从Django 1.11 迁移到 Django 2.2 后 AdminFileWidget 的 render 报错了：
代码语言：javascript复制TypeError: render() got an unexpected keyword argument 'renderer'
(41 additional frame(s) were not displayed)
...
File "django/template/base.py", line 993, in render
return render_value_in_context(output, context)
File "django/template/base.py", line 972, in render_value_in_context
value = str(value)
File "django/utils/html.py", line 388, in <lambda>
klass.__str__ = lambda self: mark_safe(klass_str(self))
File "django/forms/boundfield.py", line 33, in __str__
return self.as_widget()
File "django/forms/boundfield.py", line 93, in as_widget
renderer=self.form.renderer,解决办法：
代码语言：javascript复制class AdminImageWidget(AdminFileWidget):
# django 2.2
# def render(self, name, value, attrs=None, renderer=None):
# """Render the widget as an HTML string."""
# context = self.get_context(name, value, attrs)
# return self._render(self.template_name, context, renderer)
# def render(self, name, value, attrs=None): # django 1.11
def render(self, name, value, attrs=None, renderer=None): # django 2.2
output = []
if value and getattr(value, "url", None):
image_url = value.url
file_name = str(value)
# output.append(u' <a href="%s" target="_blank"><img src="%s" alt="%s" /></a> %s ' %
# (image_url, image_url, file_name, _('Change:')))
output.append(u' <a href="%s" target="_blank"><img src="%s" alt="%s" /></a>' %
(image_url, image_url, file_name))
output.append(super(AdminFileWidget, self).render(name, value, attrs))
return mark_safe(u''.join(output))widgets.py 的路径：
../lib/python3.6/site-packages/django/forms/widgets.py -> 239 行左右
