Django 模板循环交替行 - 无循环

Question

也许这是一个没有问题的问题，但是当您不在循环中时，如何使用 Django {% Cycle %} 功能或类似的功能？具体来说，我有一个手写的 HTML 表，因为它不是您需要在循环中执行的操作。我希望行交替，如下所示:

   <tr class="{% cycle 'even' 'odd'%}"></tr>
   <tr class="{% cycle 'even' 'odd'%}"></tr>
   <tr class="{% cycle 'even' 'odd'%}"></tr>

但是我没有使用循环，所以这总是会产生even。我不希望出现这样的情况:我想稍后插入一行，然后必须手动更改其下方所有行的类。我只是小气吗？您将如何在不循环的情况下循环？

Answer 1

有一节专门讨论在 the docs 上的循环之外使用 cycle :

In some cases you might want to refer to the next value of a cycle from outside of a loop. To do this, just give the {% cycle %} tag a name, using "as", like this:

{% cycle 'row1' 'row2' as rowcolors %}

From then on, you can insert the current value of the cycle wherever you'd like in your template by referencing the cycle name as a context variable. If you want to move the cycle onto the next value, you use the cycle tag again, using the name of the variable. So, the following template:

<tr>
    <td class="{% cycle 'row1' 'row2' as rowcolors %}">...</td>
    <td class="{{ rowcolors }}">...</td>
</tr>
<tr>
    <td class="{% cycle rowcolors %}">...</td>
    <td class="{{ rowcolors }}">...</td>
</tr>

would output:

<tr>
    <td class="row1">...</td>
    <td class="row1">...</td>
</tr>
<tr>
    <td class="row2">...</td>
    <td class="row2">...</td>
</tr>

因此，在您的情况下，您只需声明一次，然后在每一行调用 {% Cycle name %} 。