How to add an attribute to the body tag with a plugin?

It doesn’t appear that you can (easily) add arbitrary attributes to the <body> tag.

However, WordPress provides the function body_class() so you can add classes to the <body> tag.

If your theme uses it, you’ll find something along these lines in a template file (eg. header.php):

<body <?php body_class(); ?>>

In that case, you’ll be able to filter the array of classes being passed using the body_class filter:

add_filter( 'body_class', 'wpse388651_body_class' );
function wpse388651_body_class( $classes ) {
    $classes[] = 'my-custom-class';
    return $classes;
}

Related Posts:

  1. dealing with large HTML output via plugin code
  2. How can I make my custom shortcode work in a Custom HTML Widget?
  3. Output in XHTML or HTML 5 for plugins?
  4. Editor not displaying dynamically after clicking on the button
  5. How to make a custom field as an editor in wordpress?
  6. How to trigger $_GET request within admin plugin page?
  7. How can I get WordPress to save comments in markdown format?
  8. How can i get the post’s full html source by its ID?
  9. Images under 1MB are not being compressed
  10. How to save Setting pages data to the database?
  11. How to translate to spanish wordpress hardcoded content/files?
  12. Can’t access 3rd party API, code works on local server but not on wordpress
  13. Form tries to download a file on submit
  14. hide load more button if there are no posts left to display
  15. How to create a “Most Popular” & “Latest” TAB in WordPress
  16. is_plugin_active function doesn’t exist
  17. How can I find plugins’ slug?
  18. How to call a plugin function from index.php
  19. My custom made plugin has “a new version available” which links to unrelated plugin
  20. Where can I find a schema of wordpress plugin core architecture?
  21. How to remove duplicate sub-menu name for top level menu items in a plugin?
  22. WordPress Plugin Development from Scratch. How? [closed]
  23. How to fetch serialized data from wordpress options
  24. Passing URL parameters to WordPress pages and pretty url
  25. WordPress network: set themes and plugins for new blog
  26. How to get the custom page get_permalink?
  27. Plugin translations problem
  28. How can I add a custom meta value on file upload?
  29. Advanced Custom Fields into functions.php
  30. How ( and mostly at what time ) can i prevent the alternate cron from running?
  31. Admin-ajax.php is dying “0” without processing function
  32. How do I register a stylesheet inside a WordPress widget?
  33. WordPress register_activation_hook table creation not working
  34. How to remove an Ajax action
  35. nonces in custom oop plugin
  36. I would like to use create a function in my custom plugin to tell WP to use a different header
  37. WordPress plugin for mail subscriptions [closed]
  38. Escape when echoed
  39. How to remove the woocommerce_checkout_process action hook in woocommerce if particular project in cart [closed]
  40. WP_Query ordering numbers as letters
  41. WordPress Automatic Plugin Update Renames Plugin Directory
  42. ‘wp_login’ action hook not working with wp-login.php file
  43. Execute a plugin only on post pages
  44. HTML in WooCommerce settings
  45. Can WordPress Plugin Directory Cache Delay the Upload of Images?
  46. Redirecting to home page after login as custom role WordPress
  47. Where (or when) should I register a new taxonomy?
  48. Create dynamic page content from custom WordPress plugin page
  49. How to change custom post type pemalink Hierarcy
  50. How to stop activating a plugin and show admin notice when dependent plugins minimum version is not met
  51. Fixing WordPress’s Bug (failed to send buffer of zlib output compression) results in “White Screen of Death”
  52. Disable woocommerce cookies and delete cart data automatically
  53. How can I make my metabox appear?
  54. Consolidate plugin functionality into a theme
  55. qTranslate remove default directory from link
  56. Count posts by type including drafts and pending posts
  57. Redirect to another page using contact form 7? [closed]
  58. List the authors that have written posts in a category
  59. Separate database for a wordpress plugin
  60. WordPress Multisite: Programmatically Activate / Deactivate a Plugin of a Specific Blog
  61. remove all submenus from plugin
  62. Hook for page Request?
  63. composer not working on my plugin when i upload it to my website
  64. What is the WordPress approach to custom data?
  65. WordPress Fatal Errors [closed]
  66. Possible?? Pull Plugin Property Data to a Theme’s Custom Post Type
  67. How to render a template file using shortcode inside a plugin
  68. How to rewrite URL and get the values?
  69. Delete data from custom table when deleting a post
  70. Disable plugin visibility at the plugin directory
  71. Plugin is creating posts twice
  72. How to deactivate my plugin upon deactivation of NextGen
  73. Code for unique user visit count on every page WordPress
  74. Widgets are not displaying in the admin panel
  75. How to overwrite the category template in a plugin
  76. Content-Security-Policy implementation with WordPress W3Total Cache plugin installed
  77. Custom Plugin: How to Include Install Buttons of other 3rd Party Plugins?
  78. show wc_add notices on particular page in woo commerce custom plugin development
  79. How to change the width of certain paragraph or header blocks?
  80. How to write different events from different functions in my file to a log file in WordPress
  81. Create a form and have custom menu display based on user answers?
  82. How to make a plugin api route have permission?
  83. Why my multisite is this slow? (stats inside)
  84. Modify Plugin PHP Class in Child Theme – Correct Method
  85. Problem with conditional woocommerce custom checkout field
  86. mailjet plugin – extend functionnalities and reuse api
  87. trying to create simple plugin to filter categories from all authors
  88. Change wp_mail SMTP settings for each E-Mail
  89. Proper Failure of Plugin Activation
  90. WordPress Thumbnail add action if no thumbnail
  91. How can I add the custom taxonomy categories to the posts and pages?
  92. Creating fields in the database
  93. Pass strings to plugin function [closed]
  94. How to create a page template using custom plugin
  95. WordPress 3,5 and Jquery version
  96. contact form 7 captcha support anyother captcha plugin? [closed]
  97. wordpress illegal string offset ‘parameter’ error
  98. How can I make my plugin detect if a certain theme is active?
  99. Plugin Block at the backend of every page or post
  100. Pulsing circle before the post title (Breaking news flash)
techhipbettruvabetnorabahisbahis forumuedueduedusedueduedusedueduedusedus