Jinja2是否支持嵌套if语句?

I read the docs and I am not clear on this is right at all. I know you can use nested for loops, but if statements seem to be different.

我看了医生的资料，我不清楚这是否正确。我知道可以使用嵌套的for循环，但是如果语句看起来不同的话。

Can i do the following?

我能做下面的事吗?

{% if thing=true %}
<div> something here</div>
  {% if diffthing=true %}
  <div> something else</div>
  {% else %}
  <div> third thing</div>
  {% endif %}
{% else %}
<div> nothing here </div>
{% endif %}

Or should the format be different somehow?

或者格式应该有所不同?

3 个解决方案

#1

Jinja2 supports nested blocks, including if statements and other control structures.

Jinja2支持嵌套块，包括if语句和其他控制结构。

See the documentation on Block Nesting and Scope: "Blocks can be nested for more complex layouts."

请参阅有关块嵌套和范围的文档:“块可以嵌套用于更复杂的布局。”

A good use case for this is writing macros that conditionally output HTML:

一个好的用例是编写有条件输出HTML的宏:

{# A macro that generates a list of errors coming back from wtforms's validate function #}
{% macro form_error_summary(form, li_class='bg-danger') %}
    {# only do the following on error... #}
    {% if form.errors %}

        <ul class="errors">

        {# you can do layers of nesting as needed to render your content #}
        {% for _field in form %}
            {% if _field.errors %}
                {% for error in _field.errors %}                 
                    <li class={{li_class}}>{{_field.label}}: {{ error|e }}</li>
                {% endfor %}
            {% endif %}
        {% endfor %}
        </ul>

    {% endif %}
{% endmacro %}

#2

It seem possible. Refer to the documentation here: http://jinja.pocoo.org/docs/templates/#if

这看起来可能的。参考这里的文档:http://jinja.pocoo.org/docs/templates/#if

#3

The answer is yes.

答案是肯定的。

I'm using logic very similar to yours in a live application and the nested if blocks work as expected. It can get a little confusing if you don't keep your code clean, but it works fine.

我在动态应用程序中使用的逻辑与您的非常相似，嵌套的if块按预期工作。如果您不保持代码的整洁，它可能会有点混乱，但是它工作得很好。

#1