add tag header parser to cleanly respect custom glue

CHANGELOG.md

@@ -3,6 +3,12 @@ Changelog
 
 See also the [GitHub releases page](https://github.com/FriendsOfSymfony/FOSHttpCache/releases).
 
+2.15.0
+------
+
+* Provide a `TagHeaderParser` that can split up a tag header into the list of tags.
+  This allows to correctly handle non-default tag separators in all places.
+
 2.14.2
 ------
 

doc/symfony-cache-configuration.rst

@@ -208,8 +208,7 @@ you have the same configuration options as with the ``PurgeListener``. *Only
 set one of ``client_ips`` or ``client_matcher``*. Additionally, you can
 configure the HTTP method and header used for tag purging:
 
-* **client_ips**: String with IP or array of IPs that are allowed to
-  purge the cache.
+* **client_ips**: String with IP or array of IPs that are allowed to purge the cache.
 
   **default**: ``127.0.0.1``
 
@@ -230,6 +229,10 @@ configure the HTTP method and header used for tag purging:
 
   **default**: ``/``
 
+* **tags_parser**: Overwrite if you use a non-default glue to combine the tags in the header.
+  This option expects a `FOS\HttpCache\TagHeaderFormatter\TagHeaderParser` instance, configured
+  with the glue you want to use.
+
 To get cache tagging support, register the ``PurgeTagsListener`` and use the
 ``Psr6Store`` in your ``AppCache``::
 

src/ResponseTagger.php

@@ -14,6 +14,7 @@
 use FOS\HttpCache\Exception\InvalidTagException;
 use FOS\HttpCache\TagHeaderFormatter\CommaSeparatedTagHeaderFormatter;
 use FOS\HttpCache\TagHeaderFormatter\TagHeaderFormatter;
+use FOS\HttpCache\TagHeaderFormatter\TagHeaderParser;
 use Psr\Http\Message\ResponseInterface;
 use Symfony\Component\OptionsResolver\Options;
 use Symfony\Component\OptionsResolver\OptionsResolver;
@@ -96,6 +97,24 @@ public function getTagsHeaderValue()
         return $this->headerFormatter->getTagsHeaderValue($this->tags);
     }
 
+    /**
+     * Split the tag header into a list of tags.
+     *
+     * @param string|string[] $headers
+     *
+     * @return string[]
+     */
+    protected function parseTagsHeaderValue($headers): array
+    {
+        if ($this->headerFormatter instanceof TagHeaderParser) {
+            return $this->headerFormatter->parseTagsHeaderValue($headers);
+        }
+
+        return array_merge(...array_map(function ($header) {
+            return explode(',', $header);
+        }, $headers));
+    }
+
     /**
      * Check whether the tag handler has any tags to set on the response.
      *

src/SymfonyCache/PurgeTagsListener.php

@@ -11,6 +11,8 @@
 
 namespace FOS\HttpCache\SymfonyCache;
 
+use FOS\HttpCache\TagHeaderFormatter\CommaSeparatedTagHeaderFormatter;
+use FOS\HttpCache\TagHeaderFormatter\TagHeaderParser;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\OptionsResolver\OptionsResolver;
 use Toflar\Psr6HttpCacheStore\Psr6StoreInterface;
@@ -42,6 +44,11 @@ class PurgeTagsListener extends AccessControlledListener
      */
     private $tagsHeader;
 
+    /**
+     * @var TagHeaderParser
+     */
+    private $tagsParser;
+
     /**
      * When creating the purge listener, you can configure an additional option.
      *
@@ -65,6 +72,7 @@ public function __construct(array $options = [])
 
         $this->tagsMethod = $options['tags_method'];
         $this->tagsHeader = $options['tags_header'];
+        $this->tagsParser = $options['tags_parser'];
     }
 
     /**
@@ -125,11 +133,7 @@ public function handlePurgeTags(CacheEvent $event)
             $headers = $request->headers->get($this->tagsHeader, '', false);
         }
 
-        foreach ($headers as $header) {
-            foreach (explode(',', $header) as $tag) {
-                $tags[] = $tag;
-            }
-        }
+        $tags = $this->tagsParser->parseTagsHeaderValue($headers);
 
         if ($store->invalidateTags($tags)) {
             $response->setStatusCode(200, 'Purged');
@@ -151,9 +155,11 @@ protected function getOptionsResolver()
         $resolver->setDefaults([
             'tags_method' => static::DEFAULT_TAGS_METHOD,
             'tags_header' => static::DEFAULT_TAGS_HEADER,
+            'tags_parser' => new CommaSeparatedTagHeaderFormatter(),
         ]);
         $resolver->setAllowedTypes('tags_method', 'string');
         $resolver->setAllowedTypes('tags_header', 'string');
+        $resolver->setAllowedTypes('tags_parser', TagHeaderParser::class);
 
         return $resolver;
     }

src/TagHeaderFormatter/CommaSeparatedTagHeaderFormatter.php

@@ -16,7 +16,7 @@
  *
  * @author Yanick Witschi <yanick.witschi@terminal42.ch>
  */
-class CommaSeparatedTagHeaderFormatter implements TagHeaderFormatter
+class CommaSeparatedTagHeaderFormatter implements TagHeaderFormatter, TagHeaderParser
 {
     /**
      * @var string
@@ -53,4 +53,15 @@ public function getTagsHeaderValue(array $tags)
     {
         return implode($this->glue, $tags);
     }
+
+    public function parseTagsHeaderValue($tags): array
+    {
+        if (is_string($tags)) {
+            $tags = [$tags];
+        }
+
+        return array_merge(...array_map(function ($tagsFragment) {
+            return explode($this->glue, $tagsFragment);
+        }, $tags));
+    }
 }

src/TagHeaderFormatter/MaxHeaderValueLengthFormatter.php

@@ -21,7 +21,7 @@
  *
  * @author Yanick Witschi <yanick.witschi@terminal42.ch>
  */
-class MaxHeaderValueLengthFormatter implements TagHeaderFormatter
+class MaxHeaderValueLengthFormatter implements TagHeaderFormatter, TagHeaderParser
 {
     /**
      * @var TagHeaderFormatter
@@ -83,6 +83,15 @@ public function getTagsHeaderValue(array $tags)
         return $newValues;
     }
 
+    public function parseTagsHeaderValue($tags): array
+    {
+        if ($this->inner instanceof TagHeaderParser) {
+            return $this->inner->parseTagsHeaderValue($tags);
+        }
+
+        throw new \BadMethodCallException('The inner formatter does not implement '.TagHeaderParser::class);
+    }
+
     /**
      * @param string $value
      *

src/TagHeaderFormatter/TagHeaderParser.php

@@ -0,0 +1,29 @@
+<?php
+
+/*
+ * This file is part of the FOSHttpCache package.
+ *
+ * (c) FriendsOfSymfony <http://friendsofsymfony.github.com/>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace FOS\HttpCache\TagHeaderFormatter;
+
+/**
+ * The TagHeaderParser can convert the tag header into an array of tags.
+ *
+ * @author David Buchmann <mail@davidbu.ch>
+ */
+interface TagHeaderParser
+{
+    /**
+     * Split the tag header into a list of tags.
+     *
+     * @param string|string[] $tags
+     *
+     * @return string[]
+     */
+    public function parseTagsHeaderValue($tags): array;
+}

tests/Unit/TagHeaderFormatter/CommaSeparatedTagHeaderFormatterTest.php

@@ -46,4 +46,19 @@ public function testGetCustomGlueTagsHeaderValue()
         $this->assertSame('tag1', $formatter->getTagsHeaderValue(['tag1']));
         $this->assertSame('tag1 tag2 tag3', $formatter->getTagsHeaderValue(['tag1', 'tag2', 'tag3']));
     }
+
+    public function testParseTagsHeaderValue()
+    {
+        $parser = new CommaSeparatedTagHeaderFormatter();
+
+        $this->assertSame(['a', 'b', 'c'], $parser->parseTagsHeaderValue('a,b,c'));
+        $this->assertSame(['a', 'b', 'c'], $parser->parseTagsHeaderValue(['a', 'b,c']));
+    }
+
+    public function testParseCustomGlueTagsHeaderValue()
+    {
+        $parser = new CommaSeparatedTagHeaderFormatter(TagHeaderFormatter::DEFAULT_HEADER_NAME, ' ');
+
+        $this->assertSame(['a', 'b,c'], $parser->parseTagsHeaderValue('a b,c'));
+    }
 }