Includes: Added back support for parse theme event

Managed to do this in an API-compatible way although resuling output may
differ due to new dom handling in general, although user content is used
inline to remain as comptable as possible.

app/Entities/Tools/PageContent.php

@@ -5,10 +5,13 @@ namespace BookStack\Entities\Tools;
 use BookStack\Entities\Models\Page;
 use BookStack\Entities\Tools\Markdown\MarkdownToHtml;
 use BookStack\Exceptions\ImageUploadException;
+use BookStack\Facades\Theme;
+use BookStack\Theming\ThemeEvents;
 use BookStack\Uploads\ImageRepo;
 use BookStack\Uploads\ImageService;
 use BookStack\Util\HtmlContentFilter;
 use BookStack\Util\HtmlDocument;
+use Closure;
 use DOMElement;
 use DOMNode;
 use DOMNodeList;
@@ -280,18 +283,11 @@ class PageContent
         }
 
         $doc = new HtmlDocument($html);
-
-        $contentProvider = function (int $id) use ($blankIncludes) {
-            if ($blankIncludes) {
-                return '';
-            }
-            return Page::visible()->find($id)->html ?? '';
-        };
-
+        $contentProvider = $this->getContentProviderClosure($blankIncludes);
         $parser = new PageIncludeParser($doc, $contentProvider);
-        $nodesAdded = 1;
 
-        for ($includeDepth = 0; $includeDepth < 1 && $nodesAdded !== 0; $includeDepth++) {
+        $nodesAdded = 1;
+        for ($includeDepth = 0; $includeDepth < 3 && $nodesAdded !== 0; $includeDepth++) {
             $nodesAdded = $parser->parse();
         }
 
@@ -308,6 +304,39 @@ class PageContent
         return $doc->getBodyInnerHtml();
     }
 
+    /**
+     * Get the closure used to fetch content for page includes.
+     */
+    protected function getContentProviderClosure(bool $blankIncludes): Closure
+    {
+        $contextPage = $this->page;
+
+        return function (PageIncludeTag $tag) use ($blankIncludes, $contextPage): PageIncludeContent {
+            if ($blankIncludes) {
+                return PageIncludeContent::fromHtmlAndTag('', $tag);
+            }
+
+            $matchedPage = Page::visible()->find($tag->getPageId());
+            $content = PageIncludeContent::fromHtmlAndTag($matchedPage->html ?? '', $tag);
+
+            if (Theme::hasListeners(ThemeEvents::PAGE_INCLUDE_PARSE)) {
+                $themeReplacement = Theme::dispatch(
+                    ThemeEvents::PAGE_INCLUDE_PARSE,
+                    $tag->tagContent,
+                    $content->toHtml(),
+                    clone $contextPage,
+                    $matchedPage ? (clone $matchedPage) : null,
+                );
+
+                if ($themeReplacement !== null) {
+                    $content = PageIncludeContent::fromInlineHtml(strval($themeReplacement));
+                }
+            }
+
+            return $content;
+        };
+    }
+
     /**
      * Parse the headers on the page to get a navigation menu.
      */

app/Entities/Tools/PageIncludeContent.php

@@ -10,47 +10,53 @@ class PageIncludeContent
     protected static array $topLevelTags = ['table', 'ul', 'ol', 'pre'];
 
     /**
-     * @var DOMNode[]
+     * @param DOMNode[] $contents
+     * @param bool $isInline
      */
-    protected array $contents = [];
-
-    protected bool $isTopLevel = false;
-
     public function __construct(
-        string $html,
-        PageIncludeTag $tag,
+        protected array $contents,
+        protected bool $isInline,
     ) {
-        $this->parseHtml($html, $tag);
     }
 
-    protected function parseHtml(string $html, PageIncludeTag $tag): void
+    public static function fromHtmlAndTag(string $html, PageIncludeTag $tag): self
     {
         if (empty($html)) {
-            return;
+            return new self([], true);
         }
 
         $doc = new HtmlDocument($html);
 
         $sectionId = $tag->getSectionId();
         if (!$sectionId) {
-            $this->contents = [...$doc->getBodyChildren()];
-            $this->isTopLevel = true;
-            return;
+            $contents = [...$doc->getBodyChildren()];
+            return new self($contents, false);
         }
 
         $section = $doc->getElementById($sectionId);
         if (!$section) {
-            return;
+            return new self([], true);
         }
 
         $isTopLevel = in_array(strtolower($section->nodeName), static::$topLevelTags);
-        $this->isTopLevel = $isTopLevel;
-        $this->contents = $isTopLevel ? [$section] : [...$section->childNodes];
+        $contents = $isTopLevel ? [$section] : [...$section->childNodes];
+        return new self($contents, !$isTopLevel);
+    }
+
+    public static function fromInlineHtml(string $html): self
+    {
+        if (empty($html)) {
+            return new self([], true);
+        }
+
+        $doc = new HtmlDocument($html);
+
+        return new self([...$doc->getBodyChildren()], true);
     }
 
     public function isInline(): bool
     {
-        return !$this->isTopLevel;
+        return $this->isInline;
     }
 
     public function isEmpty(): bool
@@ -65,4 +71,15 @@ class PageIncludeContent
     {
         return $this->contents;
     }
+
+    public function toHtml(): string
+    {
+        $html = '';
+
+        foreach ($this->contents as $content) {
+            $html .= $content->ownerDocument->saveHTML($content);
+        }
+
+        return $html;
+    }
 }

app/Entities/Tools/PageIncludeParser.php

@@ -19,6 +19,9 @@ class PageIncludeParser
      */
     protected array $toCleanup = [];
 
+    /**
+     * @param Closure(PageIncludeTag $tag): PageContent $pageContentForId
+     */
     public function __construct(
         protected HtmlDocument $doc,
         protected Closure $pageContentForId,
@@ -35,8 +38,8 @@ class PageIncludeParser
         $tags = $this->locateAndIsolateIncludeTags();
 
         foreach ($tags as $tag) {
-            $htmlContent = $this->pageContentForId->call($this, $tag->getPageId());
-            $content = new PageIncludeContent($htmlContent, $tag);
+            /** @var PageIncludeContent $content */
+            $content = $this->pageContentForId->call($this, $tag);
 
             if (!$content->isInline()) {
                 $parentP = $this->getParentParagraph($tag->domNode);