Silent crash in forms rendering

[stilldodge]

Given form as follows, as_table crashes

I expect this has to do with collisions to properties of Form and variations of problems will probably happen with (errors, changed_data, media)

class TestForm(forms.ModelForm):
    errors = forms.CharField(widget=forms.HiddenInput)
    class Meta:
        model = MyModel

Stack trace

c:\django\django\forms\forms.py in as_table(self)
    175     def as_table(self):
    176         "Returns this form rendered as HTML <tr>s -- excluding the <table></table>."
--> 177         return self._html_output(u'<tr><th>%(label)s</th><td>%(errors)s%(field)s%(help_text)s</td></tr>', u'<tr><td colsp
"2">%s</td></tr>', '</td></tr>', u'<br />%s', False)
    178
    179     def as_ul(self):

c:\django\django\forms\forms.py in _html_output(self, normal_row, error_row, row_ender, help_text_html, errors_on_separate_row)
    131     def _html_output(self, normal_row, error_row, row_ender, help_text_html, errors_on_separate_row):
    132         "Helper function for outputting HTML. Used by as_table(), as_ul(), as_p()."
--> 133         top_errors = self.non_field_errors() # Errors that should be displayed above all fields.
    134         output, hidden_fields = [], []
    135         for name, field in self.fields.items():

c:\django\django\forms\forms.py in non_field_errors(self)
    191         are none.
    192         """
--> 193         return self.errors.get(NON_FIELD_ERRORS, self.error_class())
    194
    195     def full_clean(self):

AttributeError: 'CharField' object has no attribute 'get'

[Malcolm Tredinnick]

Fixed description formatting.

[Malcolm Tredinnick]

I strongly suspect this was fixed in [8618].

[stilldodge]

With latest 8880 svn this still happens, this is based on current ModelForm docs for overriding fields

class TestModel(models.Model):
    errors = models.CharField(max_length=100)

tm = TestModel()

class TestForm(forms.ModelForm):
    errors=forms.CharField(widget=forms.HiddenInput)

    class Meta:
        model = TestModel

tf=TestForm(tm)

tf.as_table()

In [9]: tf.as_table()
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)

C:\dev\scms\<ipython console> in <module>()

c:\django\django\forms\forms.py in as_table(self)
    181     def as_table(self):
    182         "Returns this form rendered as HTML <tr>s -- excluding the <table></table>."
--> 183         return self._html_output(u'<tr><th>%(label)s</th><td>%(errors)s%(field)s%(help_text)s</td></tr>', u'<tr><td colspan=
"2">%s</td></tr>', '</td></tr>', u'<br />%s', False)
    184
    185     def as_ul(self):

c:\django\django\forms\forms.py in _html_output(self, normal_row, error_row, row_ender, help_text_html, errors_on_separate_row)
    137     def _html_output(self, normal_row, error_row, row_ender, help_text_html, errors_on_separate_row):
    138         "Helper function for outputting HTML. Used by as_table(), as_ul(), as_p()."
--> 139         top_errors = self.non_field_errors() # Errors that should be displayed above all fields.
    140         output, hidden_fields = [], []
    141         for name, field in self.fields.items():

c:\django\django\forms\forms.py in non_field_errors(self)
    197         are none.
    198         """
--> 199         return self.errors.get(NON_FIELD_ERRORS, self.error_class())
    200
    201     def full_clean(self):

c:\django\django\forms\forms.py in _get_errors(self)
    109         "Returns an ErrorDict for the data provided for the form"
    110         if self._errors is None:
--> 111             self.full_clean()
    112         return self._errors
    113     errors = property(_get_errors)

c:\django\django\forms\forms.py in full_clean(self)
    216             # Each widget type knows how to retrieve its own data, because some
    217             # widgets split data over several HTML fields.
--> 218             value = field.widget.value_from_datadict(self.data, self.files, self.add_prefix(name))
    219             try:
    220                 if isinstance(field, FileField):

c:\django\django\forms\widgets.py in value_from_datadict(self, data, files, name)
    168         of this widget. Returns None if it's not provided.
    169         """
--> 170         return data.get(name, None)
    171
    172     def _has_changed(self, initial, data):

AttributeError: 'TestModel' object has no attribute 'get'

In [10]:

[Michael Radziej]

I can confirm that this is still an open bug (after changeset r8877)

[Malcolm Tredinnick]

This is just an error. If you're trying to create a form using an instance, you have to call

TestForm(instance=tm)

That's ​documented here, so at least the current documentation is correct.

[Jacob]

Milestone 1.0 deleted