Allow custom Atom author elements such as email

[niallkennedy]

The Atom Syndication Format includes ​person constructs to describe a "person, corporation, or similar entity." WordPress builds an author element in its Atom template with support for a 'name' or 'uri' child element only. Publishers may want to include an author's email address but have no way to add in the extra information without editing the core template file.

Publishing an email contact for each author is fairly common in mainstream media to engage readership through their communication method of choice. A feed reader connected to an email client such as Outlook might support responding to an entry via email. My local newspaper, the San Francisco Chronicle, publicly ​lists the email addresses of its staff with each article.

I am trying to add child elements to the author element, meaning the atom_entry action won't help.

Attached is a patch to build the author person construct as an associative array, pass it to a filter, and echo to screen. Plugins could include additional author data including email or extension elements.

I think it would be better just to put an action in the feed-atom file for plugins to hook into.

Simpler to use and they can add whatever they like then and it keeps the bulk of the required stuff in the theme file - the current patch makes it possible for a badly written plugin to strip the whole author section out of the feed.

Allow custom author elements such as email by adding an action

New attached diff with an 'atom_author' action called before closing the entry's author element.

(In [17641]) Allow custom author elements such as email. Fixes #17149 props niallkennedy.