N°8612 inline images to base64 (#826)

core/inlineimage.class.inc.php

@@ -296,6 +296,46 @@ class InlineImage extends DBObject
 		return $sHtml;
 	}
 
+	/**
+	 * Replace <img> tags with a data-img-id attribute by the actual image in base64 representation
+	 * so that the image can be displayed even if the download URL is not accessible (e.g. in unauthenticated approval templates)
+	 *
+	 * @param string $sHtml The HTML fragment to process
+	 *
+	 * @return String The modified HTML
+	 * @since 3.2.3
+	 */
+	public static function ReplaceInlineImagesWithBase64Representation(string $sHtml): String
+	{
+		return preg_replace_callback(
+			'/<img\s+[^>]*'.static::DOM_ATTR_ID.'="(\d+)"[^>]*>/i',
+			function ($matches) {
+
+				// Extract inline image ID from the tag
+				$id = $matches[1];
+
+				try {
+					// Retrieve inline image
+					$oInline = MetaModel::GetObject(InlineImage::class, $id, true, true);
+					$oOrmDocument = $oInline->Get('contents');
+
+					// Replace src image by the base64 representation
+					$sInlineImageAsBase64 = base64_encode($oOrmDocument->GetData());
+					$sDataUri = 'data:'.$oOrmDocument->GetMimeType().';base64,'.$sInlineImageAsBase64;
+					$sImage = preg_replace('/src=["\'][^"\']+["\']/', 'src="'.$sDataUri.'"', $matches[0]);
+
+					// Remove sensitive information (the image ID and secret) from the tag
+					$sImage = preg_replace('/'.static::DOM_ATTR_ID.'="\d+"\s+'.static::DOM_ATTR_SECRET.'="\w+"/', '', $sImage);
+				} catch (Exception $e) {
+					$sImage = '<img src="" alt="'.Dict::S('UI:MissingInlineImage').'">';
+				}
+
+				return $sImage;
+			},
+			$sHtml
+		);
+	}
+
 	/**
 	 * Add an extra attribute data-img-id for images which are based on an actual InlineImage
 	 * so that we can later reconstruct the full "src" URL when needed