NEW Allow file variants with different extensions

src/FilenameParsing/AlternativeFileExtensionTrait.php

@@ -0,0 +1,80 @@
+<?php
+
+namespace SilverStripe\Assets\FilenameParsing;
+
+use SilverStripe\Core\Convert;
+
+/**
+ * This trait can be applied to a `FileIDHelper` imlementation to add the baility to encode alternative file extension.
+ *
+ * This allows the creation of file variant with different extension to the original file.
+ */
+trait AlternativeFileExtensionTrait
+{
+
+    /**
+     * Rewrite a filename with a different extension
+     * @param string $filename
+     * @param string $variant
+     * @return string
+     */
+    public function rewriteVariantExtension(string $filename, string $variant): string
+    {
+        return $this->swapExtension($filename, $variant, 1);
+    }
+
+    /**
+     * Rewrite a filename to use the original extension for the provided variant.
+     * @param string $filename
+     * @param string $variant
+     * @return string
+     */
+    public function restoreOriginalExtension(string $filename, string $variant): string
+    {
+        return $this->swapExtension($filename, $variant, 0);
+    }
+
+    /**
+     * Construct the original or alternative filname extension for the given filename and variant string.
+     * @param string $filename Original filename without variant
+     * @param string $variant Full variant list
+     * @param int $extIndex Wether we want the original extension (0) or the new extension (1)
+     * @return string
+     */
+    private function swapExtension(
+        string $filename,
+        string $variant,
+        int $extIndex
+    ): string {
+        // If there's no variant at all, we can rewrite the filenmane
+        if (empty($variant)) {
+            return $filename;
+        }
+
+        // Split variant string in variant list
+        $subVariants = explode('_', $variant);
+
+        // Split our filename into a filename and extension part
+        if (!preg_match('/(.+)\.([a-z\d]+)$/i', $filename, $matches)) {
+            return $filename;
+        }
+        [$_, $filenameWitoutExtension, $extension] = $matches;
+
+        // Loop our variant list until we find our special file extension swap variant
+        foreach ($subVariants as $subVariant) {
+            $extSwapVariant = FileIDHelper::EXTENSION_REWRITE_VARIANT;
+            if (preg_match("/^$extSwapVariant(.+)$/", $subVariant, $matches)) {
+                [$_, $base64] = $matches;
+
+                /**
+                 * This array always contain 2 values: The orignial extension and the new extension
+                 * @var array $extensionData
+                 */
+                $extensionData = Convert::base64url_decode($base64);
+                $extension = $extensionData[$extIndex];
+            }
+        }
+
+        return $filenameWitoutExtension . '.' . $extension;
+    }
+}

src/FilenameParsing/FileIDHelper.php

@@ -7,6 +7,10 @@
  */
 interface FileIDHelper
 {
+    /**
+     * A special variant type that can be used to encode a variant filename with a different extension.
+     */
+    public const EXTENSION_REWRITE_VARIANT = 'extRewrite';
 
     /**
      * Map file tuple (hash, name, variant) to a filename to be used by flysystem

src/FilenameParsing/HashFileIDHelper.php

@@ -17,6 +17,7 @@
 class HashFileIDHelper implements FileIDHelper
 {
     use Injectable;
+    use AlternativeFileExtensionTrait;
 
     /**
      * Default length at which hashes are truncated.
@@ -39,6 +40,11 @@ public function buildFileID($filename, $hash = null, $variant = null, $cleanfile
         if ($cleanfilename) {
             $filename = $this->cleanFilename($filename);
         }
+
+        if ($variant) {
+            $filename = $this->rewriteVariantExtension($filename, $variant);
+        }
+
         $name = basename($filename ?? '');
 
         // Split extension
@@ -88,10 +94,16 @@ public function parseFileID($fileID)
         }
 
         $filename = $matches['folder'] . $matches['basename'] . $matches['extension'];
+        $variant = isset($matches['variant']) ? $matches['variant'] : '';
+
+        if (isset($variant)) {
+            $filename = $this->restoreOriginalExtension($filename, $variant);
+        }
+
         return new ParsedFileID(
             $filename,
             $matches['hash'],
-            isset($matches['variant']) ? $matches['variant'] : '',
+            $variant,
             $fileID
         );
     }

src/FilenameParsing/NaturalFileIDHelper.php

@@ -14,6 +14,7 @@
 class NaturalFileIDHelper implements FileIDHelper
 {
     use Injectable;
+    use AlternativeFileExtensionTrait;
 
     public function buildFileID($filename, $hash = null, $variant = null, $cleanfilename = true)
     {
@@ -27,6 +28,11 @@ public function buildFileID($filename, $hash = null, $variant = null, $cleanfile
         if ($cleanfilename) {
             $filename = $this->cleanFilename($filename);
         }
+
+        if ($variant) {
+            $filename = $this->rewriteVariantExtension($filename, $variant);
+        }
+
         $name = basename($filename ?? '');
 
         // Split extension
@@ -57,7 +63,6 @@ public function buildFileID($filename, $hash = null, $variant = null, $cleanfile
         return $fileID;
     }
 
-
     public function cleanFilename($filename)
     {
         // Swap backslash for forward slash
@@ -77,10 +82,16 @@ public function parseFileID($fileID)
         }
 
         $filename = $matches['folder'] . $matches['basename'] . $matches['extension'];
+        $variant = isset($matches['variant']) ? $matches['variant'] : '';
+
+        if (isset($variant)) {
+            $filename = $this->restoreOriginalExtension($filename, $variant);
+        }
+
         return new ParsedFileID(
             $filename,
             '',
-            isset($matches['variant']) ? $matches['variant'] : '',
+            $variant,
             $fileID
         );
     }

src/ImageBackendFactory.php

@@ -37,9 +37,15 @@ public function __construct(Factory $creator)
      */
     public function create($service, array $params = [])
     {
-        /** @var AssetContainer $assetContainer */
+        /** @var AssetContainer|null $assetContainer */
         $assetContainer = reset($params);
-        if (!$assetContainer instanceof AssetContainer) {
+
+        // If no asset container was passed in, create a new uncached image backend
+        if (!$assetContainer) {
+            return $this->creator->create($service, $params);
+        }
+
+        if (!($assetContainer instanceof AssetContainer)) {
             throw new BadMethodCallException("Can only create Image_Backend for " . AssetContainer::class);
         }
 

src/ImageManipulation.php

@@ -4,6 +4,7 @@
 
 use InvalidArgumentException;
 use LogicException;
+use SilverStripe\Assets\FilenameParsing\FileIDHelper;
 use SilverStripe\Assets\Storage\AssetContainer;
 use SilverStripe\Assets\Storage\AssetStore;
 use SilverStripe\Assets\Storage\DBFile;
@@ -840,6 +841,18 @@ public function isHeight($height)
         return $this->getHeight() === $height;
     }
 
+    /**
+     * @param string $newExtension
+     * @param callable $callback
+     * @return DBFile The manipulated file
+     */
+    public function manipulateExtension(string $newExtension, callable $callback)
+    {
+        $pathParts = pathinfo($this->getFilename());
+        $variant = $this->variantName(FileIDHelper::EXTENSION_REWRITE_VARIANT, $pathParts['extension'], $newExtension);
+        return $this->manipulate($variant, $callback);
+    }
+
     /**
      * Wrapper for manipulate that passes in and stores Image_Backend objects instead of tuples
      *

src/InterventionBackend.php

@@ -366,8 +366,10 @@ public function writeToStore(AssetStore $assetStore, $filename, $hash = null, $v
                 throw new BadMethodCallException("Cannot write corrupt file to store");
             }
 
+            // Make sure we're using the extension of the variant file, which can differ from the original file
+            $url = $assetStore->getAsURL($filename, $hash, $variant, false);
+            $extension = pathinfo($url, PATHINFO_EXTENSION);
             // Save file
-            $extension = pathinfo($filename ?? '', PATHINFO_EXTENSION);
             $result = $assetStore->setFromString(
                 $resource->encode($extension, $this->getQuality())->getEncoded(),
                 $filename,