Django窗体、窗体字段的继承和顺序

自Django 1.9+

Django 1.9添加了一个新的 Form 属性, field_order ,允许对字段排序,而不管它们在类中的声明顺序如何。

class MyForm(forms.Form):
    summary = forms.CharField()
    description = forms.CharField(widget=forms.TextArea)
    author = forms.CharField()
    notes = form.CharField()

    field_order = ['author', 'summary']

中缺少字段 场序 在类中保持它们的顺序,并在列表中指定的顺序之后追加。上面的示例将按以下顺序生成字段: ['author', 'summary', 'description', 'notes']

请参阅文档: https://docs.djangoproject.com/en/stable/ref/forms/api/#notes-on-field-ordering

至Django 1.6

我也遇到了同样的问题,我发现了另一种在 Django CookBook :

class EditForm(forms.Form):
    summary = forms.CharField()
    description = forms.CharField(widget=forms.TextArea)


class CreateForm(EditForm):
    name = forms.CharField()

    def __init__(self, *args, **kwargs):
        super(CreateForm, self).__init__(*args, **kwargs)
        self.fields.keyOrder = ['name', 'summary', 'description']

从Django 1.9: https://docs.djangoproject.com/en/1.10/ref/forms/api/#notes-on-field-ordering

原始答案: django 1.9默认情况下将在表单上支持此功能 field_order :

class MyForm(forms.Form):
    ...
    field_order = ['field_1', 'field_2']
    ...

https://github.com/django/django/commit/28986da4ca167ae257abcaf7caea230eca2bcd80

我使用了Selene发布的解决方案,但发现它删除了所有未分配给keyorder的字段。我要子类化的表单有很多字段,所以这对我来说不是很好。我用Akaihola的答案编写了这个函数来解决这个问题,但是如果你想让它像Selene那样工作,你需要做的就是设置 throw_away 到 True .

def order_fields(form, field_list, throw_away=False):
    """
    Accepts a form and a list of dictionary keys which map to the
    form's fields. After running the form's fields list will begin
    with the fields in field_list. If throw_away is set to true only
    the fields in the field_list will remain in the form.

    example use:
    field_list = ['first_name', 'last_name']
    order_fields(self, field_list)
    """
    if throw_away:
        form.fields.keyOrder = field_list
    else:
        for field in field_list[::-1]:
            form.fields.insert(0, field, form.fields.pop(field))

这就是我在自己的代码中使用它的方式:

class NestableCommentForm(ExtendedCommentSecurityForm):
    # TODO: Have min and max length be determined through settings.
    comment = forms.CharField(widget=forms.Textarea, max_length=100)
    parent_id = forms.IntegerField(widget=forms.HiddenInput, required=False)

    def __init__(self, *args, **kwargs):
        super(NestableCommentForm, self).__init__(*args, **kwargs)
        order_fields(self, ['comment', 'captcha'])

似乎在某一点上,字段顺序的底层结构从特定于Django的 SordedDict 以python标准 OrderedDict

因此,在1.7中,我必须做以下工作:

from collections import OrderedDict

class MyForm(forms.Form):

    def __init__(self, *args, **kwargs):
        super(MyForm, self).__init__(*args, **kwargs)
        original_fields = self.fields
        new_order = OrderedDict()
        for key in ['first', 'second', ... 'last']:
            new_order[key] = original_fields[key]
        self.fields = new_order

我相信有人可以把它打成两到三条线,但为了S.O.的目的,我认为清楚地展示它的工作原理比劈刀更好。

您还可以创建一个装饰器来订购字段(受Joshua解决方案的启发):

def order_fields(*field_list):
    def decorator(form):
        original_init = form.__init__
        def init(self, *args, **kwargs):
            original_init(self, *args, **kwargs)        
            for field in field_list[::-1]:
                self.fields.insert(0, field, self.fields.pop(field))
        form.__init__ = init
        return form            
    return decorator

这将确保传递给装饰器的所有字段都位于第一位。 您可以这样使用它:

@order_fields('name')
class CreateForm(EditForm):
    name = forms.CharField()

接受答案的方法使用了Django 1.7中更改的内部Django Forms API。 The project team's opinion is that it should never have been used in the first place. 现在,我使用此函数对表单重新排序。此代码使用 OrderedDict :

def reorder_fields(fields, order):
    """Reorder form fields by order, removing items not in order.

    >>> reorder_fields(
    ...     OrderedDict([('a', 1), ('b', 2), ('c', 3)]),
    ...     ['b', 'c', 'a'])
    OrderedDict([('b', 2), ('c', 3), ('a', 1)])
    """
    for key, v in fields.items():
        if key not in order:
            del fields[key]

    return OrderedDict(sorted(fields.items(), key=lambda k: order.index(k[0])))

我在这类课程中用到:

class ChangeOpenQuestion(ChangeMultipleChoice):

    def __init__(self, *args, **kwargs):
        super(ChangeOpenQuestion, self).__init__(*args, **kwargs)
        key_order = ['title',
                     'question',
                     'answer',
                     'correct_answer',
                     'incorrect_answer']

        self.fields = reorder_fields(self.fields, key_order)

请参阅中的注释 this SO question 在Django的内部结构跟踪字段顺序的过程中,答案包括如何根据您的喜好“重新排序”字段的建议(最终归结为与 .fields 属性)。

更改字段顺序的其他方法:

弹出式和插入式:

self.fields.insert(0, 'name', self.fields.pop('name'))

流行和追加:

self.fields['summary'] = self.fields.pop('summary')
self.fields['description'] = self.fields.pop('description')

全部弹出并追加:

for key in ('name', 'summary', 'description'):
    self.fields[key] = self.fields.pop(key)

有序副本:

self.fields = SortedDict( [ (key, self.fields[key])
                            for key in ('name', 'summary' ,'description') ] )

但塞莱恩在《姜戈食谱》中的做法仍然让人感觉最清楚。

基于@akaihola的回答,并更新为与最新的django 1.5合作 self.fields.insert 正在被 depreciated .

from easycontactus.forms import *
from django import forms
class  CustomEasyContactUsForm(EasyContactUsForm):
    ### form settings and configuration
    CAPTHCA_PHRASE = 'igolf'

    ### native methods
    def __init__(self, *args, **kwargs):
        super(CustomEasyContactUsForm, self).__init__(*args, **kwargs)
        # re-order placement of added attachment field 
        self.fields.keyOrder.insert(self.fields.keyOrder.index('captcha'),
                                    self.fields.keyOrder.pop(self.fields.keyOrder.index('attachment'))
                                    )

    ### field defintitions
    attachment = forms.FileField()

在上面,我们正在扩展easycontactusForm基类,正如在中定义的那样。 django-easycontactus 包裹。

我构建了一个从django registration redux的“registration form”继承的表单“exregistrationform”。我面临两个问题,其中一个是在创建新表单后重新排序HTML输出页上的字段。

我解决了如下问题:

1。问题1:从注册表中删除用户名:在my_app.forms.py中

    class ExRegistrationForm(RegistrationForm):
          #Below 2 lines extend the RegistrationForm with 2 new fields firstname & lastname
          first_name = forms.CharField(label=(u'First Name'))
          last_name = forms.CharField(label=(u'Last Name'))

          #Below 3 lines removes the username from the fields shown in the output of the this form
          def __init__(self, *args, **kwargs):
          super(ExRegistrationForm, self).__init__(*args, **kwargs)
          self.fields.pop('username')

2。问题2:使firstname和firstname出现在最上面:在templates/registration/registration.html中

可以按所需的顺序单独显示字段。如果字段的数量较少,这将有所帮助,但如果您有大量字段,而实际上不可能在表单中实际写入它们,则情况并非如此。

     {% extends "base.html" %}
     {% load i18n %}

     {% block content %}
     <form method="post" action=".">
          {% csrf_token %}

          #The Default html is: {{ form.as_p }} , which can be broken down into individual elements as below for re-ordering.
          <p>First Name: {{ form.first_name }}</p>
          <p>Last Name:  {{ form.last_name }}</p>
          <p>Email: {{ form.email }}</p>
          <p>Password: {{ form.password1 }}</p>
          <p>Confirm Password: {{ form.password2 }}</p>

          <input type="submit" value="{% trans 'Submit' %}" />
      </form>
      {% endblock %}