Django ModelForm，在一个charfield中使用两个模型字段的组合

Question

是否可以在ModelForm中组合两个模型字段以在一个charfield中输入？

我的模特：

class Sample(models.Model):
    request_number = models.PositiveIntegerField()
    year = models.PositiveIntegerField()
    part = models.CharField(max_length=6, null=True, blank=True)

    class Meta:
        db_table = "sample"
        unique_together = (('request_number', 'year', 'part'),)

    def __str__(self):
        sample_id = "%s/%s" %(str(self.request_number), str(self.year)[2:])
        return(sample_id)

因此，从模型返回的样本为/或123/18

但是，如果我制作一个ModelForm，我不希望两个字段输入request_number，然后输入year。 相反，我希望一个字符字段供用户输入123/18，我的表单来解析request_number和year，并让ModelForm得以验证。

我已经尝试过将其作为普通的django表单，但是在我看来，它没有得到验证。

形成：

class SingleSampleForm(forms.Form):

    sample_id = forms.CharField(
        required=True,
        label='Sample ID:')

    class Meta:
        fields = ['sample_id']

    def __init__(self, *args, **kwargs):
        super(SingleSampleForm, self).__init__()
        self.helper = FormHelper()
        self.helper.layout = Layout(
            Field('sample_id',
                css_class="search-form-label",
                ),
            Submit('submit', 'Search sample', css_class='upload-btn')
        )

        self.helper.form_method = 'POST'

    def clean(self):
        sample_id = self.cleaned_data['sample_id']
        if sample_id:
            return sample_id
        raise ValidationError('This field is required')

views.py：

class SampleView(View):

    sample_form = SingleSampleForm

    def get(self, request, *args, **kwargs):

        sample_form = self.sample_form()
        self.context = {'sample_form': sample_form,}

        return render(request,
                'results/single_sample_search.html',
                self.context)

    def post(self, request, *args, **kwargs):
        sample_form = self.sample_form(request.POST)

        if sample_form.is_valid():
            print('Valid')
        else:
            print('not valid')

        self.context = {'sample_form': sample_form,}

        return render(request,
                'results/single_sample_search.html',
                self.context)

是否可以使用django ModelForm创建一个将两者结合起来的字段，然后可以在“ clean_request_number”和clean_year”方法中对其进行解析和验证？

谢谢

Answer 1

以下代码在我的机器上正常工作：ubuntu18.04 + python3.6.5 + django2.0 + pipenv：

models.py

from django.db import models
from django.urls import reverse


class Sample(models.Model):
    request_number = models.PositiveIntegerField()
    year = models.CharField(max_length=4, blank=True)
    part = models.CharField(max_length=6, null=True, blank=True)

    class Meta:
        db_table = "sample"
        unique_together = (("request_number", "year", "part"),)

    def get_absolute_url(self):
        return reverse("sample-detail", args=[self.pk])

    def __str__(self):
        return f"{self.request_number}/{self.year[-2:]}"

表格

from django import forms
from django.core.validators import RegexValidator
from .models import Sample


class SingleSampleForm(forms.Form):
    sample_str = forms.CharField(
        required=True, label="Sample(request_number/year):",
        validators=[
            RegexValidator(r'^\d+/\d{2,4}$', "Sample should be as `123/18`")
        ]
    )

    class Meta:
        model = Sample

views.py

from django.shortcuts import render
from django.views.generic.detail import DetailView
from django.views.generic.edit import FormView
from .forms import SingleSampleForm


class SampleCreateView(FormView):
    template_name = "results/sample_create.html"
    form_class = SingleSampleForm

    def get_success_url(self):
        return self.object.get_absolute_url()

    def form_valid(self, form):
        request_number, year = form.cleaned_data['sample_str'].split("/")
        if len(year) == 2:
            year = "20" + year
        self.object = form.Meta.model.objects.create(
            request_number=request_number, year=year
        )
        return super().form_valid(form)


class SampleDetailView(DetailView):
    template_name = "results/sample_detail.html"
    queryset = SingleSampleForm.Meta.model.objects.all()

results / sample_create.html

<form method="post">{% csrf_token %}
    {{ form }}
    <input type="submit" value="OK">
</form>

results / sample_detail.html

<p>request number: {{ object.request_number }}</p>
<p>year: {{ object.year }}</p>