WordPress Release: 3.9.0

TL;DR

WordPress 3.9 "Smith" introduces a completely redesigned visual editor experience with improved media management, live widget previews in the customizer, and a new theme browsing experience. This release focuses on making content creation more intuitive and enjoyable while improving the overall user experience.

Highlight of the Release

• Completely redesigned visual editor based on TinyMCE 4.0
• Drag and drop image uploads directly into the editor
• Live widget previews in the customizer
• Improved media management with audio/video playlists
• Enhanced theme browsing experience

Migration Guide

TinyMCE 4.0 Migration Notes

If you've built custom TinyMCE plugins, you'll need to update them for compatibility with TinyMCE 4.0. Key changes include:

• The plugin architecture has changed significantly
• Many API methods have been renamed or restructured
• The UI components have been completely redesigned

If your plugin uses the 'wpdialogs' plugin but doesn't enqueue wpdialog.js, you'll now see an error in the console. Make sure to properly enqueue all required scripts.

Widget Customizer Integration

If your widgets use custom scripts and styles, they should now work in the Customizer as WordPress 3.9 adds support for:

• admin_enqueue_scripts
• admin_print_scripts and admin_print_scripts-widgets.php
• admin_print_styles and admin_print_styles-widgets.php
• admin_print_footer_scripts and admin_footer-widgets.php

For widgets that use caching, check the new WP_Widget::is_preview() method to determine if the widget is being rendered in the Customizer preview to prevent leaking preview data into your cache.

Upgrade Recommendations

WordPress 3.9 is a major update that introduces significant improvements to the content editing experience and customizer functionality. We recommend all users upgrade to take advantage of these improvements.

Before upgrading:

1. Back up your website files and database
2. Test your plugins and theme in a staging environment if possible
3. Update all plugins and themes to their latest versions

Special considerations:

• If you've developed custom TinyMCE plugins, they may need updates to work with TinyMCE 4.0
• Custom widgets that use caching should be updated to use the new is_preview() method
• Theme developers should test HTML5 gallery output as line breaks have been removed

This update is particularly beneficial for content creators and site administrators who will immediately benefit from the improved editing experience and customizer enhancements.

Bug Fixes

• Fixed an issue where MediaElement.js could enter an infinite loop
• Fixed cookie handling for GET requests where caching/proxies may intercept test cookies
• Fixed pingback IP forwarding during pingback verification
• Fixed issues with widget form updates in the customizer
• Fixed gallery rendering in HTML5 themes by removing unnecessary line breaks
• Fixed issues with image cropping in the image editor
• Fixed RTL layout issues in the themes screen and editor
• Fixed issues with TinyMCE views in IE7 and IE8
• Fixed issues with the media library loading spinner appearing multiple times
• Fixed issues with widget filtering in the customizer
• Fixed issues with header image ordering in the customizer
• Fixed issues with Quick Draft textarea auto-resizing in IE8 (prevented crashes)
• Fixed issues with taxonomy quick edit list alignment in RTL mode

New Features

Improved Visual Editor

• TinyMCE 4.0: Complete redesign of the visual editor with a cleaner interface
• Drag and Drop Images: Upload images by dragging them directly into the editor
• Improved Image Editing: Edit images directly in the editor with a new modal interface
• Better Word Pasting: Improved handling of content pasted from Microsoft Word

Media Enhancements

• Audio/Video Playlists: Create and manage playlists for audio and video files
• Media Metadata: Edit metadata for audio files directly from the attachment details screen
• Responsive Media Elements: Better handling of audio and video elements on mobile devices

Customizer Improvements

• Live Widget Previews: Preview widget changes in real-time before publishing
• Improved Header Image Management: Better interface for managing header images
• Widget Accessibility: Improved keyboard navigation and screen reader support for widgets

Theme Experience

• Enhanced Theme Browser: Redesigned theme browsing interface with better filtering options
• Feature Filters: Find themes based on specific features like responsive layout or custom colors
• Improved Theme Preview: Better theme preview experience with keyboard navigation

Security Updates

• Hardened HMAC verification for improved security
• Fixed potential security issues with pingback verification by properly forwarding IP information

Performance Improvements

• Improved media library performance with better handling of loading indicators
• Optimized theme browsing experience with more efficient API requests
• Improved editor performance with updated TinyMCE 4.0
• Prevented duplicate uploads of album art when processing multiple audio files from the same album
• Added throttling when searching with AJAX in the link dialog to reduce server load
• Improved handling of large image cropping in the header customizer
• Better resource management for MediaElement players to prevent memory leaks

Impact Summary

WordPress 3.9 "Smith" represents a significant evolution in WordPress's content creation experience. The completely redesigned visual editor based on TinyMCE 4.0 makes writing and editing content more intuitive, with improved image handling, better paste support from Word, and drag-and-drop media uploads.

The customizer receives major enhancements with live widget previews, allowing users to make changes to widgets and see the results in real-time before publishing. This dramatically improves the site customization workflow, reducing the need for trial-and-error adjustments.

Media management sees substantial improvements with the introduction of audio and video playlists, better metadata handling, and responsive media elements that work well across devices. The theme browsing experience has been completely redesigned with better filtering options and previews.

For developers, WordPress 3.9 includes updated libraries (TinyMCE 4.0, MediaElement.js 2.14.2), new hooks for media and editor customization, and improved widget APIs. The release also includes numerous bug fixes, performance improvements, and security enhancements.

Overall, WordPress 3.9 delivers a more polished, intuitive content creation experience while maintaining backward compatibility and improving performance across the platform.