Add JS to your footer from within Extbase

SlideshowController.php

$pageRenderer = $GLOBALS['TSFE']->getPageRenderer();
$pageRenderer->addJsFooterLibrary(
    'jquerycycle',
    t3lib_div::getFileAbsFileName('EXT:simply_slideshow/Resources/Public/JavaScript/jquery.cycle.all.js')
);

Link: http://api.typo3.org/typo3v4/45/html/classt3lib___page_renderer.html#a566327d68ce46165b06f96afdd61922a

/**
 * 
 */
public function initializeAction() {
    $pageRenderer = $GLOBALS['TSFE']->getPageRenderer();
    $pageRenderer->addJsFooterLibrary(
        $this->extensionName,
        t3lib_div::getFileAbsFileName('EXT:simply_feuser_subscribe/Resources/Public/JavaScript/SimplyFeUserSubscribe.js')
    );
    parent::initializeAction();
}

TYPO3 7.6:

/**
 * 
 */
public function initializeAction() {
    $uniqueBlockNamePrefix = $this->request->getControllerVendorName() .'_'. $this->request->getControllerExtensionKey() . '_';
    $pageRenderer = \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance(\TYPO3\CMS\Core\Page\PageRenderer::class);
    $pageRenderer->addJsFooterLibrary(
        $uniqueBlockNamePrefix.'myJsBlockName1',
        \TYPO3\CMS\Core\Utility\ExtensionManagementUtility::siteRelPath($this->request->getControllerExtensionKey()) . 'Resources/Public/js/test.js'
    );
    parent::initializeAction();
}