PhpStorm - creating project for Extbase - typo3

Question

I am developing a TYPO3 Extbase extension with PhpStorm. I am getting hundreds of notifications saying that Field x could not be found e.g. Field 'request' not found in DownloadController.
The official documentation only covers NetBeans and eclipse.
How does it work in PhpStorm?

Answer 1

Add TYPO3 Sources
Open your Project Tree (ALT-1)
At the end you find "External Libraries" -> RightClick -> Configure PHP include Paths -> add your TYPO3 source path
Set the right php version there as well
PHP Docs Comments
Be sure to use the right php annotation headers for every function - PHPStorm resolves them for the parameter info, and ExtBase uses them as well.
Example from the TYPO3 Core:
/**
* Returns the absolute filename of a relative reference, resolves the "EXT:" prefix
* (way of referring to files inside extensions) and checks that the file is inside
* the PATH_site of the TYPO3 installation and implies a check with
* \TYPO3\CMS\Core\Utility\GeneralUtility::validPathStr().
*
* #param string $filename The input filename/filepath to evaluate
* #param bool $onlyRelative If $onlyRelative is set (which it is by default), then only return values relative to the current PATH_site is accepted.
* #param bool $relToTYPO3_mainDir If $relToTYPO3_mainDir is set, then relative paths are relative to PATH_typo3 constant - otherwise (default) they are relative to PATH_site
* #return string Returns the absolute filename of $filename if valid, otherwise blank string.
*/
public static function getFileAbsFileName($filename, $onlyRelative = true, $relToTYPO3_mainDir = false)
{
...
}