#298 TaurusNeXusBrowser errors

[Jan Kotanski]

Hi,

I was looking at TaurusNeXusBrowser and I noticed that it throws a lot of Exceptions, e.g.

1) when there is unresolved link in a NeXus group there is not possible to look at least at other fields/links of this group but one get the following error:

MainThread     ERROR    2016-06-03 13:45:24,771 LogExceptHook: Unhandled exception:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/PyMca/HDF5Widget.py", line 434, in rowCount
    return len(self.getProxyFromIndex(index))
  File "/usr/lib/python2.7/dist-packages/PyMca/HDF5Widget.py", line 296, in __len__
    return len(self.children)
  File "/usr/lib/python2.7/dist-packages/PyMca/HDF5Widget.py", line 195, in children
    items[i][0])
AttributeError: 'NoneType' object has no attribute '_posixPath'

2) on viewing a string field one gets an infinite sequence of errors:

MainThread     ERROR    2016-06-03 13:47:29,635 LogExceptHook: Unhandled exception:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/PyMca/NumpyArrayTableModel.py", line 52, in data
    return self._data(index, role)
  File "/usr/lib/python2.7/dist-packages/PyMca/NumpyArrayTableModel.py", line 65, in _data1D
    return MyQVariant(self._format % self._array[col])
TypeError: float argument required, not unicode

3) a preview error

MainThread     ERROR    2016-06-03 11:58:16,882 LogExceptHook: Unhandled
exception:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/taurus/qt/qtgui/extra_nexus/taurusnexuswidget.py",
line 114, in onHDF5WidgetSignal
    self.__currentPreview = self.neXusPreviewWidgetFactory(ddict)
  File
"/usr/lib/python2.7/dist-packages/taurus/qt/qtgui/extra_nexus/taurusnexuswidget.py",
line 132, in neXusPreviewWidgetFactory
    info = HDF5Info.getInfo(self.__nexusFile,ddict["name"])
  File "/usr/lib/python2.7/dist-packages/PyMca/HDF5Info.py", line 418,
in getInfo
    memberObject = hdf5File[node][member]
  File "/usr/lib/python2.7/dist-packages/h5py/_hl/group.py", line 153,
in __getitem__
    oid = h5o.open(self.id, self._e(name), lapl=self._lapl)
  File "h5o.pyx", line 173, in h5py.h5o.open (h5py/h5o.c:3405)
KeyError: "unable to open object (Symbol table: Can't open object)"

Bests,
Jan

[Jan Kotanski]

The error 2) (inifnite even loop) causes 100% usage of CPU which can be harmful for users.

Of course the infinite loop can be broken by clicking

Don't show this message again

but it may be not straightforward for users.