Don't show buttons to add/change/delete a ForeignKey element of a model in form (tested in admin form)

NoEditForeignTablesInlineMixin.py

class NoEditForeignTablesInlineMixin(object):
    """ Don't show links to add/edit/delete foreign key element besides ForeignKey selection in forms """
    no_edit_foreign_tables_in_form = []

    def get_form(self, request, obj=None, **kwargs):
        """
        Don't allow adding/changing/deleting users inline
        """
        form = super(NoEditForeignTablesInlineMixin, self).get_form(request, obj, **kwargs)
        for key in self.no_edit_foreign_tables_in_form:
            form.base_fields[key].widget.can_add_related = False
            form.base_fields[key].widget.can_change_related = False
            form.base_fields[key].widget.can_delete_related = False
        return form


# Example
class PurchaseAdmin(NoEditForeignTablesInlineMixin, admin.ModelAdmin):
    no_edit_foreign_tables_in_form = ["user"]