Add before/after hooks to override output of wp_widget_control()

[westonruter]

As part of the widgets improvements being worked on for core, we need to override the default output of wp_widget_control(). One way to do this is to add a before/after actions around the output generated by the function:

src/wp-admin/includes/widgets.php

@@ -188 +188 @@
         $widget_title = esc_html( strip_tags( $sidebar_args['widget_name'] ) );
         $has_form = 'noform';
 
+        do_action( 'temp_wp_widget_control_before', $sidebar_args );
         echo $sidebar_args['before_widget']; ?>
         <div class="widget-top">
         <div class="widget-title-action">
@@ -237 +238 @@
         </div>
 <?php
         echo $sidebar_args['after_widget'];
+        do_action( 'temp_wp_widget_control_after', $sidebar_args, $has_form !== 'noform' );
         return $sidebar_args;
 }

Such hooks seem useful on a permanent basis as well, so perhaps the temp_ prefix can be dropped to begin with.

See related discussion on IRC (up until the end of the day): ​https://irclogs.wordpress.org/chanlog.php?channel=wordpress-ui&day=2013-12-16&sort=asc#m144514

Related to #25368

[SergeyBiryukov]

Can we just pass $has_form rather than $has_form !== 'noform' as the last argument to wp_widget_control_after?

[westonruter]

Pass $has_form variable into action as-is, and remove temp_ prefix

[SergeyBiryukov]

In 26865:

Add temporary hooks for the widgets feature team to wp_widget_control().

props westonruter.
see #26661.

[SergeyBiryukov]

In 26866:

Add comments for temporary hooks. see #26661.

[SergeyBiryukov]

On second thought, 'noform' !== $has_form seems to make sense, so I decided to leave it as is.

We'd need to document the new hooks if they are going to stay.

[westonruter]

Remove temp_ prefixes and add docs to new action hooks wp_widget_control_before and wp_widget_control_after

[westonruter]

Applying some more hook docs improvements gleaned from DrewAPicture in #25368

[westonruter]

It turns out that we actually didn't need this, since the widget icons are being supplied via CSS as dashicons instead of as inline image elements.

[SergeyBiryukov]

Do we still need temporary hooks added in [26865]? If not, let's remove them.

[westonruter]

Replying to SergeyBiryukov:

Do we still need temporary hooks added in [26865]? If not, let's remove them.

They can be removed, yes, unless @shaunandrews objects.

[SergeyBiryukov]

In 27324:

Remove temporary hooks added in [26865].

fixes #26661.