pabigot/pyxb

UnboundElementError when trying to subclass

bavovanachte opened this issue · 3 comments

bavovanachte commented

I've made a working example of a ReqIf XML output with just the classes generated by pyxb.

Now, I wanted to subclass some of these classes to hide some of the pyxb.BIND() function calls (and add more functionality), but ran into some issues when trying to call a.toxml() later on.

Below is the way I've defined the subclass. I think I did it the same way as described here, but it gives me the following error:

Traceback (most recent call last):
  File "ReqIF.py", line 95, in <module>
    print(a.toxml());
  File "/home/bvn/.pyenv/versions/3.6.10/lib/python3.6/site-packages/pyxb/binding/basis.py", line 560, in toxml
    dom = self.toDOM(bds, element_name=element_name)
  File "/home/bvn/.pyenv/versions/3.6.10/lib/python3.6/site-packages/pyxb/binding/basis.py", line 528, in toDOM
    raise pyxb.UnboundElementError(self)
pyxb.exceptions_.UnboundElementError: Instance of type {http://www.omg.org/spec/ReqIF/20110401/reqif.xsd}REQ-IF has no bound element for start tag

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "ReqIF.py", line 97, in <module>
    print(e.details())
AttributeError: 'UnboundElementError' object has no attribute 'details'

The code:

class REQ_IF_x(REQ_IF_):
    def __init__(self):
        super().__init__(
            THE_HEADER=pyxb.BIND(),
            CORE_CONTENT=pyxb.BIND(),
            TOOL_EXTENSIONS=pyxb.BIND(),
        )

REQ_IF_._SetSupersedingClass(REQ_IF_x)

# Construct the header
a = REQ_IF_x()
header = REQ_IF_HEADER(
    IDENTIFIER = "abcd",
    COMMENT = "abcd",
    CREATION_TIME = dateTime.today(),
    REPOSITORY_ID = "",
    REQ_IF_TOOL_ID = "",
    REQ_IF_VERSION = "1.0",
    SOURCE_TOOL_ID = "",
    TITLE = "")
a.THE_HEADER.REQ_IF_HEADER=header

# More code for initializing fields

try:
    print(a.toxml());
except Exception as e:
    print(e.details())

Could you give me some pointers as to what I'm doing wrong and how I can still achieve the intended goal? I assume it's related to the super constructor somehow?

bavovanachte commented

For clarity: this is based on the reqif bundle generated out of pyxb

bavovanachte commented

Also, I am able to subclass other classes from the bindings. I've tried REQ_IF_CONTENT and REQ_IF_HEADER with constructors.

I guess the difficulty comes from the fact that there is both a REQ_IF_ and a REQ_IF version? This doesn't seem to be the case for the other classes.

class REQ_IF_ (pyxb.binding.basis.complexTypeDefinition):
    """Complex type {http://www.omg.org/spec/ReqIF/20110401/reqif.xsd}REQ-IF with content type ELEMENT_ONLY"""
   ...

REQ_IF = pyxb.binding.basis.element(pyxb.namespace.ExpandedName(_Namespace, 'REQ-IF'), REQ_IF_, location=pyxb.utils.utility.Location('/home/bvn/Projects/git/pyxb/pyxb/bundles/reqif/schemas/reqif.xsd', 8, 2))
_Namespace.addCategoryObject('elementBinding', REQ_IF.name().localName(), REQ_IF)