CODEWITHSUNDEEP
djangodjango-admincustomization
natasha
natasha

Reputation: 91

Django: Read only field

How do I allow fields to be populated by the user at the time of object creation ("add" page) and then made read-only when accessed at "change" page?

Upvotes: 9

Views: 7865

Answers (4)

warren
warren

Reputation: 476

The simplest solution I found was to override the get_readonly_fields function of ModelAdmin:

class TestAdmin(admin.ModelAdmin):    
    def get_readonly_fields(self, request, obj=None):
        '''
        Override to make certain fields readonly if this is a change request
        '''
        if obj is not None:
            return self.readonly_fields + ('title',)
        return self.readonly_fields
admin.site.register(TestModel, TestAdmin)

Object will be none for the add page, and an instance of your model for the change page. Edit: Please note this was tested on Django==1.2

Upvotes: 10

Clément
Clément

Reputation: 6748

There's two thing to address in your question.

1. Read-only form fields

Doesn't exist as is in Django, but you can implement it yourself, and this blog post can help.

2. Different form for add/change

I guess you're looking for a solution in the admin site context (otherwise, just use 2 different forms in your views).

You could eventually override add_view or change_view in your ModelAdmin and use a different form in one of the view, but I'm afraid you will end up with an awful load of duplicated code.

Another solution I can think of, is a form that will modify its fields upon instantiation, when passed an instance parameter (ie: an edit case). Assuming you have a ReadOnlyField class, that would give you something like:

class MyModelAdminForm(forms.ModelForm):
    class Meta:
        model = Stuff

    def __init__(self, *args, **kwargs):
        super(MyModelAdminForm, self).__init__(*args, **kwargs)
        if kwargs.get('instance') is not None:
            self.fields['title'] = ReadOnlyField()

In here, the field title in the model Stuff will be read-only on the change page of the admin site, but editable on the creation form.

Hope that helps.

Upvotes: 3

Luiz C.
Luiz C.

Reputation: 776

You can edit that model's save method to handle such a requirement. For example, you can check if the field already contains some value, if it does, ignore the new value.

Upvotes: 2

davidfischer
davidfischer

Reputation: 449

One option is to override or replace the change_form template for that specific model.

Upvotes: 1

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