TypedChoiceField — Django Forms

Python Methods and Functions

TypedChoiceField has one additional required argument:

  • choice:
    Or 2-tuple iteration to use as a selection for this field, or a callable function that returns such an iteration. This argument takes the same formats as the select argument for the model field.

TypedChoiceField has two optional arguments:

  • Force:
    A function that takes one argument and returns a coerced value. Examples include the built-in type int, float, bool, and others. The default is the identity function.
  • empty_value:
    The value used to represent empty. The default is an empty string; There is no other common choice here.

Syntax

 field_name = forms.TypedChoiceField ( * * options ) 

Django form TypedChoiceField Explanation

Illustration of a TypedChoiceField using an example. Consider a project named pythonengineering that has an application named geeks .

Refer to the following articles to check how to create a project and an app in Django.

Enter the following code into the forms.py file of the geeks application.

from django import forms

 
# repeat

GEEKS_CHOICES = (

  ( 1 , "A" ),

( 2 , "B" ),

( 3 , "C" ),

( 4 , "D" ),

( 5 , " E " ),

)

 
# create a form

class GeeksForm (forms.Form):

geeks_field = forms.TypedChoiceField (

choices = GEEKS_CHOICES,

coerce = str

)

Add the geek app to 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' ,

]

Now, in order to convert this form to a view, we need a view and a URL associated with this URL. Let's first create a view in the views.py of the geeks app,

from django .shortcuts import render

from . forms import GeeksForm

 
# Create your views here.

def home_view (request):

context = {}

  context [ 'form' ] = GeeksForm ()

return render (request, "home.html" , context)

Here we import this particular form from forms.py and instantiate it in the view so that it could be displayed in the template. 
Now, to initiate your Django form, you need to create a home.html where you can create things as you see fit. Let's create a form in home.html .

& lt; form method = "GET" & gt; 

{{form}}

& lt; input type = "submit" value = "Submit" & gt; 

& lt; / form & gt; 

Finally, the URL to map to this view in urls.py

from django.urls import path

 
# import views from views..py

from . views import home_view

 

urlpatterns = [

  path ('', home_view),

]

Let's start the server and check what's on actually happened, Run

 Python manage.py runserver 

Thus, the geeks_field TypedChoiceField is created by replacing "_" with "". This is a field for entering row selection.




How to use the TypedChoiceField?

TypedChoiceField is used to enter small strings into the database. You can enter state, country, city, and so on. So far, we've discussed how to implement a TypedChoiceField, but how to use it in a view to execute the boolean part. To do some logic, we need to get the value entered in the field into a Python string instance. 
In views.py,

from django.shortcuts import render

from .forms import GeeksForm

 
# Create your views here.

def home_view (request):

  context = {}

  form = GeeksForm (request.GET or None )

  context [ 'form' ] = form

if request.GET and form.is_valid ():

  temp = form.cleaned_data.get ( " geeks_field " )

print ( type (temp))

return render (request, " home.html " , context)

Now let's try to enter data in the field.

Now this data can be obtained using the appropriate query dictionary. If the method is GET, the data will be available in request.GET, and if post, then request.POST , respectively. we used the form's cleaned_data attribute to fetch data from the view. In the above example, we have a value in temp that we can use for any purpose.

It exposes the variable int 2 as a string class, since the value is quoted by the TypedChoiceField. This is the advantage of ChoiceField over TypedChoiceField.

Main Field Arguments

Main Field Arguments — they are arguments given to each field to apply some kind of constraint or to convey a particular characteristic to a particular field. For example, adding the required = False argument to the TypedChoiceField will allow the user to leave it blank. Each Field constructor takes at least these arguments. Some Field classes accept additional field-specific arguments, but you should always accept the following:

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.





Tutorials