[PATCH v5 2/7] models: Add 'Series' model and related models

[Andy Doan]

On 10/09/2016 05:25 PM, Stephen Finucane wrote:
> Add a series model. This model is intentionally very minimal to allow
> as much dynaminism as possible. It is expected that patches will be
> migrated between series as new data is provided.
> 
> Signed-off-by: Stephen Finucane <stephen at that.guru>
> ---

> diff --git a/patchwork/models.py b/patchwork/models.py
> index 28e9861..4a55c1d 100644
> --- a/patchwork/models.py
> +++ b/patchwork/models.py
> @@ -293,7 +293,7 @@ class EmailMixin(models.Model):

>  class CoverLetter(Submission):
> -    pass
> +
> +    @property
> +    def series(self):
> +        """Get a simple series reference.
> +
> +        Return the last series revision that (ordered by date) that
> +        this submission is a member of.
> +
> +        .. warning::
> +          Be judicious in your use of this. For example, do not use it
> +          in list templates as doing so will result in a new query for
> +          each item in the list.
> +        """
> +        # NOTE(stephenfin): We don't use 'latest()' here, as this can raise an
> +        # exception if no series revisions exist
> +        return self.series_revisions.order_by('-date').first()

I see this method both here and in the Patch class. Couldn't we just put
it in the Submission class once and avoid the duplication?