Directly link to a help tab. (#1598)

* Directly link to a help tab.

This PR allows you to directly link to help tabs. The idea is to use it for the Onboarding as part of a launchpad.

* phpcs fixes

* Add changelog

* use `{$hook_suffix}` action

* use vanilla js

* add allowlist (limited to activitypub help tabs)

* fix phpcs issues

* Backslashit

* Increase selector specificity

Only clicks anchors that are direct descendants of `hash`, where the href attribute begins with `#tab-panel-`.

---------

Co-authored-by: Konstantin Obenland <[email protected]>

Author: pfefferle

.github/changelog/1598-from-description

@@ -0,0 +1,4 @@
+Significance: minor
+Type: added
+
+Enable direct linking to Help Tabs.

includes/wp-admin/class-admin.php

@@ -60,6 +60,8 @@ public static function init() {
 		if ( site_supports_blocks() ) {
 			\add_action( 'tool_box', array( self::class, 'tool_box' ) );
 		}
+
+		\add_action( 'admin_print_footer_scripts-settings_page_activitypub', array( self::class, 'open_help_tab' ) );
 	}
 
 	/**
@@ -609,4 +611,38 @@ public static function plugin_update_message( $data, $update ) {
 	public static function tool_box() {
 		\load_template( ACTIVITYPUB_PLUGIN_DIR . 'templates/toolbox.php' );
 	}
+
+	/**
+	 * Open the help tab.
+	 *
+	 * This function is used to open the help tab,
+	 * it is triggered by the hash in the URL.
+	 */
+	public static function open_help_tab() {
+		// get all tabs registered for the ActivityPub settings page.
+		$tabs = \get_current_screen()->get_help_tabs();
+		$ids  = \array_values( \wp_list_pluck( $tabs, 'id' ) );
+		$ids  = \array_map(
+			function ( $id ) {
+				return '#tab-link-' . $id;
+			},
+			$ids
+		);
+		?>
+		<script type="text/javascript">
+		document.addEventListener('DOMContentLoaded', function() {
+			// add allowed ids to the hash.
+			const hash = window.location.hash;
+			const allowed_ids = <?php echo \wp_json_encode( $ids ); ?>;
+			if (allowed_ids.includes(hash)) {
+				// Small delay to ensure the help tab is loaded.
+				setTimeout(function() {
+					document.getElementById('contextual-help-link').click();
+					document.querySelector(hash + ' > a[href^="#tab-panel-"]').click();
+				}, 500);
+			}
+		});
+		</script>
+		<?php
+	}
 }