Howdy. The 4.7 release cycle has been a chance to build on some of the work from the last couple releases in multisite. If you’d like more detail, check out the full list of multisite focused changes in this release.
get_blog_details() replaced with get_site()
A lot of progress has been made over the last few releases to get things in place for this transition. Now that
WP_Network objects exist and are accessible with functions like
get_network(), they can be implemented throughout core.
In WordPress 4.7,
get_blog_details() was replaced throughout core code with the modern
get_site(). The roadmap for this includes deprecating
get_blog_details() in WordPress 4.8, so take this cycle as a chance to move your code in that direction.
get_site() is often a direct replacement, though
get_sites() can also be used to query for sites when an ID is not available.
See #37102 for details on this change.
blog_details filter deprecated
In combination with the decision to stop using
get_blog_details() throughout core, the (not widely used)
blog_details filter has been deprecated. It has been added to
get_site() to provide backward compatibility with the above change and will fire with a deprecation notice. Plugin code should use the
site_details filter instead. See #38491 for details on this change.
_network_option actions and filters get $network_id
$network_id associated with the use of a
_network_option() function is now passed to the filters and actions that fire within. This provides granular control that was not available when first introduced. See #38319, #38320, #38321, and #38322 for details on this change.
It is now recommended that
get_network() is used instead. See #37553 for this change.