consolidate content-series and default content partials

[aschweigert]

still a work in progress, fix for #1271, this replaces #1277

[aschweigert]

todo:

• deprecate tag display theme option (either always just set to "top" or figure out where else that's used in the theme and remove it)
• cleanup the way defaults are set here
• consider adding an action hook to modify the defaults instead of dumping all the series specific stuff directly in this file (it will eventually probably be in a plugin, let's start swimming in that direction)
• check defaults for largo_byline and largo_excerpt, make sure we still need all those args
• plan for migrating/deprecating youtube_url meta field since that's no longer really used (in favor of the newer featured media stuff)
• using "homepage featured" as the term to determine featuredness generally is probably a bad idea (at least as long as we have "featured in category" and "featured in series" prominence terms as well. we should probably respect those here instead/in addition.

[benlk]

Also, check that this still works with LMP in series.

[benlk]

Note to self:

consider adding an action hook to modify the defaults instead of dumping all the series specific stuff directly in this file (it will eventually probably be in a plugin, let's start swimming in that direction)

1. Put all the args in an associative array
2. Run the array through a filter with two args: the array and the queried object
3. Write a filter for terms that sets $array['featured'] to the taxonomy of the term

[benlk]

As far as removing the youtube_url-specific things, we can lose them in favor of largo_get_featured_media, which I believe will work with youtube_url-containing posts.

That will result in videos and embeds and galleries rendering as such, instead of using the thumbnail.

We could only display the thumbnail. @aschweigert is that an acceptable solution?

[benlk]

Thumbnails it is.

[benlk]

Getting the filter to work is making progress slow.

[benlk]

This will need to be updated with https://github.com/INN/Largo/pull/1291/files#diff-33b54c9d0b2a8a7010bb416509a2e69fR14

[benlk]

some docs on $opt here: https://github.com/INN/Largo/blob/master/series-landing.php

[benlk]

• remove the "show [ ] Categories/Tags" checkbox from the landing page editor
• check that no-landing-page series still look right
• re-check that largo's featured media stuff purports to function with the 0.3 youtube_url meta field
• why are tests failing?

[benlk]

New things in the PR:

• filter largo_content_partial_arguments to control what displays on the content partial
• filter function largo_content_partial_arguments_filter() hooked upon largo_content_partial_arguments to apply appropriate modifications to the arguments for series posts in accordance with series landing pages
• fix for bug Posts loaded via LMP on series landing pages don't respect the landing page's options #1326
• Removes rendering in partials/content.php of youtube videos as videos when the old youtube_url post meta was set
• Removes the "Show tags" control from featured landing pages, and associated functionality

Regarding the youtube_url meta value, that gets displayed on the single post templates by Largo's featured hero stuff. If a post with youtube_url is ever re-saved, then it gets converted to the normal featured media setup. That functionality has been around for a while, but I'm making a note of it here because Adam asked for a plan for migrating that.

@aschweigert, this is ready for review.