error_messages — inline field validation in Django

For example, you can override the "This field is required" message for your own message. This allows you to override the default messages that appear in the field. Pass in a dictionary with keys matching the error messages you want to override. Error message keys include null , blank , invalid , invalid_choice , unique and unique_for_date .

Syntax —

 field_name = models.Field (error_messages = {"key": "message"}) 

Editing an inline field in Django editable = False explanation

error_messages illustration 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.

• How to Create a Basic Project using MVT in Django?
• How to Create an App in Django?

Enter the following code into the models.py file of the geeks application. We’ll use CharField to experiment with all the margin variations.

from django.db import models from django.db.models import Model # Create your models here.    class GeeksModel (Model): geeks_field = models.CharField ( max_length = 200 ,    unique = True )

After running makemigrations and migrating to Django and rendering of the above model, let’s create an instance from the Django admin with the string " a ". Now, to break the unique = True constraint, let’s try to create another instance of the model using the same string. It will now show this error.

Now let’s change this error message to “ The Geeks field you specified is not unique ”using error_messages . Change models.py to

from django.db import models from django.db.models import Model # Create your models here.   class GeeksModel (Model): geeks_field = models.CharField ( max_length = 200 ,    unique = True , error_messages = { "unique" : "The Geeks Field you enetered is not unique." } )

Since models.py is modified, run makemigrations and transfer the project again. Open the admin interface and try to create the instance again using the "a" line. 

You may see the modified error message. Therefore, error_messages changes the error message fields. You can change using other attributes such as zero , empty , etc.