Disable link to edit object in django's admin (display list only)?


Question

In Django's admin, I want disable the links provided on the "select item to change" page so that users cannot go anywhere to edit the item. (I am going to limit what the users can do with this list to a set of drop down actions - no actual editing of fields).

I see that Django has the ability to choose which fields display the link, however, I can't see how I can have none of them.

class HitAdmin(admin.ModelAdmin):
    list_display = ('user','ip','user_agent','hitcount')
    search_fields = ('ip','user_agent')
    date_hierarchy = 'created'
    list_display_links = [] # doesn't work, goes to default

Any ideas how to get my object list without any links to edit?

1
39
10/24/2009 6:42:22 PM

Accepted Answer

I wanted a Log viewer as a list only.

I got it working like this:

class LogEntryAdmin(ModelAdmin):
    actions = None
    list_display = (
        'action_time', 'user',
        'content_type', 'object_repr', 
        'change_message')

    search_fields = ['=user__username', ]
    fieldsets = [
        (None, {'fields':()}), 
        ]

    def __init__(self, *args, **kwargs):
        super(LogEntryAdmin, self).__init__(*args, **kwargs)
        self.list_display_links = (None, )

It is kind of a mix between both answers.

If you just do self.list_display_links = () it will show the link, Anyway because the template-tag code (templatetags/admin_list.py) checks again to see if the list is empty.

60
12/3/2012 4:20:48 AM

Doing this properly requires two steps:

  • Hide the edit link, so nobody stumbles on the detail page (change view) by mistake.
  • Modify the change view to redirect back to the list view.

The second part is important: if you don't do this then people will still be able to access the change view by entering a URL directly (which presumably you don't want). This is closely related to what OWASP term an "Insecure Direct Object Reference".

As part of this answer I'll build a ReadOnlyMixin class that can be used to provide all the functionality shown.

Hiding the Edit Link

Django 1.7 makes this really easy: you just set list_display_links to None.

class ReadOnlyMixin(): # Add inheritance from "object" if using Python 2
    list_display_links = None

Django 1.6 (and presumably earlier) don't make this so simple. Quite a lot of answers to this question have suggested overriding __init__ in order to set list_display_links after the object has been constructed, but this makes it harder to reuse (we can only override the constructor once).

I think a better option is to override Django's get_list_display_links method as follows:

def get_list_display_links(self, request, list_display):
    """
    Return a sequence containing the fields to be displayed as links
    on the changelist. The list_display parameter is the list of fields
    returned by get_list_display().

    We override Django's default implementation to specify no links unless
    these are explicitly set.
    """
    if self.list_display_links or not list_display:
        return self.list_display_links
    else:
        return (None,)

This makes our mixin easy to use: it hides the edit link by default but allows us to add it back in if required for a particular admin view.

Redirecting to the List View

We can change the behaviour of the detail page (change view) by overriding the change_view method. Here's an extension to the technique suggested by Chris Pratt which automatically finds the right page:

enable_change_view = False

def change_view(self, request, object_id, form_url='', extra_context=None):
    """
    The 'change' admin view for this model.

    We override this to redirect back to the changelist unless the view is
    specifically enabled by the "enable_change_view" property.
    """
    if self.enable_change_view:
        return super(ReportMixin, self).change_view(
            request,
            object_id,
            form_url,
            extra_context
        )
    else:
        from django.core.urlresolvers import reverse
        from django.http import HttpResponseRedirect

        opts = self.model._meta
        url = reverse('admin:{app}_{model}_changelist'.format(
            app=opts.app_label,
            model=opts.model_name,
        ))
        return HttpResponseRedirect(url)

Again this is customisable - by toggling enable_change_view to True you can switch the details page back on.

Removing the "Add ITEM" Button

Finally, you might want to override the following methods in order to prevent people adding or deleting new items.

def has_add_permission(self, request):
    return False

def has_delete_permission(self, request, obj=None):
    return False

These changes will:

  • disable the "Add item" button
  • prevent people directly adding items by appending /add to the URL
  • prevent bulk delete

Finally you can remove the "Delete selected items" action by modifying the actions parameter.

Putting it all together

Here's the completed mixin:

from django.core.urlresolvers import reverse
from django.http import HttpResponseRedirect

class ReadOnlyMixin(): # Add inheritance from "object" if using Python 2

    actions = None

    enable_change_view = False

    def get_list_display_links(self, request, list_display):
        """
        Return a sequence containing the fields to be displayed as links
        on the changelist. The list_display parameter is the list of fields
        returned by get_list_display().

        We override Django's default implementation to specify no links unless
        these are explicitly set.
        """
        if self.list_display_links or not list_display:
            return self.list_display_links
        else:
            return (None,)

    def change_view(self, request, object_id, form_url='', extra_context=None):
        """
        The 'change' admin view for this model.

        We override this to redirect back to the changelist unless the view is
        specifically enabled by the "enable_change_view" property.
        """
        if self.enable_change_view:
            return super(ReportMixin, self).change_view(
                request,
                object_id,
                form_url,
                extra_context
            )
        else:
            opts = self.model._meta
            url = reverse('admin:{app}_{model}_changelist'.format(
                app=opts.app_label,
                model=opts.model_name,
            ))
            return HttpResponseRedirect(url)

    def has_add_permission(self, request):
        return False

    def has_delete_permission(self, request, obj=None):
        return False

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