Django表单根据另一个字段更改必填字段

Question

我有一个 django 表单 InstellingenForm，它有几个输入字段。都应该是必需的。但是根据“spelmodus”的输入，“tijd”或“wooden”应该变成 required=False。 （如果在“spelmodus”中选择了“tijd”，则“wooden”形式应更改为 required=False，反之亦然）我尝试使用 clean() 函数执行此操作，但我似乎无法弄清楚如何正是这样做。

forms.py：

from django import forms

SPELMODUS = [
    ("", ""),
    ('tijd', 'Tijd'),
    ('woorden', 'Woorden'),
]

TIJD = [
    ("", ""),
    ('een', '1 minuut'),
    ('twee', '2 minuten'),
    ('vijf', '5 minuten'),
]

WOORDEN = [
    ("", ""),
    ('vijftig', '50 woorden'),
    ('honderd', '100 woorden'),
    ('honderdvijftig', '150 woorden'),
]

TALEN = [
    ("", ""),
    ('nederlands', 'Nederlands'),
    ('engels', 'Engels'),
]

MOEILIJKHEID = [
    ("", ""),
    ('makkelijk', 'Makkelijk'),
    ('gemiddeld', 'Gemiddeld'),
    ('moeilijk', 'Moeilijk'),
]


class InstellingenForm(forms.Form):
    naam = forms.CharField(label="Naam", max_length=10, required=True, widget=forms.TextInput(attrs={'class': 'input-container'}))
    spelmodus = forms.ChoiceField(label="Spelmodus", choices=SPELMODUS, required=True, widget=forms.Select(attrs={'class': 'input-container', 'id': 'spelmodus', 'onchange': 'hideShow(this.value)', }))
    tijd = forms.ChoiceField(label="", choices=TIJD, widget=forms.Select(attrs={'class': 'input-container', 'id': 'tijdClass'}))
    woorden = forms.ChoiceField(label="", choices=WOORDEN, widget=forms.Select(attrs={'class': 'input-container', 'id': 'woordenClass'}))
    taal = forms.ChoiceField(label="Taal", choices=TALEN, required=True, widget=forms.Select(attrs={'class': 'input-container'}))
    moeilijkheid = forms.ChoiceField(label="Moeilijkheid", choices=MOEILIJKHEID, required=True, widget=forms.Select(attrs={'class': 'input-container'}))

    def clean(self):
        if self.data.get('spelmodus', 'tijd'):
            self.fields['woorden'].required = False
        elif self.data.get('spelmodus', 'woorden'):
            self.fields['tijd'].required = False
        super(InstellingenForm, self)._clean_fields()

views.py：

def instellingenDatabase(request):
    if request.method == "POST":
        form = InstellingenForm(request.POST)
        if form.is_valid():
            return HttpResponseRedirect('/')
    rendered = render(request, 'instellingenDatabase.html', {
        'formulier': form
    })
    return HttpResponse(rendered)

instellingenDatabase.html：

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>Title</title>
    {% load static %}
    <link rel="stylesheet" type="text/css" href="{% static 'instellingen.css' %}">
    <script type='text/javascript' src="{% static 'instellingen.js' %}"></script>
</head>

<body>
    {% include "header.html" %}
    <div class="bodypage">
        <div class="settings-container">
            <div class="playText">
                Play
            </div>
            <form method="post">
                {% csrf_token %}
                <table>
                {% for field in formulier %}
                    {{ field.label }}
                    {{ field }}
                {% endfor %}
                </table>
                <br>
                <button type="submit" name="Start" value="Start" class="button">Start</button>
            </form>
        </div>
    </div>

</body>

</html>

Answer 1

您的方法不起作用，因为在调用 clean 之前，这些字段已经被清理了。您应该覆盖__init__，而不是针对您可能想要对表单进行的这些类型的更改。：

class InstellingenForm(forms.Form):
    naam = forms.CharField(label="Naam", max_length=10, required=True, widget=forms.TextInput(attrs={'class': 'input-container'}))
    spelmodus = forms.ChoiceField(label="Spelmodus", choices=SPELMODUS, required=True, widget=forms.Select(attrs={'class': 'input-container', 'id': 'spelmodus', 'onchange': 'hideShow(this.value)', }))
    tijd = forms.ChoiceField(label="", choices=TIJD, widget=forms.Select(attrs={'class': 'input-container', 'id': 'tijdClass'}))
    woorden = forms.ChoiceField(label="", choices=WOORDEN, widget=forms.Select(attrs={'class': 'input-container', 'id': 'woordenClass'}))
    taal = forms.ChoiceField(label="Taal", choices=TALEN, required=True, widget=forms.Select(attrs={'class': 'input-container'}))
    moeilijkheid = forms.ChoiceField(label="Moeilijkheid", choices=MOEILIJKHEID, required=True, widget=forms.Select(attrs={'class': 'input-container'}))

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        if 'spelmodus' in self.data:
            spelmodus = self.data.get('spelmodus')
            if spelmodus == 'tijd':
                self.fields['woorden'].required = False
            elif spelmodus == 'woorden':
                self.fields['tijd'].required = False

此外，您从未在视图中使用过该表单。您只需将它传递给上下文并渲染它。如果要检查表单是否有效，则需要使用is_valid 方法。您已在编辑中添加了该内容，但现在您从未在 GET 请求的情况下制作表单，您也需要这样做：

def instellingenDatabase(request):
    if request.method == "POST":
        form = InstellingenForm(request.POST)
        if form.is_valid():
            print(form.cleaned_data.get('spelmodus')) # Check value of spelmodus
            return HttpResponseRedirect('/')
        print(form.errors) # print errors here in case form is invalid
    else:
        form = InstellingenForm() # instantiate form in case of GET request
    rendered = render(request, 'instellingenDatabase.html', {
        'formulier': form
    })
    return HttpResponse(rendered)

此外，当您手动呈现表单时，最好也呈现错误，这样用户就可以知道出了什么问题：

{% for field in formulier %}
    {{ field.label }}
    {{ field }}
    {{ field.errors }}
{% endfor %}
{{ formulier.non_field_errors }}