Press This in 4.9

In WordPress 4.9, Press This has found a new home as a “canonical” plugin.

Proposed in #41689 and committed in r41584, Press This and the supporting functions are no longer in CoreCore Core is the set of software required to run WordPress. The Core Development Team builds WordPress. at all. This is notably different than the Link Manager deprecation, which left all of the code in Core but deactivated behind a filterFilter Filters are one of the two types of Hooks https://codex.wordpress.org/Plugin_API/Hooks. They provide a way for functions to modify data of other functions. They are the counterpart to Actions. Unlike Actions, filters are meant to work in an isolated manner, and should never have side effects such as affecting global variables and output.. If you are extending the WP_Press_This class, you will need to update your pluginPlugin A plugin is a piece of software containing a group of functions that can be added to a WordPress website. They can extend functionality or add new features to your WordPress websites. WordPress plugins are written in the PHP programming language and integrate seamlessly with WordPress. These can be free in the WordPress.org Plugin Directory https://wordpress.org/plugins/ or can be cost-based plugin from a third-party or theme as it is no longer present in Core.

When someone visits wp-adminadmin (and super admin)/press-this.php, they are given a prompt to install the new plugin or to notify their administrator to install it:

If installing it through the prompt above, the activation flow will return them to Press This:

If you are extending Press This or are depending on functionality from it, you can see how to check for plugin availability via 4.9’s wp-admin/press-this.php and please comment on #37938 discussing if some of the parsing functionality of Press This would be beneficial ported back into Core.

In the new plugin, older bookmarklets will no longer function and this feature is discontinued. Usage of bookmarklets across the web has decreased significantly and bad actors attempting to trick users to preform unsavory actions increased over the years. Coupled with advancing toward a new editing in experience in Core, we decided it was a suitable time to make these changes in one swift move.

Continued development of Press This will happen at https://github.com/WordPress/press-this/ and I hope those who like the streamline editing experience will continue to contribute. Short-term goals include switching to the REST API instead of admin-ajax and tweaking the current experience.

#4-9, #dev-notes