ClientHints plan upgrade

[sanchezzzhak]

https://www.chromium.org/updates/ua-reduction/#proposed-rollout-plan

according to this information, the user-agent will be depersonalized at maximum for browsers: Chromium, Opera, YandexBrowser, Brave etc

we will need to adjust all regular expressions and abandon the pattern
BrandName ([^;)]+)(?: Build|[;)]) or set like this BrandName ([^;)]+)(?: Build|[;)]|$)

more details https://51degrees.com/blog/countdown-to-gday-phase-5-reduced-desktop-ua

[zhouhui]

Hi @sanchezzzhak, I have a question about reduced user-agent: Is it possible to detect device-type( mobile, tablet, desktop, etc.) in reduced user agent only without client-hints? Thanks!

[sanchezzzhak]

Hi, yes it will still be possible

[zhouhui]

Hi, yes it will still be possible

Thanks for your quick reply. From the file 'mobiles.yml', I see some devices types are detected in model regex, for an example:

Microsoft:
  regex: 'KIN\.(One|Two)|RM-(?:1010|1031|106[57]|107[23467]|1089|109[02]|1096|1099|1109|111[348]|1127|1141|115[24]|994)|Microsoft; Lumia|Lumia (?:1530|1320|950|850|650|640|550|535|435)|Corporation/Surface|Surface Duo|Surface 3'
  device: 'smartphone'
  models:
    - regex: 'Surface Duo 2'
      device: 'tablet'
      model: 'Surface Duo 2'

And from the google ua-reduction doc, the part of Model would be reduced in user agent, so I guess, for the target devices of 'Surface Duo 2', the device-type would be detected as 'smartphone' instead of the accurate result 'tablet' with only reduced ua (without client-hints). Am I correct? If so, do we have other ways to get the accurate device-type? Thanks a lot.

[sanchezzzhak]

the type of device, when the brand and model of the device are unknown, is determined by several factors

device-detector/DeviceDetector.php

Lines 926 to 934 in 3f55f64

	if (null === $this->device && 'Android' === $osFamily
	&& $this->matchUserAgent('Chrome/[\.0-9]*')
	) {
	if ($this->matchUserAgent('(?:Mobile|eliboM) Safari/')) {
	$this->device = AbstractDeviceParser::DEVICE_TYPE_SMARTPHONE;
	} elseif ($this->matchUserAgent('(?!Mobile )Safari/')) {
	$this->device = AbstractDeviceParser::DEVICE_TYPE_TABLET;
	}
	}

and further down the list.

If we know the device model, we are guaranteed to return the device type.
When we don't know the model of the device, it's all speculation.

Some tablet devices may return mobile types in the useragent string, this will be inaccurate here, but there are very few such devices. (this is due to the fact that the tablet has a SIM module, and the processor is used from a mobile device, processors for phones and tablets are most often different)