Co-Authors Plus

Contributors: batmoo, danielbachhuber, automattic
Tags: authors, users, multiple authors, co-authors, multi-author, publishing
Tested up to: 5.7
Requires at least: 4.1
Stable tag: 3.4.5

Assign multiple bylines to posts, pages, and custom post types via a search-as-you-type input box

Description

Assign multiple bylines to posts, pages, and custom post types via a search-as-you-type input box. Co-authored posts appear on a co-author's archive page and in their feed. Co-authors may edit the posts they are associated with, and co-authors who are contributors may only edit posts if they have not been published (as is core behaviour).

Add writers as bylines without creating WordPress user accounts. Simply create a guest author profile for the writer and assign the byline as you normally would.

On the frontend, use the Co-Authors Plus template tags to list co-authors anywhere you'd normally list the author.

This plugin is an almost complete rewrite of the Co-Authors plugin originally developed by Weston Ruter (2007). The original plugin was inspired by the 'Multiple Authors' plugin by Mark Jaquith (2005).

Frequently Asked Questions

How do I add Co-Authors Plus support to my theme?

If you've just installed Co-Authors Plus, you might notice that the bylines are being added in the backend but aren't appearing on the frontend. You'll need to add the template tags to your theme before the bylines will appear.

What happens to posts and pages when I delete a user assigned to a post or page as a coauthor?

When a user is deleted from WordPress, they will be removed from all posts for which they are co-authors. If you chose to reassign their posts to another user, that user will be set as the coauthor instead.

Can I use Co-Authors Plus with WordPress multisite?

Yep! Co-Authors Plus can be activated on a site-by-site basis, or network-activated. If you create guest authors, however, those guest authors will exist on a site-by-site basis.

Who needs permission to do what?

To assign co-authors to posts, a WordPress user will need the edit_others_posts capability. This is typically granted to the Editor role, but can be altered with the coauthors_plus_edit_authors filter.

To create new guest author profiles, a WordPress will need the list_users capability. This is typically granted to the Administrator role, but can be altered with the coauthors_guest_author_manage_cap filter.

Can I easily create a list of all co-authors?

Yep! There's a template tag called coauthors_wp_list_authors() that accepts many of the same arguments as wp_list_authors(). Look in template-tags.php for more details.

I have a large database, will this make it slow?

If the site has a large database, you may run into issues with heavier than usual queries. You can work around this by disabling compat mode and force it to use simpler, tax-only queries by adding the following to your theme:

// Use simple tax queries for CAP to improve performance
add_filter( 'coauthors_plus_should_query_post_author', '__return_false' );

Note that this requires the site(s) to have proper terms set up for all users. You can do this with the following wp-cli command:

# This is pretty long-running and can be expensive; be careful!
$ wp --url=example.com co-authors-plus create-terms-for-posts

How do I use custom post types?

To ensure posts with your CPT are counted, use the coauthors_count_published_post_types filter.

add_filter( 'coauthors_count_published_post_types', function( $post_types ) {
   $post_types[] = 'my_cpt_slug';
   return $post_types;
} );

To display the metabox on your CPT, either call register_post_type() with $args['supports'] containing 'author', or call add_post_type_support( 'my_cpt_slug', 'author' );

Changelog

3.4.5

Fixed bug where guest authors with spaces in names were not showing when queried in AJAX suggest box.

3.4.4

Fixed bug where author with slug beginning with "cap" does not appear in bylines AJAX suggest box when queried #744
Travis for Xenial build no longer fails #751
Unit tests no longer fail #752
Fixed REST permissions bug where co-author cannot view post assigned to them in Gutenberg #757

3.4.3

Added author support to CPT instructions in readme FAQ #720
Added object check for user in coauthors_set_post_author_field() #721
Fix inefficient user query in avatar url hook #724
Fix operand typo in get_guest_author_thumbnail() for adding custom classes #725
Remove hardcoded default avatar and use default option #728

3.4.2

Fix incorrect user avatar being displayed from featured post image #706
Add check for filter_get_avatar_url to ensure valid second parameter #707
add_coauthors() accepts ID parameter now #685 and ensures valid term slug used #708
filter_count_user_posts checks that user ID returns valid user object #714
Added post count instructions in readme FAQ for CPTs #713

3.4.1

Fix an issue that may arise in bulk edit #700

3.4

New filter get_coauthors for modifying coauthor data returned in get_coauthors() #646
New filter coauthors_guest_authors_exported_extra_data to allow guest author to export data as regular author #528
New filter get_avatar_url() to show avatar in JS selection #621
New parameter in coauthors_wp_list_authors() to only query authors with posts #496
Add internationalization support to title and name in author archives #516
Add safelist to skip irrelevant capabilities during permission checks #543
Add helper function get_guest_author_post_count() #605
Add parameter for outputting HTML classes in coauthors_get_avatar() template tag #610
Add --append_coauthors flag to synopsis of CLI assign-coauthors #600
Adjust CLI command create-guest-authors-from-csv to import website, avatar and description (#603 and #619)
Post type of "any" can be used in filters #617
Remove unnecessary is_array() check #471
Remove unnecessary action_pre_user_query() #531
Use correct args in search_authors() #519
Have filter_author_archive_title() run on author archives only #535
Improve tests coverage (#529, #540, #546, #576 and #569)
Change posts_selection to action from filter #563
Fix number of args expected for get_the_archive_title callback #657
Fix spelling, update FAQ for disabling guest authors and credits in readme (#656, #523 and #501)
Output coauthors_links_single() template tag correctly when guest author has no website #504
Number by "Mine" link shows correct listing of posts #663
Linked guest authors show accurate post counts #674
Can no longer add co-author more than once #532
No more overwriting posts with current user in add_coauthors() #545
Accurate post count for user when using different login #558
No more double post count for users with linked accounts #567
Fix SQL error (#593 and #628)
Fix "Mine" link href for Pages #547
Can delete users when guest authors functionality disabled #602
Fix incompatibility issue with Yoast of missing posts in author pages #624
Resolve undefined index warnings on author archives #521
Resolve warnings when current user has no term assigned #517

Props: TheCrowned, shantanu2704, WPprodigy, blunce24, rebeccahum, andrewfleming, justnorris, sboisvert, jasonbahl, mariovalney, RoyTheRoyalBoy, jacobarriola, smistephen, manzoorwanijk, kodemonster, westonruter, binodkalathil, scofennell, hyperionjrw, pdemarte, mostafaabd, paulschreiber

3.3.1 ("Gutentag")

5.0 Compat: Hide core author inputs when using the Block Editor to limit confusion (h/t jonathanstegall).

3.3.0 ("Rebecca")

Fix private post viewing on front-end #386
Reduce amount of sleep #400
Author search UX issues #407
Remove associated guest user when mapped user id deleted. #414
Removed double left join on posts_join_filter #419
Fixed WP CLI create-terms-for-posts if no co-authors found #420
Pages archive now displays co-authors and quick edit works #422
Terminology updated throughout #423
Replace hardcoded 'author' with $this->$coauthor_taxonomy #426
Move parenthesis to fix esc_html and sprintf #430
Added progress to create-guest-authors so users have an idea of how long it will take #431
Deleting guest authors is less confusing #432
Guest author's featured image is avatar now #433
Removed extra image sizing #434
Remove duplicated byline #435
coauthors_wp_list_authors() has option to list only guest authors now #436
remove duplicates from linked accounts on coauthors_wp_list_authors() #437
Accurate Guest Author post count on linked accounts #438
New README.md #439
Filter author archive #441
Fix coauthors_links_single() #444
Added guest author hooks for create/delete #446
Fixes logic for DOING_AUTOSAVE check #450
user_login spaces problem when using add_coauthors #453
Adding details of filter for slow performance #456
Remove redundant test for 404 on Author Archive #457
Guest Author Counts are more accurate #461
Set $coauthors_loading #468
Fix the issue where guest authors with non-ASCII characters can't be used as co-authors #473
Fix the issue where incompatibility when coauthors_auto_apply_template_tags set to true #474
Unit tests/Fix warnings for template tags #475
Review and improve test coverage #476
Update class-wp-cli.php #480
Update .travis.yml file for PHPUnit tests #482
Changes to resolve issue #332 about missing coauthor meta #484

Props to the many people who helped make this release possible: catchmyfame, danielbachhuber, david-binda, douglas-johnson, castlehouse, frankar, haleeben, jjeaton, johnbillion, kevinlisota, mattoperry, mdbitz, mdchiragpatel, megfh, mjangda, mslinnea, natebot, nickdaugherty, nilzari, philipjohn, pkevan, rebeccahum, ryanmarkel, sanketio, sboisvert, Spongsta, srguglielmo, timburden, trepmal, TylerDurdon

3.2.2

Fix broken author ordering in 4.7+ (props mslinnea)
Fix no moderation e-mail bug (props RobjS)
Cached functions in CLI commands (props jasonbahl)
Fix missing echos (props trepmal)
Add coauthors_guest_author_query_args filter (props trepmal)

3.2.1 (May 16, 2016)

Hotfix for broken Guest Author bio metabox (props JS Morisset)

3.2 (May 12, 2016)

Various minor bug and security fixes

3.1.2 (Aug. 31, 2015)

Minor bug fixes and coding standards changes.
The author's display name is now filtered through the_author in coauthors_posts_links_single()
New Russian and Ukrainian translations, courtesy of Jurko Chervony.

3.1.1 (Mar. 20, 2014)

Bug fix: Co-authors selection UI should appear when creating a new post too.

3.1 (Mar. 17, 2014)

Manage co-authors from Quick Edit. Props mpatek.
Updated Spanish translation, courtesy of sergiomajluf.
Now matches core behavior when displaying author archive on multisite: user of the blog, or previously published author on the blog.
Breaking change: "Create Profile" link is no longer shown by default on the Manage Users screen. Instead, it can be enabled with the coauthors_show_create_profile_user_link filter.
Guest authors work properly with Jetpack Open Graph tags. Props hibernation.
Guest author profile editor now supports a few different fields. Props alpha1.
New coauthors_count_published_post_types filter for specifying the post type(s) used when calculating the user's number of published posts.
Bug fix: Ensure post_author is set to one of the co-authors assigned to a post.
Bug fix: Filter author feed link for guest authors on the author page. Props hibernation.
Packages a composer.json file for those using Composer.
Beginnings of unit test coverage for core features. Increased minimum required WordPress version to 3.7 because WordPress.org unit testing framework doesn't work reliabilty below that.

3.0.7 (Jan. 27, 2014)

Better support for installing Co-Authors Plus as a symlinked directory. Follow these instructions to filter plugins_url.
Links to authors' posts pages to comply to hCard microformat, which Google depends on.
New coauthors_emails() template tag to list email addresses of the co-authors. Props benlk.
Bug fix: Remove extraneous space between last two co-authors output. Props johnciacia.
Updated French translation, courtesy of Jojaba (via email).

3.0.6 (Dec. 9, 2013)

New Swedish translation, courtesy of alundstroem
Updated German translation, courtesy of krafit.
New Dutch translation, courtesy of kardotim
New filter for specifying the default author assigned to a post. Props tannerm
Bug fix: When filtering a user's published post count, use the value of their guest author profile if one is mapped.
Added support for checkboxes in Guest Author profiles
Fix Strict warnings from CPT's that don't define all capabilities
New swap-coauthors CLI command for replacing one co-author with another

3.0.5 (Feb. 18, 2013)

New filter coauthors_search_authors_get_terms_args allows you to increase the number of matches returned with AJAX co-author selection
Bug fix: If there isn't an author term yet for a co-author, avoid an erronous join that caused duplicate posts to appear.

3.0.4 (Jan. 6, 2013) =

Support for automatically adding co-authors to your feeds. Props cfg.
Bug fix: No Co-Authors Plus on attachments. For now.
Bug fix: Better support for co-authors with non-standard user_nicenames. Props STRML.

3.0.3 (Dec. 3, 2012)

Bug fix: The default order for the 'author' taxonomy should be term_order, in order for the author positions to stick. Props lgedeon

3.0.2 (Nov. 23, 2012)

Bug fix: Fall back to non-pretty permalinks when the author permastruct is empty, so that coauthors_posts_links() doesn't link to the homepage

3.0.1 (Nov. 21, 2012)

Add your own custom columns to the guest authors table using filters. Props cfg
A new wp-cli subcommand for renaming co-authors and another for removing author terms mistakenly assigned to revisions
Bug fix: Using a featured image for a guest author avatar didn't work. Now it does.
Bug fix: Don't assign author terms to revisions to avoid unnecessary database bloat
Bug fix: Make the coauthors_wp_list_authors() template tag work again
Bug fix: Improve capability filtering by properly handling super admin access and situations where user_id = 0
Minor UI enhancements for guest authors

3.0 (Nov. 12, 2012)

Create guest author profiles for bylines you'd like to assign without creating WordPress user accounts. Guest authors can have all of the same fields as normal users including display name, biography, and avatars.
Support for non-Latin characters in usernames and guest author names
wp-cli subcommands for creating, assigning, and reassigning co-authors
For themes using core template tags like the_author() or the_author_posts_link(), you enable Co-Authors Plus support with a simple filter
New author terms are now prefixed with cap- to avoid collisions with global scope
Bug fix: Apply query filters to only post_types registered with the taxonomy. Props Tom Ransom
Filter coauthors_posts_link_single() with coauthors_posts_link. Also adds rel="author". Props Amit Sannad and Gabriel Koen
Filter for the context and priorities of the Co-Authors meta boxes. Props Tomáš Kapler
Renamed the post meta box for selecting authors so it applies to many post types. Props John Blackbourn

2.6.4 (May 7, 2012)

Bug fix: Properly filter the user query so users can AJAX search against the display name field again
If https is used for the admin, also use the secure Gravatar URL. Props rmcfrazier

2.6.3 (Apr. 30, 2012)

AJAX user search is back to searching against user login, display name, email address and user ID. The method introduced in v2.6.2 didn't scale well
French translation courtesy of Sylvain Bérubé
Spanish translation courtesy of Alejandro Arcos
Bug fix: Resolved incorrect caps check against user editing an already published post. See forum thread

2.6.2 (Mar. 6, 2012)

AJAX user search matches against first name, last name, and nickname fields too, in addition to display name, user login, and email address
Comment moderation and approved notifications are properly sent to all co-authors with the correct caps
Filter required capability for user to be returned in an AJAX search with coauthors_edit_author_cap
Filter out administrators and other non-authors from AJAX search with coauthors_edit_ignored_authors
Automatically adds co-authors to Edit Flow's story budget and calendar views
Bug fix: Don't set post_author value to current user when quick editing a post. This doesn't appear in the UI anywhere, but adds the post to the current user's list of posts
Bug fix: Properly cc other co-authors on new comment email notifications
Bug fix: If a user has already been added as an author to a post, don't show them in the AJAX search again
Bug fix: Allow output constants to be defined in a theme's functions.php file and include filters you can use instead

2.6.1 (Dec. 30, 2011)

Fix mangled usernames because of sanitize_key http://wordpress.org/support/topic/plugin-co-authors-plus-26-not-working-with-wp-33

2.6 (Dec. 22, 2011)

Sortable authors: Drag and drop the order of the authors as you'd like them to appear (props kingkool68)
Search for authors by display name (instead of nicename which was essentially the same as user_login)
Option to remove the first author when there are two or more so it's less confusing
Bumped requirements to WordPress 3.1
Bug fix: Update the published post count for each user more reliably

2.5.3 (Aug. 14, 2011)

Bug fix: Removed extra comma when only two authors were listed. If you used the COAUTHORS_DEFAULT_BETWEEN_LAST constant, double-check what you have

2.5.2 (Apr. 23, 2011)

Bug: Couldn't query terms and authors at the same time (props nbaxley)
Bug: Authors with empty fields (e.g. first name) were displaying blank in some cases
Bug: authors with spaces in usernames not getting saved (props MLmsw, Ruben S. and others!)
Bug: revisions getting wrong user attached (props cliquenoir!)

2.5.1 (Mar. 26, 2011)

Fix with author post count (throwing errors)

2.5 (Mar. 26, 2011)

Custom Post Type Support
Compatibility with WP 3.0 and 3.1
Gravatars
Lots and lots and lots of bug fixes
Thanks to everyone who submitted bugs, fixes, and suggestions! And for your patience!

2.1.1 (Oct. 16, 2009)

Fix for co-authors not being added if their username is different from display name
Fixes to readme.txt (fixes for textual and punctuation errors, language clarification, minor formatting changes) courtesy of Waldo Jaquith

2.1 (Oct. 11, 2009)

Fixed issues related to localization. Thanks to Jan Zombik zombik@students.uni-mainz.de for the fixes.
Added set_time_limit to update function to get around timeout issues when upgrading plugin

2.0 (Oct. 11, 2009)

Plugin mostly rewritten to make use of taxonomy instead of post_meta
Can now see all authors of a post under the author column from Edit Posts page
All authors of a post are now notified on a new comment
Various javascript enhancements
New option to allow subscribers to be added as authors
All Authors can edit they posts of which they are co-authors
FIX: Issues with wp_coauthors_list function
FIX: Issues with coauthored posts not showing up on author archives

1.2.0 (Jun. 16, 2012)

FIX: Added compatibility for WordPress 2.8
FIX: Added new template tags (get_the_coauthor_meta & the_coauthor_meta) to fix issues related to displaying author info on author archive pages. See Other Notes for details.
FIX: Plugin should now work for plugins not using the wp_ DB prefix
FIX: Coauthors should no longer be alphabetically reordered when the post is updated
FIX: Plugin now used WordPress native AJAX calls to tighten security
DOCS: Added details about the new template tags

1.1.5 (Apr. 26, 2009)

FIX: Not searching Updated SQL query for autosuggest to search through first name, last name, and nickname
FIX: When editing an author, and clicking on a suggested author, the original author was not be removed
DOCS: Added code comments to javascript; more still to be added
DOCS: Updated readme information

1.1.4 (Apr. 25, 2009)

Disabled "New Author" output in suggest box, for now
Hopefully fixed SVN issue (if you're having trouble with the plugin, please delete the plugin and reinstall)

1.1.3 (Apr. 23, 2009)

Add blur event to disable input box
Limit only one edit at a time.
Checked basic cross-browser compatibility (Firefox 3 OS X, Safari 3 OS X, IE7 Vista).
Add suggest javascript plugin to Edit Page.

1.1.2 (Apr. 19, 2009)

Disabled form submit when enter pressed.

1.1.1 (Apr. 15, 2009)

Changed SQL query to return only contributor-level and above users.

1.1.0 (Apr. 14, 2009)

Initial beta release.

Installation

IMPORTANT: Please disable the original Co-Authors plugin (if you are using it) before installing Co-Authors Plus
Extract the coauthors-plus.zip file and upload its contents to the /wp-content/plugins/ directory. Alternately, you can install directly from the Plugin directory within your WordPress Install.
Activate the plugin through the "Plugins" menu in WordPress.
Place the appropriate co-authors template tags in your template.
Add co-authors to your posts and pages.

Screenshots