# Customizing the comments framework

If the comment framework doesn’t quite fit your needs, you can extend the comment app’s behavior to add custom data and logic. The comments framework lets you extend the in comment model, the comment form, and the various comment views.

The `COMMENTS_APP` setting is where this customization begins. Set `COMMENTS_APP` to the name of the app you’d like to use to provide custom behavior. You’ll use the same syntax as you’d use for `INSTALLED_APPS`, and the app given must also be in the `INSTALLED_APPS` list.

For example, if you wanted to use an app named `my_comment_app`, your settings file would contain:

    INSTALLED_APPS = [
        ...
        'my_comment_app',
        ...
    ]

    COMMENTS_APP = 'my_comment_app'

The app named in `COMMENTS_APP` provides its custom behavior by defining some module-level functions in the app’s `__init__.py`. The complete list of these functions can be found below, but first let’s look at a quick example.

## An example custom comments app

One of the most common types of customization is modifying the set of fields provided on the comment model. For example, some sites that allow comments want the commentator to provide a title for their comment; the comment model has no field for that title.

To make this kind of customization, we’ll need to do three things:

1. Create a custom comment `Model` that adds on the “title” field.

2. Create a custom comment `Form` that also adds this “title” field.

3. Inform Django of these objects by defining a few functions in a custom `COMMENTS_APP`.

So, carrying on the example above, we’re dealing with a typical app structure in the `my_comment_app` directory:

    my_comment_app/
        __init__.py
        models.py
        forms.py

In the `models.py` we’ll define a `CommentWithTitle` model:

    from django.db import models
    from django_comments.abstracts import CommentAbstractModel

    class CommentWithTitle(CommentAbstractModel):
        title = models.CharField(max_length=300)

Most custom comment models will subclass the `CommentAbstractModel` model. However, if you want to substantially remove or change the fields available in the `CommentAbstractModel` model, but don’t want to rewrite the templates, you could try subclassing from `BaseCommentAbstractModel`.

Next, we’ll define a custom comment form in `forms.py`. This is a little more tricky: we have to both create a form and override `CommentForm.get_comment_create_data()` to return deal with our custom title field:

    from django import forms
    from django_comments.forms import CommentForm
    from my_comment_app.models import CommentWithTitle

    class CommentFormWithTitle(CommentForm):
        title = forms.CharField(max_length=300)

        def get_comment_create_data(self, **kwargs):
            # Use the data of the superclass, and add in the title field
            data = super().get_comment_create_data(**kwargs)
            data['title'] = self.cleaned_data['title']
            return data

Django provides a couple of “helper” classes to make writing certain types of custom comment forms easier; see `django_comments.forms` for more.

Finally, we’ll define a couple of methods in `my_comment_app/__init__.py` to point Django at these classes we’ve created:

    def get_model():
        from my_comment_app.models import CommentWithTitle
        return CommentWithTitle

    def get_form():
        from my_comment_app.forms import CommentFormWithTitle
        return CommentFormWithTitle

The class imports have to be inside functions, as recent Django versions do not allow importing models in the application root `__init__.py` file.

Warning

Be careful not to create cyclic imports in your custom comments app. If you feel your comment configuration isn’t being used as defined – for example, if your comment moderation policy isn’t being applied – you may have a cyclic import problem.

If you are having unexplained problems with comments behavior, check if your custom comments application imports (even indirectly) any module that itself imports Django’s comments module.

The above process should take care of most common situations. For more advanced usage, there are additional methods you can define. Those are explained in the next section.

## Custom comment app API

The `django_comments` app defines the following methods; any custom comment app must define at least one of them. All are optional, however.

django_comments.get_model()

  Return the `Model` class to use for comments. This model should inherit from `django_comments.abstracts.BaseCommentAbstractModel`, which defines necessary core fields.

  The default implementation returns `django_comments.models.Comment`.

django_comments.get_form()

  Return the `Form` class you want to use for creating, validating, and saving your comment model. Your custom comment form should accept an additional first argument, `target_object`, which is the object the comment will be attached to.

  The default implementation returns `django_comments.forms.CommentForm`.

  Note

  The default comment form also includes a number of unobtrusive spam-prevention features (see Notes on the comment form). If replacing it with your own form, you may want to look at the source code for the default form and consider incorporating similar features.

django_comments.get_form_target()

  Return the URL for POSTing comments. This will be the `<form action>` attribute when rendering your comment form.

  The default implementation returns a reverse-resolved URL pointing to the `post_comment()` view.

  Note

  If you provide a custom comment model and/or form, but you want to use the default `post_comment()` view, you will need to be aware that it requires the model and form to have certain additional attributes and methods: see the `django_comments.views.post_comment()` view for details.

django_comments.get_flag_url()

  Return the URL for the “flag this comment” view.

  The default implementation returns a reverse-resolved URL pointing to the `django_comments.views.moderation.flag()` view.

django_comments.get_delete_url()

  Return the URL for the “delete this comment” view.

  The default implementation returns a reverse-resolved URL pointing to the `django_comments.views.moderation.delete()` view.

django_comments.get_approve_url()

  Return the URL for the “approve this comment from moderation” view.

  The default implementation returns a reverse-resolved URL pointing to the `django_comments.views.moderation.approve()` view.