如果缺少模板，则会显示更好的错误消息

Question

如果模板在django模板的渲染内部深处丢失，则会出现如下异常。

搜索很长时间后，我发现了虚假的部分：

 {% include form.template_name %}

form.template_name在我的上下文中为空。

如何在不搜索小时的情况下找到相关的模板名称？

我缺少像普通python代码一样的回溯。 “正常”的python追溯显示了包含错误的文件和行。

/home/foo_fm_d/bin/python /usr/local/pycharm-community-4.5/helpers/pycharm/utrunner.py /home/foo_fm_d/src/foo-time/foo_time/tests/unit/views/user/test_preview_of_next_days.py::EditTestCase::test_preview_of_next_days true
Testing started at 09:26 ...

Error
Traceback (most recent call last):
  File "/home/foo_fm_d/src/foo-time/foo_time/tests/unit/views/user/test_preview_of_next_days.py", line 11, in test_preview_of_next_days
    self.admin_client.get(url)
  File "/home/foo_fm_d/src/djangotools/djangotools/utils/testutils.py", line 275, in get
    response = super(Client, self).get(path, data, **extra)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/test/client.py", line 473, in get
    response = super(Client, self).get(path, data=data, **extra)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/test/client.py", line 280, in get
    return self.request(**r)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/test/client.py", line 444, in request
    six.reraise(*exc_info)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/core/handlers/base.py", line 137, in get_response
    response = response.render()
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/response.py", line 105, in render
    self.content = self.rendered_content
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/response.py", line 82, in rendered_content
    content = template.render(context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 140, in render
    return self._render(context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 134, in _render
    return self.nodelist.render(context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 840, in render
    bit = self.render_node(node, context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/debug.py", line 78, in render_node
    return node.render(context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/loader_tags.py", line 123, in render
    return compiled_parent._render(context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 134, in _render
    return self.nodelist.render(context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 840, in render
    bit = self.render_node(node, context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/debug.py", line 78, in render_node
    return node.render(context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/loader_tags.py", line 123, in render
    return compiled_parent._render(context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 134, in _render
    return self.nodelist.render(context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 840, in render
    bit = self.render_node(node, context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/debug.py", line 78, in render_node
    return node.render(context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/loader_tags.py", line 62, in render
    result = block.nodelist.render(context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 840, in render
    bit = self.render_node(node, context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/debug.py", line 78, in render_node
    return node.render(context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/debug.py", line 88, in render
    output = self.filter_expression.resolve(context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 585, in resolve
    obj = self.var.resolve(context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 735, in resolve
    value = self._resolve_lookup(context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 789, in _resolve_lookup
    current = current()
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/loader_tags.py", line 72, in super
    return mark_safe(self.render(self.context))
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/loader_tags.py", line 62, in render
    result = block.nodelist.render(context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 840, in render
    bit = self.render_node(node, context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/debug.py", line 78, in render_node
    return node.render(context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/loader_tags.py", line 62, in render
    result = block.nodelist.render(context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 840, in render
    bit = self.render_node(node, context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/debug.py", line 78, in render_node
    return node.render(context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/loader_tags.py", line 62, in render
    result = block.nodelist.render(context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/base.py", line 840, in render
    bit = self.render_node(node, context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/debug.py", line 78, in render_node
    return node.render(context)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/loader_tags.py", line 166, in render
    template = get_template(template_name)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/loader.py", line 138, in get_template
    template, origin = find_template(template_name)
  File "/home/foo_fm_d/local/lib/python2.7/site-packages/django/template/loader.py", line 131, in find_template
    raise TemplateDoesNotExist(name)
TemplateDoesNotExist


Process finished with exit code 0

更新资料

我的个人背景：到目前为止，我避免使用django模板，因为有时会默默地忽略异常，并且这样的回溯使调试过程感觉就像穿着沉重的混凝土鞋。

我试图摆脱偏见。 或至少找到一种方法，如何从模板中获取更好的错误消息。

更新二

我通过pyCharm中的unittest看到了回溯。 我没有阅读视图的结果。 “ Webbrowser”客户端调用该视图。 我设置TEMPLATE_DEBUG = True，但是结果是相同的。

Answer 1

之所以看不到通常的Python堆栈跟踪，是因为Django模板不是Python。

它是一种特定的语言，其本身由Python解释，该语言根据模板构建抽象语法树，然后在渲染阶段评估该树。 此时，默认情况下无法访问与源关联的信息（例如，模板文件）。

Django中有一个选项可以显示与渲染模板时引发的异常相关的更多相关信息，DJango 1.8之前是TEMPLATE_DEBUG 。

参见https://docs.djangoproject.com/en/1.8/ref/settings/#template-debug

Django 1.8更改了此选项，并引入了多个模板引擎，因为调试信息特定于模板引擎的每种实现。

编辑：另请参阅Django的TEMPLATE_DEBUG设置是什么？

Answer 2

老实说，我一直在使用其他发布者建议的实时服务器机制。 但是，由于您正在寻找一种可能在Jenkins中可用的解决方案，并且您的堆栈显示您正在通过debug.py进行操作，因此我在那儿查看了调试数据。

我注意到模板引擎应该在Exception的django_template_source属性中为模板的失败部分添加源代码片段。

这是您的例外情况并且对您有帮助吗？ 如果是这样，您可以在UT失败之前捕获异常并进行打印。

Answer 3

当您似乎在使用PyCharm时，可以使用调试器，该调试器允许您查看模板的上下文（为此放置断点） 文档

另外，您正在使用哪个版本的Django？ 在我的（python3.4上的1.8）中，loader.py文件中没有find_template（）。 由于这个原因，它可能已被删除？

顺便说一句，TemplateDoesNotExist似乎总是以模板名称作为参数来调用，我想是因为它能够在错误消息中显示它，但是在您的情况下，它为空。 也许是它很难调试的另一个原因吗？