Need advice on `No valid user-agent has been set` PHP Fatal error

[trendoman]

Need advice on `No valid user-agent has been set` PHP Fatal error

[maverik23]

same here

[trendoman]

I am reading a few postings on Stack that basically revolve around fact that absent user-agent (not empty string, but completely missing one) is a valid request.
https://stackoverflow.com/questions/24274789/is-lack-of-user-agent-in-http-request-valid

A posting reported that visitors with a missing UA successfulle performed purchases on website (possibly this is a disinformation lol)
https://stackoverflow.com/questions/71527200/how-am-i-getting-users-with-no-user-agent-string

So, meanwhile I am going to try setting it explicitly to an empty string e.g.

if( false === $MB->hasUserAgent() ){ $MB->setUserAgent(''); }

[serbanghita]

As of https://github.com/serbanghita/Mobile-Detect/releases/tag/4.8.04 the rule is that if there is no User-Agent provided (even after we tried to auto-initialize from known $_SERVER['...'] variables, this will throw an exception, because it's actually an exceptional situation and you don't want to go on with the processing.

The recommendation is the following:

$detect = new MobileDetect();

$isMobile = false;
try {
    $isMobile = $detect->isMobile();
} catch (\Detection\Exception\MobileDetectException $e) {
  // do nothing, or log this to your error logs.
}

var_dump($isMobile);

[serbanghita]

Added this example to https://github.com/serbanghita/Mobile-Detect/blob/4.8.x/scripts/example.php