NEW: Implement accept attribute in FileField (closes #7279)

src/Forms/FileField.php

@@ -2,10 +2,11 @@
 
 namespace SilverStripe\Forms;
 
+use SilverStripe\Assets\File;
+use SilverStripe\Control\HTTP;
 use SilverStripe\Core\Injector\Injector;
 use SilverStripe\ORM\DataObject;
 use SilverStripe\ORM\DataObjectInterface;
-use SilverStripe\Assets\File;
 
 /**
  * Represents a file type which can be added to a form.
@@ -85,6 +86,43 @@ class FileField extends FormField implements FileHandleField
         return parent::Field($properties);
     }
 
+    public function getAttributes()
+    {
+        $attributes = parent::getAttributes();
+
+        $accept = $this->getAcceptFileTypes();
+        if ($accept) {
+            $attributes = array_merge(['accept' => implode(',', $accept)], $attributes);
+        }
+
+        return $attributes;
+    }
+
+    /**
+     * Returns a list of file extensions (and corresponding mime types) that will be accepted
+     *
+     * @return array
+     */
+    protected function getAcceptFileTypes()
+    {
+        $extensions = $this->getValidator()->getAllowedExtensions();
+        if (!$extensions) {
+            return [];
+        }
+
+        $accept = [];
+        $mimeTypes = HTTP::config()->uninherited('MimeTypes');
+        foreach ($extensions as $extension) {
+            $accept[] = ".{$extension}";
+            // Check for corresponding mime type
+            if (isset($mimeTypes[$extension])) {
+                $accept[] = $mimeTypes[$extension];
+            }
+        }
+
+        return array_unique($accept);
+    }
+
     /**
      * @param DataObject|DataObjectInterface $record
      */

tests/php/Forms/FileFieldTest.php

@@ -2,6 +2,7 @@
 
 namespace SilverStripe\Forms\Tests;
 
+use ReflectionMethod;
 use SilverStripe\Dev\FunctionalTest;
 use SilverStripe\Control\Controller;
 use SilverStripe\Forms\FileField;
@@ -11,7 +12,6 @@ use SilverStripe\Forms\RequiredFields;
 
 class FileFieldTest extends FunctionalTest
 {
-
     /**
      * Test a valid upload of a required file in a form. Error is set to 0, as the upload went well
      *
@@ -39,6 +39,24 @@ class FileFieldTest extends FunctionalTest
         $this->assertTrue($form->validationResult()->isValid());
     }
 
+    /**
+     * @skipUpgrade
+     */
+    public function testGetAcceptFileTypes()
+    {
+        $field = new FileField('image', 'Image');
+        $field->setAllowedExtensions('jpg', 'png');
+
+        $method = new ReflectionMethod($field, 'getAcceptFileTypes');
+        $method->setAccessible(true);
+        $allowed = $method->invoke($field);
+
+        $expected = ['.jpg', '.png', 'image/jpeg', 'image/png'];
+        foreach ($expected as $extensionOrMime) {
+            $this->assertContains($extensionOrMime, $allowed);
+        }
+    }
+
     /**
      * Test different scenarii for a failed upload : an error occured, no files where provided
      * @skipUpgrade