Fix php-curl-class#538: Allow objects implementing JsonSerializable to be serialized to JSON when passed as request data

Author: zachborboa

src/Curl/Curl.php

@@ -139,32 +139,39 @@ public function beforeSend($callback)
     public function buildPostData($data)
     {
         $binary_data = false;
-        if (is_array($data)) {
-            // Return JSON-encoded string when the request's content-type is JSON.
-            if (isset($this->headers['Content-Type']) &&
-                preg_match($this->jsonPattern, $this->headers['Content-Type'])) {
-                $data = \Curl\json_encode($data);
-            } else {
-                // Manually build a single-dimensional array from a multi-dimensional array as using curl_setopt($ch,
-                // CURLOPT_POSTFIELDS, $data) doesn't correctly handle multi-dimensional arrays when files are
-                // referenced.
-                if (ArrayUtil::is_array_multidim($data)) {
-                    $data = ArrayUtil::array_flatten_multidim($data);
-                }
 
-                // Modify array values to ensure any referenced files are properly handled depending on the support of
-                // the @filename API or CURLFile usage. This also fixes the warning "curl_setopt(): The usage of the
-                // @filename API for file uploading is deprecated. Please use the CURLFile class instead". Ignore
-                // non-file values prefixed with the @ character.
-                foreach ($data as $key => $value) {
-                    if (is_string($value) && strpos($value, '@') === 0 && is_file(substr($value, 1))) {
-                        $binary_data = true;
-                        if (class_exists('CURLFile')) {
-                            $data[$key] = new \CURLFile(substr($value, 1));
-                        }
-                    } elseif ($value instanceof \CURLFile) {
-                        $binary_data = true;
+        // Return JSON-encoded string when the request's content-type is JSON and the data is serializable.
+        if (isset($this->headers['Content-Type']) &&
+            preg_match($this->jsonPattern, $this->headers['Content-Type']) &&
+            (
+                is_array($data) ||
+                (
+                    is_object($data) &&
+                    interface_exists('JsonSerializable', false) &&
+                    $data instanceof \JsonSerializable
+                )
+            )) {
+            $data = \Curl\json_encode($data);
+        } elseif (is_array($data)) {
+            // Manually build a single-dimensional array from a multi-dimensional array as using curl_setopt($ch,
+            // CURLOPT_POSTFIELDS, $data) doesn't correctly handle multi-dimensional arrays when files are
+            // referenced.
+            if (ArrayUtil::is_array_multidim($data)) {
+                $data = ArrayUtil::array_flatten_multidim($data);
+            }
+
+            // Modify array values to ensure any referenced files are properly handled depending on the support of
+            // the @filename API or CURLFile usage. This also fixes the warning "curl_setopt(): The usage of the
+            // @filename API for file uploading is deprecated. Please use the CURLFile class instead". Ignore
+            // non-file values prefixed with the @ character.
+            foreach ($data as $key => $value) {
+                if (is_string($value) && strpos($value, '@') === 0 && is_file(substr($value, 1))) {
+                    $binary_data = true;
+                    if (class_exists('CURLFile')) {
+                        $data[$key] = new \CURLFile(substr($value, 1));
                     }
+                } elseif ($value instanceof \CURLFile) {
+                    $binary_data = true;
                 }
             }
         }

tests/PHPCurlClass/Helper.php

@@ -2,7 +2,7 @@
 
 namespace Helper;
 
-use Curl\Curl;
+use \Curl\Curl;
 
 class Test
 {

tests/PHPCurlClass/PHPCurlClassTest.php

@@ -5,6 +5,7 @@
 use \Curl\CaseInsensitiveArray;
 use \Curl\Curl;
 use \Helper\Test;
+use \Helper\User;
 
 class CurlTest extends \PHPUnit\Framework\TestCase
 {
@@ -3715,4 +3716,20 @@ public function testProxySettings()
         $curl->unsetProxy();
         $this->assertNull($curl->getOpt(CURLOPT_PROXY));
     }
+
+    public function testJsonSerializable()
+    {
+        if (!interface_exists('JsonSerializable')) {
+            $this->markTestSkipped();
+        }
+
+        $expected_response = '{"name":"Alice","email":"alice@example.com"}';
+
+        $user = new \Helper\User('Alice', 'alice@example.com');
+        $this->assertEquals($expected_response, json_encode($user));
+
+        $test = new Test();
+        $test->curl->setHeader('Content-Type', 'application/json');
+        $this->assertEquals($expected_response, $test->server('post_json', 'POST', $user));
+    }
 }

tests/PHPCurlClass/User.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace Helper;
+
+// Check interface exists to fix "Fatal error: Interface 'JsonSerializable' not found in ../tests/PHPCurlClass/User.php
+// on line X".
+if (interface_exists('JsonSerializable')) {
+    class User implements \JsonSerializable
+    {
+        private $name;
+        private $email;
+
+        public function __construct($name = null, $email = null)
+        {
+            $this->name = $name;
+            $this->email = $email;
+        }
+
+        public function jsonSerialize()
+        {
+            return array(
+                'name' => $this->name,
+                'email' => $this->email,
+            );
+        }
+    }
+}