[Django]ModelFormのバリデーション – ソフトウェアエンジニアの技術ブログ：Software engineer tech blog

– バリデーションはsaveの時に実行されるので、モデルの更新時にはモデル側でバリデーションをかける

/hello/forms.py

class FriendForm(forms.ModelForm):
	class Meta:
		model = Friend
		fields = ['name','mail','gender','age','birthday']

/hello/models.py

class Friend(models.Model):
	name = models.CharField(max_length=100)
	mail = models.EmailField(max_length=200)
	gender = models.BooleanField()
	age = models.IntegerField(default=0)
	birthday = models.DateField()

– save以外に自分でチェックをかけることも可能
/hello/views.py

def check(request):
	params = {
		'title': 'Hello',
		'message': 'check validation.',
		'form': FriendForm(),
	}
	if(request.method == 'POST'):
		obj = Friend()
		form = FriendForm(request.POST, instance=obj)
		params['form'] = form
		if(form.is_valid()):
			params['message'] = 'OK!'
		else:
			params['message'] = 'no good.'
	return render(request, 'hello/check.html', params)

/hello/templates/hello/check.html

<body class="container">
	<h1 class="display-4 text-primary">{{title}}</h1>
	<p>{{message|safe}}</p>
	<form action="{% url 'check' %}" method="post">
		{% csrf_token %}
		<table class="table">
		{{ form.as_table }}
		<tr><th></th><td>
		<input type="submit" value="click" class="btn btn-primary mt-2">
		</td></tr>
		</table>
	</form>
</body>

– forms.FormとModelFormのバリデーションは異なる

### モデルにバリデーションの組み込み
/hello/models.py

from django.db import models
from django.core.validators import MinValueValidator, MaxValueValidator

class Friend(models.Model):
	name = models.CharField(max_length=100)
	mail = models.EmailField(max_length=200)
	gender = models.BooleanField()
	age = models.IntegerField(validators=[MinValueValidator(0), MaxValueValidator(150)])
	birthday = models.DateField()

### モデルで使えるバリデータ
– MinValueValidator/MaxValueValidator, MinLengthValidator/MaxLengthValidator

from django.db import models
from django.core.validators import MinLengthValidator

class Friend(models.Model):
	name = models.CharField(max_length=100, validators=[MinLengthValidator(10)])
	mail = models.EmailField(max_length=200, validators=[MinLengthValidator(10)])
	gender = models.BooleanField()
	age = models.IntegerField()
	birthday = models.DateField()

– EmailValidator/URLValidator
– ProhibitNullCharactersValidator
– RegexValidator

from django.core.validators import RegexValidator

class Friend(models.Model):
	name = models.CharField(max_length=100, validators=[RegexValidator(r'^[a-z]*$')])

バリデーション定義によってmodelに組み込んでいくイメージです。