Simplified the usage by providing methods to easily prepare and send the post request

example/sender.php

@@ -14,31 +14,7 @@
         ->addData('fed[]', 'def')
         ->addFile('file[]', __DIR__ . '/receiver.php')
         ->addFile('file[]', __DIR__ . '/sender.php')
-        ->build();
+        ->send("http://localhost/receiver.php");
 } catch (FormDataBuilderException $e) {
     die($e->getMessage());
 }
-
-$host = "localhost";
-$path = "/receiver.php";
-$fp = fsockopen($host, 8888);
-if ($fp) {
-    $str = "POST " . $path . " HTTP/1.1\r\n";
-    $str .= "Host: " . $host . "\r\n";
-    $str .= "Content-Type: " . $formDataBuilder->getContentType() . "\r\n";
-    $str .= "Content-Length: " . strlen($data) . "\r\n";
-    $str .= "Connection: close\r\n\r\n";
-
-    $str .= $data;
-
-    fwrite($fp, $str);
-
-    $result = '';
-    while (!feof($fp)) {
-        $result .= fgets($fp, 128);
-    }
-    fclose($fp);
-
-    $response = explode("\r\n\r\n", $result);
-    echo $response[1];
-}

src/MultipartFormDataBuilder/FormDataBuilder.php

@@ -7,6 +7,7 @@ class FormDataBuilder
 
     private array $data = [];
     private array $files = [];
+    private array $headers = [];
     private string $boundary;
 
     public function __construct()
@@ -33,6 +34,20 @@ public function addFile(string $name, string $path): self
         return $this;
     }
 
+    /**
+     * @param string $header one valid http header as a single line string
+     * 
+     * @throws FormDataBuilderException
+     */
+    public function addHeader(string $header)
+    {
+        if(!$header){
+            throw new FormDataBuilderException('No header provided');
+        }
+
+        $this->headers[] = $header;
+    }
+
     /**
      * @return string
      */
@@ -46,6 +61,63 @@ public function getContentType(): string
         return 'multipart/form-data; boundary=' . $this->boundary;
     }
 
+
+    /**
+     * @param string $url Url to send the request to
+     * 
+     * @return string
+     * 
+     * @throws FormDataBuilderException
+     */
+    public function send(string $url): string
+    {
+        $host = parse_url($url,PHP_URL_HOST);
+        $path = parse_url($url,PHP_URL_PATH);
+        $port = parse_url($url,PHP_URL_PORT);
+
+        if($port != ""){
+            $host .= ":" . $port;
+        }
+
+        if(!$host || !$path){
+            throw new FormDataBuilderException('Invalid url: '.$url);
+        }
+
+        $data = $this->build();
+
+        $fp = fsockopen($host, 8888);
+        if ($fp) {
+
+            $str = "POST " . $path . " HTTP/1.1\r\n";
+            $str .= "Host: " . $host . "\r\n";
+            foreach ($this->headers as $header) {
+                $str .= $header . "\r\n";
+            }
+            $str .= "Content-Type: " . $this->getContentType() . "\r\n";
+            $str .= "Content-Length: " . strlen($data) . "\r\n";
+            $str .= "Connection: close\r\n\r\n";
+
+            $str .= $data;
+
+            $success = fwrite($fp, $str);
+            if(!$success){
+                throw new FormDataBuilderException('Fail to send the request');
+            }
+
+            $result = '';
+            while (!feof($fp)) {
+                $result .= fgets($fp, 128);
+            }
+            fclose($fp);
+
+            $response = explode("\r\n\r\n", $result);
+            return $response[1];
+        }
+        else{
+            throw new FormDataBuilderException('Unable to open socket to host: '.$host);
+        }
+    }
+
     public function build(): string
     {
         $eol = "\r\n";
@@ -67,6 +139,10 @@ public function build(): string
             $value = file_get_contents($filePath);
             $fileContentType = finfo_file($finfo, $filePath);
 
+            if(!$fileContentType){
+                throw new FormDataBuilderException('Unable to identify the content type of one of the files: '.$filePath);
+            }
+
             $data .= '--' . $this->boundary . $eol . 'Content-Disposition: form-data; name="' . $key . '"; '
                 . 'filename="'.basename($filePath).'"' . $eol
                 . 'Content-Type: ' . $fileContentType . $eol