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在Django模板中,如何指定本身是属性的字典键?

django-templates django html python

Kurt Peek · 技术社区 · 7 年前

我正在和一个 ListView 它有两个搜索表单,在视图上下文中称为 search_form ,和过滤器窗体, filter_form .界面如下所示:

两者 search\u表单 以及 filter\u表单 最终更改 列表视图 的 get_queryset 方法我希望这样,当您首先应用过滤器,然后进行搜索时,它将搜索过滤后的结果。

目前,“反向”功能已经实现:当您首先搜索然后过滤时,它将过滤搜索结果。这是因为 input 中的元素 filter\u表单 :

<form action={% url 'dashboard:families' %} method="GET" data-behavior="filters">
                <input type="hidden" name="q" value="{{ request.GET.q.strip }}"/>

                <div class="input-field col s2">
                  {{ filter_form.guide }}
                  <label class="active">Guide</label>
                  {% if filter_form.is_guide_filled %}
                    <a href="" class="clear"><i class="material-icons tiny">clear</i></a>
                  {% endif %}
                </div>

为了进行比较,搜索栏有以下模板, _search.html :

<form action="{% url action %}" method="get" class="left search col s6 hide-on-small-and-down" novalidate>
  <div class="input-field">
    <input id="search" placeholder="{{ placeholder }}"
        autocomplete="off" type="search" name="q"
        value="{{ search_form.q.value.strip|default:'' }}"
        data-query="{{ search_form.q.value.strip|default:'' }}">
    <label for="search" class="active"><i class="material-icons search-icon">search</i></label>
    <i data-behavior="search-clear"
        class="material-icons search-icon"
        {% if not search_form.q.value %}style="display: none;"{% endif %}>close</i>
  </div>
</form>

在主列表视图中, index.html ,搜索模板如下所示:

{% block search_form %}
  {% with action='dashboard:families' placeholder='Search Families' %}
    {% include '_search.html' %}
  {% endwith %}
{% endblock %}

为了使搜索表单保留过滤器,我注意到 guide 仅在现场进行以下工作:

<input type="hidden" name="guide" value="{{ request.GET.guide }}"/>

我想将其概括为包括所有过滤器。我尝试了以下方法:

  {% if filter_form %}
    {% for field in filter_form %}
      {% with field_name=field.name %}
        <input type="hidden" name=field_name value="{{ request.GET.field_name}}"/>
      {% endwith %}
    {% endfor %}
  {% endif %}

但是,如果我尝试这样做,我会在查询字符串中得到“field\u name”:

据我所知 DTL docs ,点表示法实现字典查找、属性查找和列表索引查找。如果我想试试

request.GET.field.name

它可能会在 request.GET 像字典一样的对象,什么也找不到。在常规Python中,我基本上想做的是

request.GET[field.name]

我想我可以用 with 阻止,但显然这不起作用。关于如何实现这一点,有什么建议吗?

使现代化

如果我指定 name 的属性 输入 元素组件 "{{field_name}}" 而不仅仅是 field_name ,就像这样,

<input type="hidden" name="{{field_name}}" value="{{ request.GET.field_name}}"/>

问题是 value 正在设置为空字符串而不是所需的值,这将导致 ValueError 对于 指导 字段(它是 ModelChoiceField 输入应为整数):

在这种情况下,为什么属性查找不起作用?

更新2

对于Lemayzeur的评论,完整的回溯是:

Traceback:

File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/venv/lib/python3.6/site-packages/django/core/handlers/exception.py" in inner
  41.             response = get_response(request)

File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/venv/lib/python3.6/site-packages/django/core/handlers/base.py" in _get_response
  187.                 response = self.process_exception_by_middleware(e, request)

File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/venv/lib/python3.6/site-packages/django/core/handlers/base.py" in _get_response
  185.                 response = wrapped_callback(request, *callback_args, **callback_kwargs)

File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/venv/lib/python3.6/site-packages/django/views/generic/base.py" in view
  68.             return self.dispatch(request, *args, **kwargs)

File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/venv/lib/python3.6/site-packages/two_factor/views/mixins.py" in dispatch
  82.         return super(OTPRequiredMixin, self).dispatch(request, *args, **kwargs)

File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/venv/lib/python3.6/site-packages/django/contrib/auth/mixins.py" in dispatch
  56.         return super(LoginRequiredMixin, self).dispatch(request, *args, **kwargs)

File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/venv/lib/python3.6/site-packages/django/contrib/auth/mixins.py" in dispatch
  92.         return super(PermissionRequiredMixin, self).dispatch(request, *args, **kwargs)

File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/venv/lib/python3.6/site-packages/django/views/generic/base.py" in dispatch
  88.         return handler(request, *args, **kwargs)

File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/dashboard/views/families.py" in get
  74.         return super().get(request, *args, **kwargs)

File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/dashboard/views/base.py" in get
  111.         return super().get(request, *args, **kwargs)

File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/dashboard/views/base.py" in get
  74.         return super().get(request, *args, **kwargs)

File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/venv/lib/python3.6/site-packages/django/views/generic/list.py" in get
  160.         self.object_list = self.get_queryset()

File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/dashboard/views/families.py" in get_queryset
  122.             queryset = queryset.filter(lucy_guide__in=guide)

File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/venv/lib/python3.6/site-packages/django/db/models/query.py" in filter
  784.         return self._filter_or_exclude(False, *args, **kwargs)

File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/venv/lib/python3.6/site-packages/django/db/models/query.py" in _filter_or_exclude
  802.             clone.query.add_q(Q(*args, **kwargs))

File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/venv/lib/python3.6/site-packages/django/db/models/sql/query.py" in add_q
  1250.         clause, _ = self._add_q(q_object, self.used_aliases)

File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/venv/lib/python3.6/site-packages/django/db/models/sql/query.py" in _add_q
  1276.                     allow_joins=allow_joins, split_subq=split_subq,

File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/venv/lib/python3.6/site-packages/django/db/models/sql/query.py" in build_filter
  1206.             condition = lookup_class(lhs, value)

File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/venv/lib/python3.6/site-packages/django/db/models/lookups.py" in __init__
  24.         self.rhs = self.get_prep_lookup()

File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/venv/lib/python3.6/site-packages/django/db/models/fields/related_lookups.py" in get_prep_lookup
  56.                 self.rhs = [target_field.get_prep_value(v) for v in self.rhs]

File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/venv/lib/python3.6/site-packages/django/db/models/fields/related_lookups.py" in <listcomp>
  56.                 self.rhs = [target_field.get_prep_value(v) for v in self.rhs]

File "/Users/kurtpeek/Documents/Dev/lucy/lucy-web/venv/lib/python3.6/site-packages/django/db/models/fields/__init__.py" in get_prep_value
  966.         return int(value)

Exception Type: ValueError at /dashboard/families
Exception Value: invalid literal for int() with base 10: ''

如果我在视图的 get_queryset() 方法,就在堆栈跟踪中的122之前,我看到 指导 确实是一个包含空字符串的空列表,如中所示 self.request.GET :

> /Users/kurtpeek/Documents/Dev/lucy/lucy-web/dashboard/views/families.py(121)get_queryset()
    120 
--> 121         if guide:
    122             queryset = queryset.filter(lucy_guide__in=guide)

ipdb> guide
['']

ipdb> self.request.GET
<QueryDict: {'q': ['Christine'], 'status': [''], 'next_outreach': [''], 'country': [''], 'vip': [''], 'app': [''], 'guide': [''], 'package': ['']}>

除了提交空值的困难之外,我实际上希望 指导 字段 要求收到 在此处具有非空值。例如,如果我返回到隐藏筛选器表单的“简化”版本,则仅使用 指导 字段:

<form action="{% url action %}" method="get" class="left search col s6 hide-on-small-and-down" novalidate>
  <div class="input-field">
    <input id="search" placeholder="{{ placeholder }}"
        autocomplete="off" type="search" name="q"
        value="{{ search_form.q.value.strip|default:'' }}"
        data-query="{{ search_form.q.value.strip|default:'' }}">
    <label for="search" class="active"><i class="material-icons search-icon">search</i></label>
    <i data-behavior="search-clear"
        class="material-icons search-icon"
        {% if not search_form.q.value %}style="display: none;"{% endif %}>close</i>
  </div>
  <input type="hidden" name="guide" value="{{ request.GET.guide }}"/>
</form>

然后,我选择一个过滤器,并在搜索栏中输入搜索词:

然后当我在视图 get 方法,如下所示:

def get(self, request, *args, **kwargs):
    import ipdb; ipdb.set_trace()

我确实看到了 q 和 指导 都在 要求收到 :

ipdb> request.GET
<QueryDict: {'q': ['Christine'], 'guide': ['6']}>

因此,在“一般”形式中 request.GET.field_name ,我也希望 要求收到 如下所示,其他字段的列表也是空的。Django模板语言的点表示法似乎正试图对 'field_name' 什么也没找到;也许我应该编写一个自定义过滤器,如中所述 Django template how to look up a dictionary value with a variable 执行字典查找的步骤 field.name ?

2 回复 | 直到 7 年前

rtindru 7 年前

所以基本上可以归结为 未在GET请求中提交具有空字符串值的键 。这似乎在HTML中本机不受支持;你需要一些JS魔法来实现这一点。查看此线程: How to prevent submitting the HTML form's input field value if it empty

然而,一个纯粹的Django解决方案是修改过滤器dict以排除null键。我不确定您在Django中是如何过滤此内容的,但假设您已经覆盖了 get_queryset 方法您可以随时执行以下操作:

def get_queryset(self):
    qs = super(YourView, self).get_queryset()
    filters = {k, v for k, v in request.GET.items() if v != ''}  # Be as generic/specific as needed here for exclusion
    qs = qs.filter(**filters)  # Fire your filtering logic here; this is a sample
    return qs

Kurt Peek 7 年前

我最终通过写一个习惯来解决这个问题 get 如中所述的过滤器 Django template how to look up a dictionary value with a variable :

from django import template

register = template.Library()


@register.filter
def get(dictionary, key):
    return dictionary.get(key)

我更新了 _search.html 具体如下:

{% load get %}

<form action="{% url action %}" method="get" class="left search col s6 hide-on-small-and-down" novalidate>
  <div class="input-field">
    <input id="search" placeholder="{{ placeholder }}"
        autocomplete="off" type="search" name="q"
        value="{{ search_form.q.value.strip|default:'' }}"
        data-query="{{ search_form.q.value.strip|default:'' }}">
    <label for="search" class="active"><i class="material-icons search-icon">search</i></label>
    <i data-behavior="search-clear"
        class="material-icons search-icon"
        {% if not search_form.q.value %}style="display: none;"{% endif %}>close</i>
  </div>
  {% if filter_form %}
    {% for field in filter_form %}
      <input type="hidden" name="{{ field.name }}" value="{{ request.GET|get:field.name }}"/>
    {% endfor %}
  {% endif %}
</form>

现在,如果我尝试搜索筛选的结果,它将按预期工作:

请注意,这也适用于未应用的过滤器-这些过滤器具有 None 而不是空字符串-无需在表单中过滤掉它们。