Django模板中的分组CheckboxSelectMultiple [英] Grouped CheckboxSelectMultiple in Django template

问题描述

如何将 CheckboxSelectMultiple 生成的复选框按相关模型分组?

How can I group checkboxes produced by CheckboxSelectMultiple by a related model?

最好通过示例来证明这一点.

This is best demonstrated by example.

models.py:

class FeatureCategory(models.Model):
    name = models.CharField(max_length=30)

class Feature(models.Model):
    name = models.CharField(max_length=30)
    category = models.ForeignKey(FeatureCategory)

class Widget(models.Model):
    name = models.CharField(max_length=30)
    features = models.ManyToManyField(Feature, blank=True)

forms.py:

class WidgetForm(forms.ModelForm):
    features = forms.ModelMultipleChoiceField(
        queryset=Feature.objects.all(),
        widget=forms.CheckboxSelectMultiple,
        required=False
    )
    class Meta:
        model = Widget

views.py:

def edit_widget(request):
    form = WidgetForm()
    return render(request, 'template.html', {'form': form})

template.html:

{{ form.as_p }}

以上产生以下输出:

[] Widget 1
[] Widget 2
[] Widget 3
[] Widget 1
[] Widget 2

我希望功能复选框按功能类别分组(基于 ForeignKey):

What I would like is for the feature checkboxes to be grouped by feature category (based on the ForeignKey):

Category 1:
  [] Widget 1
  [] Widget 2
  [] Widget 3

Category 2:
  [] Widget 1
  [] Widget 2

我怎样才能做到这一点?我曾尝试使用 {% regroup %} 模板标签无济于事.

How can I achieve this? I have tried using the {% regroup %} template tag to no avail.

非常感谢任何建议.

谢谢.

推荐答案

您必须编写自定义 CheckboxSelectMultiple 小部件.使用 snippet 我尝试通过添加 CheckboxSelectMultiple 字段使 CheckboxSelectMultiple 字段可迭代code>category_name 作为字段 attrs 中的属性.这样我以后就可以在模板中使用 regroup 标签.

You have to write the custom CheckboxSelectMultiple widget. Using the snippet I have tried make the CheckboxSelectMultiple field iterable by adding the category_name as an attribute in field attrs. So that I can use regroup tag in template later on.

下面的代码是根据你的需要从片段中修改的，显然这段代码可以做得更干净、更通用，但目前它不是通用的.

The below code is modified from snippet according to your need, obviously this code can be made more cleaner and more generic, but at this moment its not generic.

forms.py

from django import forms
from django.forms import Widget
from django.forms.widgets import SubWidget
from django.forms.util import flatatt
from django.utils.html import conditional_escape
from django.utils.encoding import StrAndUnicode, force_unicode
from django.utils.safestring import mark_safe

from itertools import chain
import ast

from mysite.models import Widget as wid # your model name is conflicted with django.forms.Widget
from mysite.models import Feature

class CheckboxInput(SubWidget):
    """
    An object used by CheckboxRenderer that represents a single
    <input type='checkbox'>.
    """
    def __init__(self, name, value, attrs, choice, index):
        self.name, self.value = name, value
        self.attrs = attrs
        self.choice_value = force_unicode(choice[1])
        self.choice_label = force_unicode(choice[2])

        self.attrs.update({'cat_name': choice[0]})

        self.index = index

    def __unicode__(self):
        return self.render()

    def render(self, name=None, value=None, attrs=None, choices=()):
        name = name or self.name
        value = value or self.value
        attrs = attrs or self.attrs

        if 'id' in self.attrs:
            label_for = ' for="%s_%s"' % (self.attrs['id'], self.index)
        else:
            label_for = ''
        choice_label = conditional_escape(force_unicode(self.choice_label))
        return mark_safe(u'<label%s>%s %s</label>' % (label_for, self.tag(), choice_label))

    def is_checked(self):
        return self.choice_value in self.value

    def tag(self):
        if 'id' in self.attrs:
            self.attrs['id'] = '%s_%s' % (self.attrs['id'], self.index)
        final_attrs = dict(self.attrs, type='checkbox', name=self.name, value=self.choice_value)
        if self.is_checked():
            final_attrs['checked'] = 'checked'
        return mark_safe(u'<input%s />' % flatatt(final_attrs))

class CheckboxRenderer(StrAndUnicode):
    def __init__(self, name, value, attrs, choices):
        self.name, self.value, self.attrs = name, value, attrs
        self.choices = choices

    def __iter__(self):
        for i, choice in enumerate(self.choices):
            yield CheckboxInput(self.name, self.value, self.attrs.copy(), choice, i)

    def __getitem__(self, idx):
        choice = self.choices[idx] # Let the IndexError propogate
        return CheckboxInput(self.name, self.value, self.attrs.copy(), choice, idx)

    def __unicode__(self):
        return self.render()

    def render(self):
        """Outputs a <ul> for this set of checkbox fields."""
        return mark_safe(u'<ul>
%s
</ul>' % u'
'.join([u'<li>%s</li>'
                % force_unicode(w) for w in self]))

class CheckboxSelectMultipleIter(forms.CheckboxSelectMultiple):
    """
    Checkbox multi select field that enables iteration of each checkbox
    Similar to django.forms.widgets.RadioSelect
    """
    renderer = CheckboxRenderer

    def __init__(self, *args, **kwargs):
        # Override the default renderer if we were passed one.
        renderer = kwargs.pop('renderer', None)
        if renderer:
            self.renderer = renderer
        super(CheckboxSelectMultipleIter, self).__init__(*args, **kwargs)

    def subwidgets(self, name, value, attrs=None, choices=()):
        for widget in self.get_renderer(name, value, attrs, choices):
            yield widget

    def get_renderer(self, name, value, attrs=None, choices=()):
        """Returns an instance of the renderer."""

        choices_ = [ast.literal_eval(i[1]).iteritems() for i in self.choices]
        choices_ = [(a[1], b[1], c[1]) for a, b, c in choices_]

        if value is None: value = ''
        str_values = set([force_unicode(v) for v in value]) # Normalize to string.
        if attrs is None:
            attrs = {}
        if 'id' not in attrs:
            attrs['id'] = name
        final_attrs = self.build_attrs(attrs)
        choices = list(chain(choices_, choices))
        return self.renderer(name, str_values, final_attrs, choices)

    def render(self, name, value, attrs=None, choices=()):
        return self.get_renderer(name, value, attrs, choices).render()

    def id_for_label(self, id_):
        if id_:
            id_ += '_0'
        return id_

class WidgetForm(forms.ModelForm):
    features = forms.ModelMultipleChoiceField(
        queryset=Feature.objects.all().values('id', 'name', 'category__name'),
        widget=CheckboxSelectMultipleIter,
        required=False
    )
    class Meta:
        model = wid

然后在模板中:

{% for field in form %}
{% if field.name == 'features' %} 
    {% regroup field by attrs.cat_name as list %}

    <ul>
    {% for el in list %}
        <li>{{el.grouper}}
        <ul>
            {% for e in el.list %}
                {{e}} <br />
            {% endfor %}
        </ul>
        </li>
    {% endfor %}
    </ul>
{% else %}
    {{field.label}}: {{field}}
{% endif %}

{% endfor %}

结果:我在类别表中添加了国家/地区名称，在功能表中添加了城市名称，因此在模板中我能够根据国家/地区(类别)重新组合城市(功能)

Results: I added countries name in category table, and cities name in features table so in template I was able to regroup the cities (features) according to country (category)

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