How to make auto-genertion(auto-fill and increment) in django admin-CodePudding

I want to make code field should be auto filled and auto increment in django admin. models.py

class GeneralDocumentType(models.Model):
    code = models.CharField(max_length=10, null=False, unique=True)
    name = models.CharField(max_length=100, null=False, unique=True)
    description = models.TextField(blank=True, null=True)

    def __str__(self):
        return self.name

I want to show my code field default=DOC001, and it will show increment by 1 before adding data by user.How can I achieve this?..

CodePudding user response：

Django ModelAdmin has support for get_changeform_initial_data. In your admin you can override this method to get value based on the latest id info. For example:

class YourModelAdmin(admin.ModelAdmin):
  ...
  def get_changeform_initial_data(self, request):
    # getting the latest id
    try:
        latest_document_type = GeneralDocumentType.object.latest('id')
        latest_id = latest_document_type.id   1
    except GeneralDocumentType.DoesNotExist:
        # incase there no object yet
        latest_id = 0
        
    return {'code': f'DOC{latest_id}'}

Note: this only work for adding new object, ModelAdmin. Doesn't work for InlineModelAdmin