-1](econtext)
File "/srv/slapgrid/slappart13/srv/runner/software/30bf51a45c59c0ef5619ff206a304e5b/eggs/zope.tales-3.5.3-py2.7.egg/zope/tales/expressions.py", line 124, in _eval
ob = self._traverser(ob, element, econtext)
File "/srv/slapgrid/slappart13/srv/runner/software/30bf51a45c59c0ef5619ff206a304e5b/eggs/Zope2-2.13.30-py2.7.egg/Products/PageTemplates/Expressions.py", line 74, in boboAwareZopeTraverse
object = object.restrictedTraverse(name)
File "/srv/slapgrid/slappart13/srv/runner/software/30bf51a45c59c0ef5619ff206a304e5b/eggs/Zope2-2.13.30-py2.7.egg/OFS/Traversable.py", line 317, in restrictedTraverse
return self.unrestrictedTraverse(path, default, restricted=True)
File "/srv/slapgrid/slappart13/srv/runner/software/30bf51a45c59c0ef5619ff206a304e5b/eggs/Zope2-2.13.30-py2.7.egg/OFS/Traversable.py", line 285, in unrestrictedTraverse
raise e
KeyError: 'getDefaultImageAbsoluteUrl'