Example for custom widgets in newforms documentation is subtly wrong

[Christian Tanzer <tanzer@…>]

The example given for a custom widget

class CommentWidget(forms.TextInput):
    def __init__(self, *args, **kwargs):
        kwargs.setdefault('attrs',{}).update({'size': '40'})
        super(CommentWidget, self).__init__(*args, **kwargs)

will silently override further instance-specific customizations for size, e.g.,

comment = forms.CharField(
                widget=CommentWidget(attrs={'size': '80'}))

To avoid this, the example should be written like

class CommentWidget(forms.TextInput):
    def __init__(self, *args, **kwargs):
        attrs = kwargs.setdefault('attrs',{})
        if 'size' not in attrs :
            attrs['size'] = '40'
        super(CommentWidget, self).__init__(*args, **kwargs)

[Malcolm Tredinnick]

(In [7845]) Fixed #7630 -- Slight tweak to the custom form widget exampleto avoid any
confusion. Based on a patch from Christian Tanzer.