使用 Django 1.6 从 2 个模型构建表单的最佳方法是什么

Question

对于一个小应用程序，我定义了两个模型：

class Pressure (models.Model):
    user = models.ForeignKey(User)
    sys = models.FloatField(blank=False, null=False, verbose_name=_(u"systolic"))
    dia = models.FloatField(blank=False, null=False, verbose_name=_(u"diastolic"))
    pulse = models.IntegerField(blank=False, null=False, verbose_name=_(u"Pulse"))
    timestamp = models.DateTimeField(verbose_name=_(u"Messurement timestamp"))

    def __unicode__(self):
        return self.timestamp.strftime("%y-%m-%d: %H-%M")

class Weight(models.Model):
    user = models.ForeignKey(User)
    weight = models.FloatField(blank=False, null=False, verbose_name=_(u"Weight"))
    timestamp = models.DateTimeField(verbose_name=_(u"Messurement timestamp"))

    def __unicode__(self):
        return self.timestamp.strftime("%y-%m-%d: %H-%M")

不，我想为这两个模型构建一个合并表单，其中用户和时间戳对于两个模型都是相同的。其余文件应该是可选的。这意味着，如果没有给出例如重量，不得插入数据库等。

我正在阅读有关 mixins 和一些表单集的信息，但不知道这里最好的方法是什么。

Answer 1

您不需要一个表单来处理这个问题。您只需要一个处理两个模型的表单的视图。基本思想很简单：创建两个表单类，并在同一个<form> 元素中呈现给用户。提交时，检查两个表单是否有效，然后将它们都保存并将用户发送到下一页。它看起来像这样：

from django import forms
from django.contrib.auth.decorators import login_required
from django.shortcuts import render, redirect
from django.utils.timezone import now

from .models import Pressure, Weight


class PressureForm(forms.ModelForm):

    class Meta:
        model = Pressure
        exclude = ('user', 'timestamp', )


class WeightForm(forms.ModelForm):

    class Meta:
        model = Weight
        exclude = ('user', 'timestamp', )


@login_required
def submit(request):
    if request.method == 'POST'
        pressure_form = PressureForm(request.POST)
        weight_form = WeightForm(request.POST)
        if all(form.is_valid() for form in [pressure_form, weight_form]):
            record_time = now()
            pressure = pressure_form.save(commit=False)
            pressure.timestamp = record_time
            pressure.user = request.user
            pressure.save()
            weight = weight_form.save(commit=False)
            weight.timestamp = record_time
            weight.user = request.user
            weight.save()
            return redirect('<insert-name-of-success-url>')
    else:
        pressure_form = PressureForm()
        weight_form = WeightForm()
    context = {
        'pressure_form': pressure_form,
        'weight_form': weight_form,
    }
    return render(request, '<insert-template-name>', context)

您不需要表单集或通用视图来处理此问题。这是一个简单而直接的观点。如果您发现自己经常重复这种模式，那么您可能会考虑创建一些视图类来处理这种情况。没有一个内置的泛型会为您执行此操作。

Answer 2

您可以为 2 个模型创建 2 个 ModelFrom。在您的一种形式中，排除“用户”和“时间戳”字段。在模板中，将两种形式的字段放在一个 <form> 标记中。鉴于您应该首先使用“用户”和“时间戳”保存表单，然后将数据从其中放入使用第二种表单创建的实例：

class PressureForm(forms.ModelForm):
    class Meta:
        model = Pressure

class WeightForm(forms.ModelForm):
    class Meta:
        model = Weight
        exclude = ('user', 'timestamp')

def someview(request):
    if request.method == 'POST':
        pressure_form = PressureForm(request.POST) # user and timestamp is here
        weight_form = WeightForm(request.POST)

        if pressure_form.is_valid():
            pressure = pressure_form.save()

            if weight_form.is_valid():
                weight = weight_form.save(commit=False)
                weight.user = pressure.user
                weight.timestamp = pressure.timestamp
                weight.save()