Cannot hide "Save and add another" button in Django Admin

Question

I would like to hide all the "Save" buttons in Django's Admin's Change Form, for a specific model, when certain conditions are met. Therefore, I override the changeform_view method in the relevant ModelAdmin, like so:

def changeform_view(self, request, object_id=None, form_url='', extra_context=None):
    extra_context = extra_context or {}
    obj = collection_management_MammalianLine.objects.get(pk=object_id)
    if obj:
        if not (request.user.is_superuser or request.user.groups.filter(name='Lab manager').exists() or request.user == obj.created_by):
            extra_context['show_save'] = False
            extra_context['show_save_and_continue'] = False
            extra_context['show_save_and_add_another'] = False
        else:
            pass
    else:
        pass
    return super(MammalianLinePage, self).changeform_view(request, object_id, extra_context=extra_context)

With this code, I can successfully hide the "Save" and "Save and continue" buttons, but not the "Save and add another" one. I can see that submit_line.html contains the following three lines:

{% if show_save %}<input type="submit" value="{% trans 'Save' %}" class="default" name="_save" />{% endif %}
{% if show_save_and_add_another %}<input type="submit" value="{% trans 'Save and add another' %}" name="_addanother" />{% endif %}
{% if show_save_and_continue %}<input type="submit" value="{% trans 'Save and continue editing' %}" name="_continue" />{% endif %}

My question is: why can I hide the "Save" and "Save and continue" buttons, but not the "Save and add another" one? Even though the relevant templatetag (show_save_and_continue) is in the template.

Answer 1

The other keys are checked for in the passed context except show_save_and_continue. Django always sets this directly.

'show_save_and_add_another': (
        context['has_add_permission'] and not is_popup and
        (not save_as or context['add'])
    ),

You can patch the submit_row template tag function to first check the context dictionary for show_save_and_add_another.

@register.inclusion_tag('admin/submit_line.html', takes_context=True)
def submit_row(context):
    """
    Display the row of buttons for delete and save.
    """
    change = context['change']
    is_popup = context['is_popup']
    save_as = context['save_as']
    show_save = context.get('show_save', True)
    show_save_and_continue = context.get('show_save_and_continue', True)
    show_save_and_add_another = context.get('show_save_and_add_another', False)
    ctx = Context(context)
    ctx.update({
        'show_delete_link': (
            not is_popup and context['has_delete_permission'] and
            change and context.get('show_delete', True)
        ),
        'show_save_as_new': not is_popup and change and save_as,
        'show_save_and_add_another': (
            context.get('show_save_and_add_another', None) or
            (context['has_add_permission'] and not is_popup and
            (not save_as or context['add']))
        ),
        'show_save_and_continue': not is_popup and context['has_change_permission'] and show_save_and_continue,
        'show_save': show_save,
    })
    return ctx

Edit

Steps to patch the "admin/submit_line.html" inclusion tag

1. Create a templatetags folder at the same level of models.py and views.py

2. Create __init__.py in the templatetags folder

3. Copy django/contrib/admin/templatetags/admin_modify.py to templatetags/admin_modify.py.

4. Overwrite submit_row function definition with the one above.

Note that this is applicable for Django 2.0 and below.

For recent Django versions, find a context mix that allows this expression to be False.e.g.

has_add_permission and not is_popup and
(not save_as or add) and can_save

See values for the names used in the above expression.