过滤器无效：＆＃39;修订版＆＃39;

Question

使用以下代码时：

 {% with ""|add:revision.width|add:"x"|revision.height as dimensions %}


 {% thumbnail revision.image dimensions as thumb %}
 {% endwith %}

我收到以下错误：

Django Version: 1.6.11
Exception Type: TemplateSyntaxError
Exception Value:    
Invalid filter: 'revision'
Exception Location: /usr/local/lib/python2.7/site-packages/django/template/base.py in find_filter, line 366
Python Executable:  /usr/local/bin/python
Python Version: 2.7.9

为什么呢？我该怎么做才能解决它？

Answer 1

问题是链中最后一次应用的过滤器（revision.height）。

替换：

{% with ""|add:revision.width|add:"x"|revision.height as dimensions %}

使用：

{% with ""|add:revision.width|add:"x"|add:revision.height as dimensions %}

---

您还可以将变量分配给revision.width和revision.height：

{% with width=revision.width height=revision.height %}
    {% with ""|add:width|add:"x"|add:height as dimensions %}
        ...
    {% endwith %}
{% endwith %}