Move Content::preloadTransform to ContentHandler

Update ContentTransformer to access ContentHandler::preLoadTransform through the service.
Prepare object to hold a data that required for ContentHandler::preLoadTranform params.

This is a fully backwards compatible change.
We are doing hard deprecation via MWDebug::detectDeprecatedOverride.

However, with the ContentHandler calling Content and
Content calling ContentHandler, it doesn't matter whether
callers use Content or ContentHandler. This will allow us
to naturally convert all callers.

Bug: T287157
Change-Id: I89537e1e7d24c6e15252b2b51890a0bd81ea3e6b

3 files changed, 100 insertions, 0 deletions

diff --git a/includes/content/Transform/ContentTransformer.php b/includes/content/Transform/ContentTransformer.php
index 2229f4b86ba0..01288b887021 100644
--- a/includes/content/Transform/ContentTransformer.php
+++ b/includes/content/Transform/ContentTransformer.php
@@ -45,4 +45,27 @@ class ContentTransformer {
 
 		return $contentHandler->preSaveTransform( $content, $pstParams );
 	}
+
+	/**
+	 * Returns a Content object with preload transformations applied (or $content
+	 * if no transformations apply).
+	 *
+	 * @param Content $content
+	 * @param PageReference $page
+	 * @param ParserOptions $parserOptions
+	 * @param array $params
+	 *
+	 * @return Content
+	 */
+	public function preloadTransform(
+		Content $content,
+		PageReference $page,
+		ParserOptions $parserOptions,
+		array $params = []
+	): Content {
+		$contentHandler = $this->contentHandlerFactory->getContentHandler( $content->getModel() );
+		$pltParams = new PreloadTransformParamsValue( $page, $parserOptions, $params );
+
+		return $contentHandler->preloadTransform( $content, $pltParams );
+	}
 }
diff --git a/includes/content/Transform/PreloadTransformParams.php b/includes/content/Transform/PreloadTransformParams.php
new file mode 100644
index 000000000000..92277904c663
--- /dev/null
+++ b/includes/content/Transform/PreloadTransformParams.php
@@ -0,0 +1,27 @@
+<?php
+namespace MediaWiki\Content\Transform;
+
+use MediaWiki\Page\PageReference;
+use ParserOptions;
+
+/**
+ * @since 1.37
+ * An interface to hold pre-load transform params.
+ */
+interface PreloadTransformParams {
+
+	/**
+	 * @return PageReference
+	 */
+	public function getPage(): PageReference;
+
+	/**
+	 * @return array
+	 */
+	public function getParams(): array;
+
+	/**
+	 * @return ParserOptions
+	 */
+	public function getParserOptions(): ParserOptions;
+}
diff --git a/includes/content/Transform/PreloadTransformParamsValue.php b/includes/content/Transform/PreloadTransformParamsValue.php
new file mode 100644
index 000000000000..f1f1fbeb2be2
--- /dev/null
+++ b/includes/content/Transform/PreloadTransformParamsValue.php
@@ -0,0 +1,50 @@
+<?php
+namespace MediaWiki\Content\Transform;
+
+use MediaWiki\Page\PageReference;
+use ParserOptions;
+
+/**
+ * @internal
+ * An object to hold preload transform params.
+ */
+class PreloadTransformParamsValue implements PreloadTransformParams {
+	/** @var PageReference */
+	private $page;
+
+	/** @var array */
+	private $params;
+
+	/** @var ParserOptions */
+	private $parserOptions;
+
+	public function __construct( PageReference $page, ParserOptions $parserOptions, array $params = [] ) {
+		$this->page = $page;
+		$this->parserOptions = $parserOptions;
+		$this->params = $params;
+	}
+
+	/**
+	 *
+	 * @return PageReference
+	 */
+	public function getPage(): PageReference {
+		return $this->page;
+	}
+
+	/**
+	 *
+	 * @return array
+	 */
+	public function getParams(): array {
+		return $this->params;
+	}
+
+	/**
+	 *
+	 * @return ParserOptions
+	 */
+	public function getParserOptions(): ParserOptions {
+		return $this->parserOptions;
+	}
+}