WordPress Hooks

General

• David Hayes. WordPress Hooks, Actions, and Filters: What They Do and How They Work. wpshout, 2018. **
  • A great introductory article, especially useful in the clarity and consistency it brings in describing key terms. Highly recommend.
• Agbonghama Collins. Demystifying the WordPress Hook System. SitePoint, 2016.
  • A good overview article.
• Agbonghama Collins. Alternative Ways of Triggering Events in WordPress. SitePoint, 2016.
• Agbonghama Collins. Understanding Namespaces in the WordPress Hook System. SitePoint, 2016.
• Daniel Pataki. A Quick (and in-Depth) Guide to WordPress Hooks. wpmudev, 2015.
• Daniel Pataki. Understanding WordPress Hooks: Knowing What to Use Where. wpmudev, 2015.
• Fred Meyer. A Complete Introduction to the WordPress Hooks System. wpshout, 2016.
• Rachel McCollin. WordPress Actions and Filters: What the Difference? envatotuts, 2016.
• Jeremy Pryon. Getting Started with WordPress Hooks. webdevstudios, 2015.
• Nick Schaferhoff. The Complete Newbie Guide to WordPress Hooks. Torque, 2015.
• David Hayers. The WordPress Event System: Understanding Hooks in the Broader Programming Context. wpshout, 2016.
• Thomas Maier. Useful Tips to Get Started with WordPress Hooks. Smashing Magazine, 2016.
• Simon Codrington. Digging Deeper into WordPress Hooks and Filters. sitepoint, 2016.
• Tom McFarlin. Adding Custom Hooks in WordPress Series. envatotuts, 2016.
  • Custom Actions
  • Custom Filters
• Tom McFarlin. Using WordPress for Web Application Development: Understanding Events, Actions, and Filters. envatotuts+, 2013.
• Zach Owen. Debugging WordPress Core: Actions and Filters. webdevstudios, 2019.
• Gennady Kovshenin. Inside WordPress Actions and Filters. Smashing Magazine, 2012.
• Tom McFarlin. The Beginner’s Guide to WordPress Actions and Filters. envatotuts, 2012.
• David Hayes. Where and How to Use WordPress Hooks in Objects. wpshout, 2018.
• Rakhitha Nimesh. WordPress Initialization Hooks: Benefits and Common Mistakes. envatotuts, 2014.
• Daniel Pataki. The Definitive Guide to WordPress Hooks. Smashing Magazine, 2011.

Reference

• Adam R. Brown. WordPress Hooks Database.
  • Lists all hooks, both filters and actions, notes what version of WP the hook was initially added, and if the hook has been deprecated.
• Hookr – The WordPress Hook/API Index.

Creating Custom Hooks

• Daniel Pataki. WordPress Hooks: Beginner’s Guide to Adding Your Own Hooks. codeinwp, 2018.

Regular Expressions in Hooks

• How to Filter and Replace HTML in the WordPress Content Loop. Inbound Horizons, 2017.
  • I haven’t been able to find a lot of articles on this topic, this is one of the first. It shows how to accomplish this using PHP and regex.

Other Specific

• Pippin Williamson. Using Filters to Alter HTML Output. 2012.
  • Examples show how to strip tags and how to add a wrapper around existing HTML.

Action Hooks

• Andreas Hecht. WordPress: Modern Theme Development with Action Hooks. Noupe, 2017.
• Baris Unver. Fifty Actions of WordPress – 50 Examples. envatotuts, 2014.
  • Fifty Actions of WordPress – An Introduction.
  • Fifty Actions of WordPress – 50 Examples (1 to 10). – Covers init, send_headers, after_switch_theme, manage_posts_custom_column, admin_head, wp_footer, wp_enqueue_script, admin_notices, widgets_init, delete_user.
  • Fifty Actions of WordPress – 50 Examples (11 to 20) – Covers wp_default_styles, get_footer, admin_init, wp_authenticate, login_form, admin_menu, wp_admin_head-(page_name), wp_before_admin_bar_render, profile_update.
  • Fifty Actions of WordPress – 50 Examples (21 to 30) – Covers pre_get_posts, transition_post_status, admin_enqueue_scripts, save_post, add_meta_boxes, activity_box_end, wp_meta, wp_dashboard_setup, wp_set_current_user, plugins_loaded.
  • Fifty Actions of WordPress – 50 Examples (31 to 40) – Covers wp_default_scripts, wp_head, after_setup_theme, manage_media_custom_column, transition_comment_status, template_redirect, do_feed, show_admin_bar, wp_list_categories, pre_get_search_form.
  • Fifty Actions of WordPress – 50 Examples (41 to 50) – Covers admin_head-plugin, pre_ping, get_header, login_head, admin_footer, login_enqueue_scripts, manage_users_custom_column, activated_plugin, admin_color_scheme_picker, wp_logout.
• Rakhitha Nimesh. Customizing WordPress Themes with Action Hooks. sitepoint, 2013.
• Pippin Williamson. Quick Introduction to Action Hooks. 2012.

Filter Hooks

• Raelene Morey. WordPress Filters Cheat Sheet. Design Bombs, 2018.
• Baris Unver. 50 Filters of WordPress Series. envatotuts+, 2014.**
  • 1. An Introduction to Filters.
  • 2. The First 10 Filters.
    • Covers login_errors, comment_post_redirect, wp_safe_redirect, body_class, locale, sanitize_user, the_content, the_password_form, the_terms, wp_mail_from,
  • 3. Filters 11-20.
    • Covers gettext, sanitize_title, no_texturize_shorttcodes, pre_comment_approve, enable_post_by_email_configuration, wp_title, preprocess_comment, login_redirect, creating a custom filter, the_editor_content.
  • 4. Filters 21-30.
    • Covers posts_search, wp_editor_set_quality, widget_text, the_content_feed, mce_buttons, list_terms_exclusions, image_sizes_names_choose, excerpt_more, manage_post_columns, user_contactmethods.
  • 5. Filters 31-40.
    • use_default_gallery_style, wp_get_attachment_url, wp_mail_content_type, pre_comment_user_ip, wp_revisions_to_keep, img_caption_shortcode, post_class, attachment_fields_to_edit, excerpt_length, bulk_actions--edit-post.
  • 6. Filters 41-50.
    • script_loader_src, admin_post_thumbnail_html, comment_flood_filter, dashboard_glance_items, login_message, bulk_post_updated_messages, widget_categories_args, registration_redirect, comment_form_default_fields, upload_mimes.
  • 7. Series Finale.
• Tom McFarlin. Using Custom Filters with Shortcodes. 2019.
  • Really straightforward example and explanation of creating a shortcode that uses a filter.
• Tom McFarlin. Properly Filtering Post Content (And Understanding apply_filters). 2017.
  • Explains the WordPress way of updating the_content using filters.
• Tom McFarlin. Adding Custom Hooks in WordPress: Custom Filters. envatotuts, 2016.
• Simon Codrington. Customized WordPress Administration Filters. sitepoint, 2014.
• Daniel Pataki. How to Add Post Filters to Your WordPress Site. wpmudev, 2015.
• Pippin Williamson. A Quick Introduction to Using Filters. 2012.
• Pippin Williamson. Using Filters to Alter HTML Output. 2012.
• Pippin Williamson. Playing Nice with the “the_content” Filter. 2012.
  • Helpful in understanding best practices to ensure that the content that is getting filtered is actually what is intended.