From 1615506c5b1add264e550244a7da5b02cad67855 Mon Sep 17 00:00:00 2001
From: Tetrakern <26898880+Tetrakern@users.noreply.github.com>
Date: Sun, 13 Oct 2024 10:14:34 +0200
Subject: [PATCH] Add fictioneer_filter_body_attributes filter

---
 FILTERS.md | 27 +++++++++++++++++++++++++++
 header.php |  3 +++
 2 files changed, 30 insertions(+)

diff --git a/FILTERS.md b/FILTERS.md
index 44b4cd15..512dec8b 100644
--- a/FILTERS.md
+++ b/FILTERS.md
@@ -115,6 +115,33 @@ Filters the intermediate output array in the `_article-cards.php` partial before
 
 ---
 
+### `apply_filters( 'fictioneer_filter_body_attributes', $attributes, $args )`
+Filters the intermediate output array of additional body attributes (except `class` which is handled by `body_class()`) before it is mapped, escaped, imploded, and rendered in the `header.php` template.
+
+**$attributes:**
+* `data-post-id` (int) – Current post ID (or -1 if null).
+* `data-story-id` (int|null) – Current story ID (if any). Unsafe.
+
+**$args:**
+* `post_id` (int|null) – Current post ID. Unsafe.
+* `post_type` (string|null) – Current post type. Unsafe.
+* `story_id` (int|null) – Current story ID (if chapter). Unsafe.
+* `header_image_url` (string|boolean) – URL of the filtered header image or false.
+* `header_image_source` (string) – Source of the header image. Either `'default'`, `'post'`, or `'story'`.
+* `header_args` (array) – Arguments passed to the header.php partial.
+
+**Example:**
+```php
+function child_add_body_attributes( $attributes ) {
+  $attributes['data-permalink'] = get_permalink();
+
+  return $attributes;
+}
+add_filter( 'fictioneer_filter_body_attributes', 'child_add_body_attributes' );
+```
+
+---
+
 ### `apply_filters( 'fictioneer_filter_breadcrumbs_array', $breadcrumbs, $args )`
 Filters the array of breadcrumb tuples inside the `fictioneer_get_breadcrumbs( $args )` function before the HTML is build.
 
diff --git a/header.php b/header.php
index 27486bb9..cf1efbf9 100644
--- a/header.php
+++ b/header.php
@@ -98,6 +98,9 @@ if ( $story_id ) {
   $body_attributes['data-story-id'] = $story_id;
 }
 
+$body_attributes = apply_filters( 'fictioneer_filter_body_attributes', $body_attributes, $action_args );
+unset( $body_attributes['class'] ); // Prevent mistakes
+
 $body_attributes = array_map(
   function ( $key, $value ) { return $key . '="' . esc_attr( $value ) . '"'; },
   array_keys( $body_attributes ),