Django，模板，循环和循环 [英] Django, templates, for loops, and cycles

问题描述

（底部的tl）

让我尝试解释一下我要完成的工作：我有一个二维数组，我想以某种方式显示其内容。我想要行，并且每行最多只能显示三个对象，因为缺少更好的词。因此，我想遍历数组并在此过程中创建HTML。我的想法是：数组中的每个三个中的第一个元素都应打开行。每三分之三元素应关闭行。但是，如果[inner]数组中的最后一个元素不是恰好是三分之三，则仍应关闭该行。因此，例如，如果我们有类似 L = [[0,1,2,3,4]，[5,6,7]] 的东西，可以这样显示：

Let me try to explain what I'm trying to accomplish: I have a two dimensional array, and I would like to display its contents a certain way. I want "rows", and each row can display no more than three "objects", for lack of a better word. So I want to iterate over the array and create my HTML in the process. My idea is this: every "first of three" elements in the array should open up the "row". Every "third of three" elements should close the "row". However, if the last element in the [inner] array does not happen to be the "third of three", it should still close the row. So, for example, if we had something like L=[ [0,1,2,3,4], [5,6,7] ], I would want to display it like so:

0  1  2
3  4

5  6  7

可能被标记为：

<div>0 1 2</div>
<div>3 4</div>
<div>5 6 7</div>

我的第一个想法是简单地使用模运算符，看看每次迭代是否都是第一个， 第二或第三行，但是Django模板不直接支持模（稍后会详细介绍）。

My first thought was to simply use the modulo operator and see if each iteration was the "first", "second", or "third" of a row, but Django templates don't directly support modulo (more on that later).

所以我想到了这样的模板代码：

So I came up with template code like this:

{% for x in L %}
 {% for y in x %}
  {% cycle '<div>' '' '' %}
   {{ y }}
  {% cycle '' '' '</div>' %}
 {% endfor %}<br/>
{% endfor %}

这是一个好的开始。以上面的示例为例，在 0 上我们将打开一个div，在 1 上不执行任何操作，在 2 关闭div，在 3 上打开，然后在 4 上...好吧，它不会关闭，因为 4 不是 3系列中的第3个。因此，虽然Django模板没有取模，但它们确实有一个dibyby check，因此我想出了另外的逻辑，如果我们点击[inner] for循环的最后一个元素，并且也不能被3整除（因此我们没有重复的关闭），然后关闭div：

And this was a good start. Taking the above example, on 0 we would open a div, on 1 do nothing, on 2 close the div, on 3 open it, and on 4... well, it wouldn't close, because 4 was not the "third in a series of 3". So, while Django templates don't have modulo, they do have a divisibleby check, so I came up with additional logic to say, if we hit the last element of the [inner] for loop, and it also is not divisible by 3 (so we don't have a duplicate close), then close the div:

{% for x in z %}
 {% for y in x %}
  {% cycle '<div>' '' '' %}
   {{ y }}
  {% cycle '' '' '</div>' %}

  {% if forloop.last %}
  {% if forloop.counter|divisibleby:"3" %}
    <!-- Row Already Closed -->
  {% else %}
    </div>
  {% endif %}
  {% endif %}

 {% endfor %}<br/>
{% endfor %}

效果更好！现在，我以正确的标记遍历了整个第一个内部数组。我的问题是：显然，当您超出内部for循环的范围时，Django的循环功能不会重置。这意味着，我在上面示例中的数字 5 并没有像应该打开的div一样，也不被认为是周期中的第一个。实际上，它实际上被认为是第三名，因此它正在关闭div！

This worked better! Now, I got through the whole first inner array with proper markup. My issue is this: apparently, Django's cycle functionality does not reset when you go out of scope of the inner for loop. What this means is, my number 5 from the above example is not opening a div like it should, it is not being recognized as the first in a cycle. In fact, it's actually being recognized as a third, and so it is closing a div!

所以我不确定从这里去哪里。这似乎是 Django中已知和未解决的问题。有人可以帮忙吗？

So I'm not sure where to go from here. This appears to be a known and unfixed issues in Django. Can anyone assist, please?

tl; dr 我想使用二维数组，例如 L = [[0,1,2,3,4]，[5,6,7]] 并正确地将其标记为一次，每次分组最多3个而不将多个数组中的任何元素分组在一起，就像这样：

tl;dr I want to take a 2d array, e.g. L=[ [0,1,2,3,4], [5,6,7] ] and properly mark it up grouping no more than 3 at a time and without grouping any elements from multiple arrays together, like so:

0  1  2
3  4

5  6  7

模板代码是什么，为什么？

What would be the template code for that and why?

推荐答案

您应该能够使用 {％，如果forloop.counter0 | dibyby： 3％ } 确定何时打开< div> 标记，以及 {％如果是forloop.last或forloop.counter | dibyby： 3％} 确定何时关闭< / div> 标记。

You should be able to use {% if forloop.counter0|divisibleby:"3" %} to determine when to open the <div> tag, and {% if forloop.last or forloop.counter|divisibleby:"3" %} to determine when to close the </div> tag.

{% for x in z %}
 {% for y in x %}
  {% if forloop.counter0|divisibleby:"3" %}<div>{% endif %}
   {{ y }}
  {% if forloop.last or forloop.counter|divisibleby:"3" %}</div>{% endif %}
 {% endfor %}<br/>
{% endfor %}

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