使用& quot; if& quot;在带有多个参数的自定义模板标签的模板中 [英] Use of "if" in template with custom template tag with multiple arguments

问题描述

我写了一个自定义模板标签来查询数据库，并检查数据库中的值是否与给定的字符串匹配:

I wrote a custom template tag to query my database and check if the value in the database matches a given string:

@register.simple_tag
def hs_get_section_answer(questionnaire, app, model, field, comp_value):

    model = get_model(app, model)
    modal_instance = model.objects.get(questionnaire=questionnaire)

    if getattr(modal_instance, field) == comp_value:
        return True
    else:
        return False

在我的模板中，我可以按以下方式使用此标记:

In my template I can use this tag as follows:

{% hs_get_section_answer questionnaire 'abc' 'def' 'ghi' 'jkl' %}

该函数正确返回True或False.

The function returns True or False correctly.

我的问题:我想做这样的事情:

My problem: I'd like to do something like this:

{% if hs_get_section_answer questionnaire 'abc' 'def' 'ghi' 'jkl' %}
  SUCCESS
{% else %}
  FAILURE
{% endif %}

但这是行不通的；好像"if"模板标签无法处理多个参数.

But this does not work; it seems as if the "if" template tag cannot handle multiple arguments.

有人可以给我提示如何解决这个问题吗?

Can anybody give me a hint how to solve this problem?

推荐答案

将模板标签调用的结果设置为变量，然后对该结果调用{％if％}

Set the result of the template tag call to a variable then call {% if %} on that result

{% hs_get_section_answer questionnaire 'abc' 'def' 'ghi' 'jkl' as result %}
{% if result %}
...
{% endif %}

您还需要更改模板标签以使用分配标签而不是简单标签.请参阅任务标签django doc: https://docs.djangoproject.com/en/dev/howto/custom-template-tags/#assignment-tags

You will also need to change your template tag to use an assignment tag instead of a simple tag as well. See assignment tags django doc: https://docs.djangoproject.com/en/dev/howto/custom-template-tags/#assignment-tags

@register.assignment_tag
def hs_get_section_answer(questionnaire, app, model, field, comp_value):

  model = get_model(app, model)
  modal_instance = model.objects.get(questionnaire=questionnaire)

  if getattr(modal_instance, field) == comp_value:
    return True
  else:
    return False

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