django-secretballot 2.0.0

Django anonymous voting application.

django-secretballot

Django voting application that allows voting without a logged in user.

Provides abstract base model for types that the user wishes to allow voting on as well as related utilities including generic views to ease the addition of ‘anonymous’ voting to a Django project.

Maintained by Basil Shubin, and some great contributors.

Installation

First install the module, preferably in a virtual environment. It can be installed from PyPI:

pip install django-secretballot

Setup

First of all, you must add this project to your list of INSTALLED_APPS in settings.py :

INSTALLED_APPS += [
    "secretballot",
]

There is only one mandatory configuration option you need to set in your settings.py:

# In order to attach the voting helpers to a particular model it is enough
# to list them here...
SECRETBALLOT_FOR_MODELS = {
    "<app_label.model_name>": {},
}

Run ./manage.py migrate. This creates the tables in your database that are necessary for operation.

Please see example application. This application is used to manually test the functionalities of this package. This also serves as a good example.

You need Django 1.8 or above to run that. It might run on older versions but that is not tested.

Using voting-enabled models

Once a model is voting-enabled a number of special fields are available on all instances:

Fields

Votable objects have the following fields:

votes

Manager to of all Vote objects related to the current model (typically doesn’t need to be accessed directly). Can be renamed by passing votes_name parameter to SECRETBALLOT_FOR_MODELS, for example:

SECRETBALLOT_FOR_MODELS = {
    "<app_label.model_name>": {
        "votes_name": "vs",
    },
}

total_upvotes

Total number of +1 votes. Can be renamed by passing upvotes_name parameter to SECRETBALLOT_FOR_MODELS, for example:

SECRETBALLOT_FOR_MODELS = {
    "<app_label.model_name>": {
        "upvotes_name": "total_upvs",
    },
}

total_downvotes

Total number of -1 votes. Can be renamed by passing downvotes_name parameter to SECRETBALLOT_FOR_MODELS, for example:

SECRETBALLOT_FOR_MODELS = {
    "<app_label.model_name>": {
        "downvotes_name": "total_downvs",
    },
}

vote_total

Shortcut accessor for (total_upvotes minus total_downvotes). Can be renamed by passing total_name parameter to SECRETBALLOT_FOR_MODELS, for example:

SECRETBALLOT_FOR_MODELS = {
    "<app_label.model_name>": {
        "total_name": "v_total",
    },
}

_secretballot_enabled

Boolean indicating that secretballot is enabled (can be tested for with hasattr). Cannot be renamed, exists for a reliable check that secretballot is available even if all other fields were renamed.

Methods

Votable objects have the following custom methods:

add_vote

Function that takes a token and a vote (+1 or -1) and adds or updates the vote for said token. Can be renamed by passing add_vote_name parameter to SECRETBALLOT_FOR_MODELS, for example:

SECRETBALLOT_FOR_MODELS = {
    "<app_label.model_name>": {
        "add_vote_name": "add_v",
    },
}

remove_vote

Function that takes a token and removes the vote (if present) for said token. Can be renamed by passing remove_vote_name parameter to SECRETBALLOT_FOR_MODELS, for example:

SECRETBALLOT_FOR_MODELS = {
    "<app_label.model_name>": {
        "remove_vote_name": "remove_v",
    },
}

Manager functions

A special manager is added that enables the inclusion of total_upvotes and total_downvotes as well as some extra functionality.

This manager by default replaces the objects manager, but this can be altered by passing the manager_name parameter to SECRETBALLOT_FOR_MODELS, for example:

SECRETBALLOT_FOR_MODELS = {
    "<app_label.model_name>": {
        "manager_name": "ballot_custom_manager",
    },
}

There is also an additional method on the Votable manager:

from_request(self, request)

When called on a votable object’s queryset will add a user_vote attribute that is the vote cast by the current ‘user’ (actually the token assigned to the request), for example:

def story_view(request, slug):
    story = Story.objects.from_request(request).get(pk=slug)
    # story has the following extra attributes
    # user_vote: -1, 0, or +1
    # total_upvotes: total number of +1 votes
    # total_downvotes: total number of -1 votes
    # vote_total: total_upvotes-total_downvotes
    # votes: related object manager to get specific votes (rarely needed)

Tokens and SecretBallotMiddleware

Without user logins it is impossible to be certain that a user does not vote more than once, but there are several methods to limit abuses. secretballot takes a fairly hands-off approach to this problem, the Vote object has a token field that is used to store a uniquely identifying token generated from a request. To limit how many votes come from a particular ip address it is sufficient to set the token to the IP address, but it is also possible to develop more sophisticated heuristics to limit voters.

secretballot uses a simple piece of middleware to do this task, and makes it trival for users to define their own middleware that will use whatever heuristic they desire.

SecretBallotMiddleware is an abstract class that defines a generate_token(request) method that should return a string to be used for the token.

For convenience several middleware have already been defined:

SecretBallotIpMiddleware

Simply sets the token to request.META['REMOTE_ADDR'] – the user’s IP address

SecretBallotIpUseragentMiddleware

Sets the token to a hash of the user’s ip address and user agent – hopefully slightly more unique than IP alone

If you wish to define your own middleware simply derive a class from SecretBallotMiddleware and implement the generate_token method. If you come up with something that may be useful for others contributions are always welcome.

Generic Views

secretballot.views includes the following generic views:

secretballot.views.vote

Description:

This view creates or alters a vote on the object of content_type with a primary key of object_id. If a vote already exists it will be replaced (unless vote is 0 in which case it will be deleted).

The token attribute of the vote that is used to prevent unlimited voting is set within this view based on the active SecretBallotMiddleware.

Depending on the parameters given the return value of this view varies:

1. if redirect_url is specified it will be used no matter what

2. if template_name is specified it will be used (along with template_loader, context_processors and etc.)

3. without redirect_url or template_name a text/json response will be returned

Required arguments:

• content_type : class that voting is taking place on (a VotableModel-derived model).

  May be an instance of django.contrib.contenttypes.models.ContentType, the Model class itself, or an <app_label.model_name> string.

• object_id : primary key of object to vote on

• vote : value of this vote (+1, 0, or -1) (0 deletes the vote)

Optional arguments:

• can_vote_test : function that allows limiting if user can vote or not. It’s an optional argument to the view that can be specified in the urlconf that is called before a vote is recorded for a user.

  Example implementation of can_vote_test:

  from secretballot.utils import get_vote_model
  
  def only_three_votes(request, content_type, object_id, vote):
      return get_vote_model().objects.filter(content_type=content_type, token=request.secretballot_token).count() < 3

  All can_vote_test methods must take the non-optional parameters to secretballot.views.vote and should return True if the vote should be allowed. If the vote is not allowed by default the view will return a 403, but it is also acceptable to raise a different exception.

• redirect_url : url to redirect to, if present will redirect instead of returning a normal HttpResponse

• template_name : template to render to, recieves a context containing content_obj which is the object voted upon

• template_loader : template loader to use, defaults to django.template.loader

• extra_context : dictionary containing any extra context, callables will be called at render time

• context_processors : list of context processors for this view

• mimetype : mimetype override

Credits

django-secretballot was originally started by James Turk who has now unfortunately abandoned the project.

License

django-secretballot is released under the BSD license.

Changes

2.0.0 (2021-10-26)

• drop compatibility code for Django 1.10 and below

• make it possible to customize Vote model per project

1.0.0 (2017-12-05)

• final release that supports Django 1.8 and up

0.7.1 (2017-10-03)

• improved support for Django 2.0

0.7.0 (2017-05-05)

• improved support for Django 1.11

0.6.0 (2016-10-07)

• support for Django 1.10 new manager rules

• add migrations

• fix case where object is not fetched through correct manager

0.5.0 (2015-11-02)

• drop South support

• drop support for Django < 1.8, add support for Django 1.9

0.4.0 (2015-05-27)

• drop South support

• drop support for Django < 1.7, add support for Django >= 1.7

• add Python 3 support

• add a ton of tests

• fix bug if vote_name was set in enable_voting_on

0.3.0 (2015-04-17)

• related_fields and get_object_or_404 fix from François Chapuis

• add property to check if secretballot is present on a class

• add indexed timestamps to votes via Simon de Han

• make response valid JSON for mimetype compatibility via Dan Drinkard

0.2.3 (2010-03-30)

• bugfixes, thanks to Gennadiy Potapov

0.2.2 (2009-11-27)

• fixed embarassing SyntaxError in vote

0.2.1 (2009-11-24)

• fix some documentation issues left from 0.1

• make content_type more flexible (can now take a model, content_type, or ‘app.model’ string)

0.2.0 (2009-02-11)

• replace inheritance from VotableObject with enable_voting_on

• when injecting manager methods inherit from existing manager

0.1.0 (2009-01-24)

• initial working release