Note: This is a fork of Hexo-Generator-Category-Feed.

Background

We have a rather specific use case for which no community supported hexo plugins exist:

Given I am a reader of the blog
And I want to receive a newsletter (i.e. blog updates via email)
When I complete the newsletter signup form
And select each subject area that interests me
Then my newsletter should only include posts related to subjects I selected

Problem

MailChimp makes it very easy to create a signup form which includes check boxes for various subject areas. The bigger challenge is automatically creating and sending those emails every week. Luckily, MailChimp provides a handy RSS-to-Email feature. But, to use this feature, we need a separate RSS feed for each subject area.

Solution

Hexo has plugins for creating a single RSS feed as well as RSS feeds for each category. Unfortunately, those options are not quite what we need.

We need a simple way to specify which newsletters a post should be included in. This plugin lets you do just that by adding a little metadata to your post's front matter. For example, to include your post in the SPRJ newsletter:

newsletters:
- SPRJ

And, you can include a post in more than one newsletter:

newsletters:
- SPRJ
- LR

Finally, this will produce two separate RSS feeds:

http://blog.scholasticahq.com/lr-rss.xml
http://blog.scholasticahq.com/sprj-rss.xml

Which is exactly what we need to support MailChimp's RSS-to-Email feature!

Ordering

You can limit and order by fields

In the _config.yml add a sort_by key

Example:

feed:
  type: atom
  limit: 0
  sort_by:
    field: date
    direction: desc

Technical details

To accomplish this, we forked / hacked the Hexo-Generator-Category-Feed plugin. For more information, including a diff showing exactly what we changed, see https://github.com/scholastica/hexo-generator-feed-per-category/commit/586a0a9e422b2ebdd5c1678535a14b326a87a3dd.