Add take element screenshot command

Author: sapzape

lib/Remote/DriverCommand.php

@@ -149,6 +149,7 @@ class DriverCommand
     // W3C specific
     const ACTIONS = 'actions';
     const GET_ELEMENT_PROPERTY = 'getElementProperty';
+    const TAKE_ELEMENT_SCREENSHOT = 'takeElementScreenshot';
 
     private function __construct()
     {

lib/Remote/HttpCommandExecutor.php

@@ -129,6 +129,10 @@ class HttpCommandExecutor implements WebDriverCommandExecutor
         DriverCommand::STATUS => ['method' => 'GET', 'url' => '/status'],
         DriverCommand::SUBMIT_ELEMENT => ['method' => 'POST', 'url' => '/session/:sessionId/element/:id/submit'],
         DriverCommand::SCREENSHOT => ['method' => 'GET', 'url' => '/session/:sessionId/screenshot'],
+        DriverCommand::TAKE_ELEMENT_SCREENSHOT => [
+            'method' => 'GET',
+            'url' => '/session/:sessionId/element/:id/screenshot',
+        ],
         DriverCommand::TOUCH_SINGLE_TAP => ['method' => 'POST', 'url' => '/session/:sessionId/touch/click'],
         DriverCommand::TOUCH_DOWN => ['method' => 'POST', 'url' => '/session/:sessionId/touch/down'],
         DriverCommand::TOUCH_DOUBLE_TAP => ['method' => 'POST', 'url' => '/session/:sessionId/touch/doubleclick'],

lib/Remote/RemoteWebElement.php

@@ -431,6 +431,27 @@ public function getID()
         return $this->id;
     }
 
+    /**
+     * Take screenshot of a specific element.
+     *
+     * @param string $save_as The path of the screenshot to be saved.
+     * @return string The screenshot in PNG format.
+     */
+    public function takeElementScreenshot($save_as = null)
+    {
+        $screenshot = base64_decode(
+            $this->executor->execute(
+                DriverCommand::TAKE_ELEMENT_SCREENSHOT,
+                [':id' => $this->id]
+            )
+        );
+        if ($save_as) {
+            file_put_contents($save_as, $screenshot);
+        }
+
+        return $screenshot;
+    }
+
     /**
      * Test if two element IDs refer to the same DOM element.
      *

lib/WebDriverElement.php

@@ -132,4 +132,13 @@ public function submit();
      * @return string The opaque ID.
      */
     public function getID();
+
+    /**
+     * Take screenshot of a specific element.
+     *
+     * @param string $save_as The path of the screenshot to be saved.
+     * @return string The screenshot in PNG format.
+     * @todo Add in next major release (BC)
+     */
+    //public function takeElementScreenshot($save_as = null);
 }