CODE EXAMPLE FOR PHP

silverstripe image upload field

  public function getCMSFields()
  {
        $fields = parent::getCMSFields();
        $fields->addFieldToTab('Root.Attachments',
             UploadField::create('Photo'));
        $fields->addFieldToTab('Root.Attachments',
            $brochure = UploadField::create(
                'Brochure',
                'Travel brochure,
                optional (PDF only)'
        ));
        $brochure->getValidator()
            ->setAllowedExtensions(['pdf']);
        return $fields;
  }