Better guide users when deleting other users in single- and multisites

src/js/_enqueues/admin/common.js

@@ -2356,3 +2356,59 @@ $( function( $ ) {
 	// Expose public methods.
 	return pub;
 })();
+
+/**
+ * Disable the submit button until all users radio buttons are checked.
+ *
+ * @since 7.0.0
+ */
+(function(){
+	const usersForm = document.querySelector( '.users-php .delete-and-reassign-users-form' );
+
+	// Check if the form exists and contains any radio buttons.
+	if ( ! usersForm || ! usersForm.querySelector( 'input[type="radio"]' ) ) {
+		return;
+	}
+
+	const submitBtn = usersForm.querySelector( 'input[type="submit"]' );
+
+	// Disable the submit button until all users radio buttons are checked.
+	submitBtn.disabled = true;
+
+	// Listen for changes on any radio input in the form.
+	usersForm.addEventListener('change', function() {
+ 		if ( ! usersForm.checkValidity() ) {
+			submitBtn.disabled = true;
+			return;
+		}
+
+		// Check all radio groups for validity.
+		let allValid = true;
+		const radioGroups = usersForm.querySelectorAll( 'fieldset ul' );
+		radioGroups.forEach( function( radioGroup ) {
+			const radios = radioGroup.querySelectorAll( 'input[type="radio"]' );
+			let checkedRadio = null;
+			radios.forEach( function( radio ) {
+				if ( radio.checked ) {
+					checkedRadio = radio;
+				}
+			});
+
+			if ( checkedRadio && checkedRadio.value === 'reassign' ) {
+				const select = radioGroup.querySelector( 'select' );
+				if ( select && select.value === '-1' ) {
+					allValid = false;
+				}
+			}
+		});
+
+		submitBtn.disabled = !allValid;
+	});
+
+	usersForm.querySelectorAll( 'select' ).forEach( function( selectElement ) {
+		selectElement.addEventListener( 'change', function( e ) {
+			const radio = e.target.closest( 'li' ).querySelector( 'input[type="radio"]' );
+			radio.checked = e.target.value !== '-1';
+		});
+	});
+})();

src/wp-admin/includes/deprecated.php

@@ -1589,3 +1589,14 @@ function image_attachment_fields_to_save( $post, $attachment ) {
 
 	return $post;
 }
+
+/**
+ * Was used to add JavaScript to the delete users form.
+ *
+ * @since 3.5.0
+ * @deprecated 7.0.0
+ * @access private
+ */
+function delete_users_add_js() {
+	_deprecated_function( __FUNCTION__, '7.0.0' );
+}

src/wp-admin/includes/ms.php

@@ -856,30 +856,31 @@ function _thickbox_path_admin_subfolder() {
  * @return bool
  */
 function confirm_delete_users( $users ) {
+	global $wpdb;
+
 	$current_user = wp_get_current_user();
 	if ( ! is_array( $users ) || empty( $users ) ) {
 		return false;
 	}
+
 	?>
-	<h1><?php esc_html_e( 'Users' ); ?></h1>
+	<h1><?php esc_html_e( 'Delete Users' ); ?></h1>
 
 	<?php if ( 1 === count( $users ) ) : ?>
 		<p><?php _e( 'You have chosen to delete the user from all networks and sites.' ); ?></p>
 	<?php else : ?>
 		<p><?php _e( 'You have chosen to delete the following users from all networks and sites.' ); ?></p>
 	<?php endif; ?>
 
-	<form action="users.php?action=dodelete" method="post">
+	<form action="users.php?action=dodelete" method="post" class="delete-and-reassign-users-form">
 	<input type="hidden" name="dodelete" />
 	<?php
 	wp_nonce_field( 'ms-users-delete' );
 	$site_admins = get_super_admins();
-	$admin_out   = '<option value="' . esc_attr( $current_user->ID ) . '">' . $current_user->user_login . '</option>';
 	?>
 	<table class="form-table" role="presentation">
 	<?php
-	$allusers = (array) $_POST['allusers'];
-	foreach ( $allusers as $user_id ) {
+	foreach ( $users as $user_id ) {
 		if ( '' !== $user_id && '0' !== $user_id ) {
 			$delete_user = get_userdata( $user_id );
 
@@ -902,6 +903,7 @@ function confirm_delete_users( $users ) {
 					)
 				);
 			}
+
 			?>
 			<tr>
 				<th scope="row"><?php echo $delete_user->user_login; ?>
@@ -912,60 +914,101 @@ function confirm_delete_users( $users ) {
 
 			if ( ! empty( $blogs ) ) {
 				?>
-				<td><fieldset><p><legend>
+				<td><fieldset><legend>
 				<?php
 				printf(
 					/* translators: %s: User login. */
-					__( 'What should be done with content owned by %s?' ),
-					'<em>' . $delete_user->user_login . '</em>'
+					__( '%s: What should be done with the content owned by this user?' ),
+					$delete_user->user_login
 				);
 				?>
-				</legend></p>
+				</legend>
 				<?php
 				foreach ( (array) $blogs as $key => $details ) {
 					$blog_users = get_users(
 						array(
 							'blog_id' => $details->userblog_id,
-							'fields'  => array( 'ID', 'user_login' ),
+							'fields'  => array( 'ID' ),
+							'exclude' => $users,
 						)
 					);
 
+					$blog_users = wp_list_pluck( $blog_users, 'ID' );
+
 					if ( is_array( $blog_users ) && ! empty( $blog_users ) ) {
-						$user_site     = "<a href='" . esc_url( get_home_url( $details->userblog_id ) ) . "'>{$details->blogname}</a>";
-						$user_dropdown = '<label for="reassign_user" class="screen-reader-text">' .
-								/* translators: Hidden accessibility text. */
-								__( 'Select a user' ) .
-							'</label>';
-						$user_dropdown .= "<select name='blog[$user_id][$key]' id='reassign_user'>";
-						$user_list      = '';
-
-						foreach ( $blog_users as $user ) {
-							if ( ! in_array( (int) $user->ID, $allusers, true ) ) {
-								$user_list .= "<option value='{$user->ID}'>{$user->user_login}</option>";
+						$user_site = "<a href='" . esc_url( get_home_url( $details->userblog_id ) ) . "'>{$details->blogname}</a>";
+						switch_to_blog( $details->userblog_id );
+						/* This filter is documented in wp-admin/users.php */
+						$user_has_content = (bool) apply_filters( 'users_have_additional_content', false, array( $delete_user->ID ) );
+
+						if ( ! $user_has_content ) {
+							if ( $wpdb->get_var(
+								$wpdb->prepare(
+									"SELECT ID FROM {$wpdb->posts}
+									WHERE post_author = %d
+									LIMIT 1",
+									$delete_user->ID
+								)
+							) ) {
+								$user_has_content = true;
+							} elseif ( $wpdb->get_var(
+								$wpdb->prepare(
+									"SELECT link_id FROM {$wpdb->links}
+									WHERE link_owner = %d
+									LIMIT 1",
+									$delete_user->ID
+								)
+							) ) {
+								$user_has_content = true;
 							}
 						}
-
-						if ( '' === $user_list ) {
-							$user_list = $admin_out;
-						}
-
-						$user_dropdown .= $user_list;
-						$user_dropdown .= "</select>\n";
-						?>
-						<ul style="list-style:none;">
-							<li>
+						restore_current_blog();
+
+						if ( ! $user_has_content ) {
+							?>
+							<p>
+							<?php
+							/* translators: %s: Link to user's site. */
+							printf( __( 'Site: %s' ), $user_site );
+							?>
+							</p>
+							<input type="hidden" id="delete_option_<?php echo esc_attr( $details->userblog_id . '_' . $delete_user->ID ); ?>" name="delete[<?php echo $details->userblog_id . '][' . $delete_user->ID; ?>]" value="delete" required />
+							<p><?php _e( 'This user does not have any content.' ); ?></p>
+							<?php
+						} else {
+							?>
+							<p>
 								<?php
 								/* translators: %s: Link to user's site. */
 								printf( __( 'Site: %s' ), $user_site );
 								?>
-							</li>
-							<li><label><input type="radio" id="delete_option0" name="delete[<?php echo $details->userblog_id . '][' . $delete_user->ID; ?>]" value="delete" checked="checked" />
-							<?php _e( 'Delete all content.' ); ?></label></li>
-							<li><label><input type="radio" id="delete_option1" name="delete[<?php echo $details->userblog_id . '][' . $delete_user->ID; ?>]" value="reassign" />
-							<?php _e( 'Attribute all content to:' ); ?></label>
-							<?php echo $user_dropdown; ?></li>
-						</ul>
-						<?php
+							</p>
+							<ul>
+								<li>
+									<input type="radio" id="delete_option_<?php echo esc_attr( $details->userblog_id . '_' . $delete_user->ID ); ?>" name="delete[<?php echo $details->userblog_id . '][' . $delete_user->ID; ?>]" value="delete" required />
+									<label for="delete_option_<?php echo esc_attr( $details->userblog_id . '_' . $delete_user->ID ); ?>"><?php _e( 'Delete all content.' ); ?></label>
+								</li>
+								<li>
+									<input type="radio" id="reassign_option_<?php echo esc_attr( $details->userblog_id . '_' . $delete_user->ID ); ?>" name="delete[<?php echo $details->userblog_id . '][' . $delete_user->ID; ?>]" value="reassign" required />
+									<label for="reassign_option_<?php echo esc_attr( $details->userblog_id . '_' . $delete_user->ID ); ?>"><?php _e( 'Attribute all content to another user.' ); ?></label>
+
+									<label for="reassign_user_<?php echo esc_attr( $details->userblog_id . '_' . $delete_user->ID ); ?>" class="screen-reader-text"><?php _e( 'Select a user to attribute the content to.' ); ?></label>
+									<?php
+									wp_dropdown_users(
+										array(
+											'show_option_none' => __( 'Select a user' ),
+											'name'    => "blog[$user_id][$key]",
+											'include' => $blog_users,
+											'show'    => 'display_name_with_login',
+											'id'      => "reassign_user_{$details->userblog_id}_{$delete_user->ID}",
+										)
+									);
+									?>
+
+								</li>
+							</ul>
+							<?php
+						}
 					}
 				}
 				echo '</fieldset></td></tr>';
@@ -982,7 +1025,7 @@ function confirm_delete_users( $users ) {
 	</table>
 	<?php
 	/** This action is documented in wp-admin/users.php */
-	do_action( 'delete_user_form', $current_user, $allusers );
+	do_action( 'delete_user_form', $current_user, $users );
 
 	if ( 1 === count( $users ) ) :
 		?>
@@ -992,7 +1035,7 @@ function confirm_delete_users( $users ) {
 		<?php
 	endif;
 
-	submit_button( __( 'Confirm Deletion' ), 'primary' );
+	submit_button( __( 'Confirm Deletion' ), 'primary', 'submit', false, array( 'id' => 'confirm-users-deletion' ) );
 	?>
 	</form>
 	<?php

src/wp-admin/includes/user.php

@@ -561,26 +561,6 @@ function default_password_nag() {
 	);
 }
 
-/**
- * @since 3.5.0
- * @access private
- */
-function delete_users_add_js() {
-	?>
-<script>
-jQuery( function($) {
-	var submit = $('#submit').prop('disabled', true);
-	$('input[name="delete_option"]').one('change', function() {
-		submit.prop('disabled', false);
-	});
-	$('#reassign_user').focus( function() {
-		$('#delete_option1').prop('checked', true).trigger('change');
-	});
-} );
-</script>
-	<?php
-}
-
 /**
  * Optional SSL preference that can be turned on by hooking to the 'personal_options' action.
  *

src/wp-admin/network/users.php

@@ -56,8 +56,9 @@
 
 				$doaction     = $_POST['action'];
 				$userfunction = '';
+				$allusers     = (array) $_POST['allusers'];
 
-				foreach ( (array) $_POST['allusers'] as $user_id ) {
+				foreach ( $allusers as $user_id ) {
 					if ( ! empty( $user_id ) ) {
 						switch ( $doaction ) {
 							case 'delete':
@@ -72,7 +73,7 @@
 								require_once ABSPATH . 'wp-admin/admin-header.php';
 
 								echo '<div class="wrap">';
-								confirm_delete_users( $_POST['allusers'] );
+								confirm_delete_users( $allusers );
 								echo '</div>';
 
 								require_once ABSPATH . 'wp-admin/admin-footer.php';