Built-in Form Field Validations in Django Forms are the default validations that come predefined to all fields. Every field comes in with some built-in validations from Django validators. Each Field class constructor takes some fixed arguments.
The Django Form Field Validation
Illustration of help_text using an Example. Consider a project named
Python3
Add the geeks app to
Python3
Now to render this form into a view we need a view and a URL mapped to that view. Let's create a view first in
Python3 1==
Here we are importing that particular form from forms.py and creating an object of it in the view so that it can be rendered in a template.
Now, to initiate a Django form you need to create home.html where one would be designing the stuff as they like. Let's create a form in
html
Finally, a URL to map to this view in urls.py
Python3 1==
help_text argument lets you specify descriptive text for this Field. If you provide help_text, it will be displayed next to the Field when the Field is rendered by one of the convenience Form methods. The default help_text for a Field is empty. Let's check how to use help_text in a field using a project.
Syntax
field_name = models.Field(option = value)
Django Form Field Validation help_text Explanation
Illustration of help_text using an Example. Consider a project named geeksforgeeks having an app named geeks.
Refer to the following articles to check how to create a project and an app in Django.Enter the following code into
forms.py file of geeks app. We will be using CharField for experimenting for all field options.
from django import forms
class GeeksForm(forms.Form):
geeks_field = forms.CharField(help_text = "Enter your Name")
INSTALLED_APPS
# Application definition
INSTALLED_APPS = [
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'geeks',
]
views.py of geeks app,
from django.shortcuts import render
from .forms import GeeksForm
# Create your views here.
def home_view(request):
context = {}
form = GeeksForm(request.POST or None)
context['form'] = form
if request.POST:
if form.is_valid():
temp = form.cleaned_data.get("geeks_field")
print(temp)
return render(request, "home.html", context)
home.html.
<form method = "POST">
{% csrf_token %}
{{ form }}
<input type = "submit" value = "Submit">
</form>
from django.urls import path
# importing views from views..py
from .views import home_view
URLpatterns = [
path('', home_view ),
]
Let's run the server and check what has actually happened, Run
Thus, an
Python manage.py runserver
Thus, an geeks_field CharField is created with help_text "Enter your Name".
More Built-in Form Validations
| Field Options | Description |
|---|---|
| required | By default, each Field class assumes the value is required, so to make it not required you need to set required=False |
| label | The label argument lets you specify the “human-friendly” label for this field. This is used when the Field is displayed in a Form. |
| label_suffix | The label_suffix argument lets you override the form’s label_suffix on a per-field basis. |
| widget | The widget argument lets you specify a Widget class to use when rendering this Field. See Widgets for more information. |
| help_text | The help_text argument lets you specify descriptive text for this Field. If you provide help_text, it will be displayed next to the Field when the Field is rendered by one of the convenience Form methods. |
| error_messages | The error_messages argument lets you override the default messages that the field will raise. Pass in a dictionary with keys matching the error messages you want to override. |
| validators | The validators argument lets you provide a list of validation functions for this field. |
| localize | The localize argument enables the localization of form data input, as well as the rendered output. |
| disabled. | The disabled boolean argument, when set to True, disables a form field using the disabled HTML attribute so that it won’t be editable by users. |