在一个字符字段中使用两个模型字段组合的 Django ModelForm

Posted 2023-02-24

【中文标题】在一个字符字段中使用两个模型字段组合的 Django ModelForm

【英文标题】：Django ModelForm that uses a combination of two model fields in one charfield

【发布时间】：2018-11-01 00:32:33

【问题描述】：

是否可以将 ModelForm 中的两个模型字段组合到一个字符字段中？

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)

因此从模型返回样本为 / 或 123/18

但是，如果我制作一个 ModelForm，我不希望两个字段分别输入 request_number 和年份。相反，我想要一个字符域供用户输入 123/18， 我的表单来解析 request_number 和年份，并验证 ModelForm。

我已经将其作为普通的 django 表单进行了尝试，但在我看来它并没有验证。

表格：

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，并创建一个结合了两者的字段，然后可以在“clean_request_number”和 clean_year“方法中对其进行解析和验证？或者为什么我在这个自定义表单中出错了？

谢谢

【问题讨论】：

似乎您需要自定义小部件。 ***.com/questions/4707192/…

【参考方案1】：

以下代码在我的机器上运行，即 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:]"

forms.py

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+/\d2,4$', "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()

结果/sample_create.html

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

结果/sample_detail.html

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