How to set initial value for read only field

问题

I have a django application which is using django.contrib.admin for administrative tasks.

For one model I now need to add a field which indicates which part of the code each row was created from. I am using readonly_fields to prevent this value from being changed through the administration interface.

A default value in this field will tell me that the row was either

created before the field was introduced
created by code which has not been updated to set the field
created through the administration interface

But I need better granularity than that. In particular I want to be able to distinguish between a row created by code which doesn't know about the field, and a row created through the administration interface.

Is there some way my ModelAdmin class can specify an initial value for a field mentioned in readonly_fields?

回答1:

One way to do this is,

def get_form(self, request, caja=None, **kwargs):
    self.form = YourModelForm

    form = super(YourModelAdmin, self).get_form(request, caja, **kwargs)
    form.base_fields['field'].initial = your_initial_data
    return form

回答2:

I found this solution, which appears to work:

class Admin(ModelAdmin):
    readonly_fields = ('created_by',)
    def save_form(self, request, form, change):
        r = super(Admin, self).save_form(request, form, change)
        if not change:
            assert r.created_by == CREATED_BY_UNKNOWN
            r.created_by = CREATED_BY_ADMIN
        return r

CREATED_BY_UNKNOWN and CREATED_BY_ADMIN are values defined elsewhere in my code.

来源：https://stackoverflow.com/questions/32796938/how-to-set-initial-value-for-read-only-field

标签

django-1.6