[PHP-Client] Allow Content-Type merge-match+json for encoding (#19479)

* Allow Content-Type merge-match+json for encoding

* Changes JSON recognition to more flexible regex

* Removes now useless JSON format list

* Removes empty spaces

* Adds explanatory PHPDoc comment

* Moves Json-detection to class HeaderSelector

.ddev/web-build/Dockerfile.maven

@@ -0,0 +1 @@
+RUN apt update && apt install -y maven

modules/openapi-generator/src/main/resources/php/HeaderSelector.mustache

@@ -76,7 +76,7 @@ class HeaderSelector
         }
 
         # If none of the available Accept headers is of type "json", then just use all them
-        $headersWithJson = preg_grep('~(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$~', $accept);
+        $headersWithJson = $this->selectJsonMimeList($accept);
         if (count($headersWithJson) === 0) {
             return implode(',', $accept);
         }
@@ -86,6 +86,34 @@ class HeaderSelector
         return $this->getAcceptHeaderWithAdjustedWeight($accept, $headersWithJson);
     }
 
+    /**
+    * Detects whether a string contains a valid JSON mime type
+    *
+    * @param string $searchString
+    * @return bool
+    */
+    public function isJsonMime(string $searchString): bool
+    {
+        return preg_match('~^application/(json|[\w!#$&.+-^_]+\+json)\s*(;|$)~', $searchString) === 1;
+    }
+    
+    /**
+    * Select all items from a list containing a JSON mime type
+    *
+    * @param array $mimeList
+    * @return array
+    */
+    private function selectJsonMimeList(array $mimeList): array {
+        $jsonMimeList = [];
+        foreach ($mimeList as $mime) {
+            if($this->isJsonMime($mime)) {
+                $jsonMimeList[] = $mime;
+            }
+        }
+        return $jsonMimeList;
+    }
+
+
     /**
     * Create an Accept header string from the given "Accept" headers array, recalculating all weights
     *

modules/openapi-generator/src/main/resources/php/libraries/psr-18/api.mustache

@@ -613,7 +613,7 @@ use function sprintf;
         // for model (json/xml)
         {{#bodyParams}}
         if (isset(${{paramName}})) {
-            if ($headers['Content-Type'] === 'application/json') {
+            if ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode(ObjectSerializer::sanitizeForSerialization(${{paramName}}));
             } else {
                 $httpBody = ${{paramName}};
@@ -637,7 +637,7 @@ use function sprintf;
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {

samples/client/petstore/php/OpenAPIClient-php/lib/HeaderSelector.php

@@ -85,7 +85,7 @@ class HeaderSelector
         }
 
         # If none of the available Accept headers is of type "json", then just use all them
-        $headersWithJson = preg_grep('~(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$~', $accept);
+        $headersWithJson = $this->selectJsonMimeList($accept);
         if (count($headersWithJson) === 0) {
             return implode(',', $accept);
         }
@@ -95,6 +95,34 @@ class HeaderSelector
         return $this->getAcceptHeaderWithAdjustedWeight($accept, $headersWithJson);
     }
 
+    /**
+    * Detects whether a string contains a valid JSON mime type
+    *
+    * @param string $searchString
+    * @return bool
+    */
+    public function isJsonMime(string $searchString): bool
+    {
+        return preg_match('~^application/(json|[\w!#$&.+-^_]+\+json)\s*(;|$)~', $searchString) === 1;
+    }
+    
+    /**
+    * Select all items from a list containing a JSON mime type
+    *
+    * @param array $mimeList
+    * @return array
+    */
+    private function selectJsonMimeList(array $mimeList): array {
+        $jsonMimeList = [];
+        foreach ($mimeList as $mime) {
+            if($this->isJsonMime($mime)) {
+                $jsonMimeList[] = $mime;
+            }
+        }
+        return $jsonMimeList;
+    }
+
+
     /**
     * Create an Accept header string from the given "Accept" headers array, recalculating all weights
     *

samples/client/petstore/php/psr-18/lib/Api/AnotherFakeApi.php

@@ -376,7 +376,7 @@ class AnotherFakeApi
 
         // for model (json/xml)
         if (isset($client)) {
-            if ($headers['Content-Type'] === 'application/json') {
+            if ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode(ObjectSerializer::sanitizeForSerialization($client));
             } else {
                 $httpBody = $client;
@@ -396,7 +396,7 @@ class AnotherFakeApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {

samples/client/petstore/php/psr-18/lib/Api/DefaultApi.php

@@ -371,7 +371,7 @@ class DefaultApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {

samples/client/petstore/php/psr-18/lib/Api/FakeApi.php

@@ -371,7 +371,7 @@ class FakeApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -907,7 +907,7 @@ class FakeApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -1119,7 +1119,7 @@ class FakeApi
 
         // for model (json/xml)
         if (isset($pet)) {
-            if ($headers['Content-Type'] === 'application/json') {
+            if ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode(ObjectSerializer::sanitizeForSerialization($pet));
             } else {
                 $httpBody = $pet;
@@ -1139,7 +1139,7 @@ class FakeApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -1357,7 +1357,7 @@ class FakeApi
 
         // for model (json/xml)
         if (isset($body)) {
-            if ($headers['Content-Type'] === 'application/json') {
+            if ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode(ObjectSerializer::sanitizeForSerialization($body));
             } else {
                 $httpBody = $body;
@@ -1377,7 +1377,7 @@ class FakeApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -1595,7 +1595,7 @@ class FakeApi
 
         // for model (json/xml)
         if (isset($outer_composite)) {
-            if ($headers['Content-Type'] === 'application/json') {
+            if ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode(ObjectSerializer::sanitizeForSerialization($outer_composite));
             } else {
                 $httpBody = $outer_composite;
@@ -1615,7 +1615,7 @@ class FakeApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -1833,7 +1833,7 @@ class FakeApi
 
         // for model (json/xml)
         if (isset($body)) {
-            if ($headers['Content-Type'] === 'application/json') {
+            if ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode(ObjectSerializer::sanitizeForSerialization($body));
             } else {
                 $httpBody = $body;
@@ -1853,7 +1853,7 @@ class FakeApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -2071,7 +2071,7 @@ class FakeApi
 
         // for model (json/xml)
         if (isset($body)) {
-            if ($headers['Content-Type'] === 'application/json') {
+            if ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode(ObjectSerializer::sanitizeForSerialization($body));
             } else {
                 $httpBody = $body;
@@ -2091,7 +2091,7 @@ class FakeApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -2315,7 +2315,7 @@ class FakeApi
 
         // for model (json/xml)
         if (isset($outer_object_with_enum_property)) {
-            if ($headers['Content-Type'] === 'application/json') {
+            if ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode(ObjectSerializer::sanitizeForSerialization($outer_object_with_enum_property));
             } else {
                 $httpBody = $outer_object_with_enum_property;
@@ -2335,7 +2335,7 @@ class FakeApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -2614,7 +2614,7 @@ class FakeApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -2801,7 +2801,7 @@ class FakeApi
 
         // for model (json/xml)
         if (isset($request_body)) {
-            if ($headers['Content-Type'] === 'application/json') {
+            if ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode(ObjectSerializer::sanitizeForSerialization($request_body));
             } else {
                 $httpBody = $request_body;
@@ -2821,7 +2821,7 @@ class FakeApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -3000,7 +3000,7 @@ class FakeApi
 
         // for model (json/xml)
         if (isset($body)) {
-            if ($headers['Content-Type'] === 'application/json') {
+            if ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode(ObjectSerializer::sanitizeForSerialization($body));
             } else {
                 $httpBody = $body;
@@ -3020,7 +3020,7 @@ class FakeApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -3199,7 +3199,7 @@ class FakeApi
 
         // for model (json/xml)
         if (isset($file_schema_test_class)) {
-            if ($headers['Content-Type'] === 'application/json') {
+            if ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode(ObjectSerializer::sanitizeForSerialization($file_schema_test_class));
             } else {
                 $httpBody = $file_schema_test_class;
@@ -3219,7 +3219,7 @@ class FakeApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -3420,7 +3420,7 @@ class FakeApi
 
         // for model (json/xml)
         if (isset($user)) {
-            if ($headers['Content-Type'] === 'application/json') {
+            if ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode(ObjectSerializer::sanitizeForSerialization($user));
             } else {
                 $httpBody = $user;
@@ -3440,7 +3440,7 @@ class FakeApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -3672,7 +3672,7 @@ class FakeApi
 
         // for model (json/xml)
         if (isset($client)) {
-            if ($headers['Content-Type'] === 'application/json') {
+            if ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode(ObjectSerializer::sanitizeForSerialization($client));
             } else {
                 $httpBody = $client;
@@ -3692,7 +3692,7 @@ class FakeApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -4087,7 +4087,7 @@ class FakeApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -4400,7 +4400,7 @@ class FakeApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -4708,7 +4708,7 @@ class FakeApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -4899,7 +4899,7 @@ class FakeApi
 
         // for model (json/xml)
         if (isset($request_body)) {
-            if ($headers['Content-Type'] === 'application/json') {
+            if ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode(ObjectSerializer::sanitizeForSerialization($request_body));
             } else {
                 $httpBody = $request_body;
@@ -4919,7 +4919,7 @@ class FakeApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -5106,7 +5106,7 @@ class FakeApi
 
         // for model (json/xml)
         if (isset($test_inline_freeform_additional_properties_request)) {
-            if ($headers['Content-Type'] === 'application/json') {
+            if ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode(ObjectSerializer::sanitizeForSerialization($test_inline_freeform_additional_properties_request));
             } else {
                 $httpBody = $test_inline_freeform_additional_properties_request;
@@ -5126,7 +5126,7 @@ class FakeApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -5346,7 +5346,7 @@ class FakeApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -5660,7 +5660,7 @@ class FakeApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -5847,7 +5847,7 @@ class FakeApi
 
         // for model (json/xml)
         if (isset($request_body)) {
-            if ($headers['Content-Type'] === 'application/json') {
+            if ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode(ObjectSerializer::sanitizeForSerialization($request_body));
             } else {
                 $httpBody = $request_body;
@@ -5867,7 +5867,7 @@ class FakeApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {

samples/client/petstore/php/psr-18/lib/Api/FakeClassnameTags123Api.php

@@ -376,7 +376,7 @@ class FakeClassnameTags123Api
 
         // for model (json/xml)
         if (isset($client)) {
-            if ($headers['Content-Type'] === 'application/json') {
+            if ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode(ObjectSerializer::sanitizeForSerialization($client));
             } else {
                 $httpBody = $client;
@@ -396,7 +396,7 @@ class FakeClassnameTags123Api
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {

samples/client/petstore/php/psr-18/lib/Api/PetApi.php

@@ -356,7 +356,7 @@ class PetApi
 
         // for model (json/xml)
         if (isset($pet)) {
-            if ($headers['Content-Type'] === 'application/json') {
+            if ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode(ObjectSerializer::sanitizeForSerialization($pet));
             } else {
                 $httpBody = $pet;
@@ -376,7 +376,7 @@ class PetApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -602,7 +602,7 @@ class PetApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -859,7 +859,7 @@ class PetApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -1117,7 +1117,7 @@ class PetApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -1375,7 +1375,7 @@ class PetApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -1592,7 +1592,7 @@ class PetApi
 
         // for model (json/xml)
         if (isset($pet)) {
-            if ($headers['Content-Type'] === 'application/json') {
+            if ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode(ObjectSerializer::sanitizeForSerialization($pet));
             } else {
                 $httpBody = $pet;
@@ -1612,7 +1612,7 @@ class PetApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -1847,7 +1847,7 @@ class PetApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -2131,7 +2131,7 @@ class PetApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -2421,7 +2421,7 @@ class PetApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {

samples/client/petstore/php/psr-18/lib/Api/StoreApi.php

@@ -353,7 +353,7 @@ class StoreApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -588,7 +588,7 @@ class StoreApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -854,7 +854,7 @@ class StoreApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -1086,7 +1086,7 @@ class StoreApi
 
         // for model (json/xml)
         if (isset($order)) {
-            if ($headers['Content-Type'] === 'application/json') {
+            if ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode(ObjectSerializer::sanitizeForSerialization($order));
             } else {
                 $httpBody = $order;
@@ -1106,7 +1106,7 @@ class StoreApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {

samples/client/petstore/php/psr-18/lib/Api/UserApi.php

@@ -331,7 +331,7 @@ class UserApi
 
         // for model (json/xml)
         if (isset($user)) {
-            if ($headers['Content-Type'] === 'application/json') {
+            if ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode(ObjectSerializer::sanitizeForSerialization($user));
             } else {
                 $httpBody = $user;
@@ -351,7 +351,7 @@ class UserApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -538,7 +538,7 @@ class UserApi
 
         // for model (json/xml)
         if (isset($user)) {
-            if ($headers['Content-Type'] === 'application/json') {
+            if ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode(ObjectSerializer::sanitizeForSerialization($user));
             } else {
                 $httpBody = $user;
@@ -558,7 +558,7 @@ class UserApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -745,7 +745,7 @@ class UserApi
 
         // for model (json/xml)
         if (isset($user)) {
-            if ($headers['Content-Type'] === 'application/json') {
+            if ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode(ObjectSerializer::sanitizeForSerialization($user));
             } else {
                 $httpBody = $user;
@@ -765,7 +765,7 @@ class UserApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -974,7 +974,7 @@ class UserApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -1228,7 +1228,7 @@ class UserApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -1507,7 +1507,7 @@ class UserApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -1697,7 +1697,7 @@ class UserApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {
@@ -1903,7 +1903,7 @@ class UserApi
 
         // for model (json/xml)
         if (isset($user)) {
-            if ($headers['Content-Type'] === 'application/json') {
+            if ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode(ObjectSerializer::sanitizeForSerialization($user));
             } else {
                 $httpBody = $user;
@@ -1923,7 +1923,7 @@ class UserApi
                 // for HTTP post (form)
                 $httpBody = new MultipartStream($multipartContents);
 
-            } elseif ($headers['Content-Type'] === 'application/json') {
+            } elseif ($this->headerSelector->isJsonMime($headers['Content-Type'])) {
                 $httpBody = json_encode($formParams);
 
             } else {

samples/client/petstore/php/psr-18/lib/HeaderSelector.php

@@ -85,7 +85,7 @@ class HeaderSelector
         }
 
         # If none of the available Accept headers is of type "json", then just use all them
-        $headersWithJson = preg_grep('~(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$~', $accept);
+        $headersWithJson = $this->selectJsonMimeList($accept);
         if (count($headersWithJson) === 0) {
             return implode(',', $accept);
         }
@@ -95,6 +95,34 @@ class HeaderSelector
         return $this->getAcceptHeaderWithAdjustedWeight($accept, $headersWithJson);
     }
 
+    /**
+    * Detects whether a string contains a valid JSON mime type
+    *
+    * @param string $searchString
+    * @return bool
+    */
+    public function isJsonMime(string $searchString): bool
+    {
+        return preg_match('~^application/(json|[\w!#$&.+-^_]+\+json)\s*(;|$)~', $searchString) === 1;
+    }
+    
+    /**
+    * Select all items from a list containing a JSON mime type
+    *
+    * @param array $mimeList
+    * @return array
+    */
+    private function selectJsonMimeList(array $mimeList): array {
+        $jsonMimeList = [];
+        foreach ($mimeList as $mime) {
+            if($this->isJsonMime($mime)) {
+                $jsonMimeList[] = $mime;
+            }
+        }
+        return $jsonMimeList;
+    }
+
+
     /**
     * Create an Accept header string from the given "Accept" headers array, recalculating all weights
     *