userfunc condition for detecting mobile device

Since TYPO3 7 the condition 'device' and 'useragent' are deprecated. No I'm looking for a userFunc to use as a condition for detecting mobile devices. My aim is to hide or to show some special pages on mobile devices. I used the extension 'contexts_wurfl' for a while but I guess that there should be 'smaller solutions'.

Thanks for any help.

You can accomplish this with TypoScript using the PAGE Object.

The code below shows you how to execute your own code before executing something else (like the template engine/content rendering etcetera).

page.01 = USER_INT
page.01 {
    userFunc = TYPO3\MyExt\Utility\MobileDeviceUtility->detectMobileDevice
}

And in code:

<?php
namespace TYPO3\MyExt\Utility;

class MobileDeviceUtility {

    /**
     * Is Mobile Device
     *
     * @return boolean
     */
    static public function isMobileDevice() {

        // calculates if the user agent is on a mobile device

        return TRUE;
    }

    /**
     * Detect Mobile Device
     *
     * @param string $content
     * @param array $conf
     * @return void
     */ 
    static public function detectMobileDevice($content, array $conf = NULL) {

        global $TSFE;

        if (self::isMobileDevice()
              && (boolean) $TSFE->page['mycustom_device_checkbox']
        ) {
            // do something 
        }

    }

}

OR otherwise you should create your own condition [YourVendor\YourPackage\YourCondition = var1 = value1, var2 != value2, ...].