[wp-trac] [WordPress Trac] #33704: Deprecate wp_is_mobile()

[WordPress Trac]

#33704: Deprecate wp_is_mobile()
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 Reporter:  johnbillion               |       Owner:
     Type:  enhancement               |      Status:  new
 Priority:  normal                    |   Milestone:  Awaiting Review
Component:  General                   |     Version:  3.4
 Severity:  normal                    |  Resolution:
 Keywords:  needs-patch dev-feedback  |     Focuses:  ui
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Comment (by akibjorklund):

 I went through all the instances of calls to `wp_is_mobile`. It is called
 34 times in 23 different files. I've roughly categorized the instances.

 '''1. To determine if a JavaScript that automatically sets focus to a
 field should be written: 5 instances

 Not sure if this is a good idea in general, but could be based on the
 viewport width just as well. At least makes sense to disable the feature
 on smaller screens as the virtual keyboard will take up valuable space.

 '''2. To print out a `mobile` or `ios` CSS class: 5 instances

 In `/wp-admin/css` there are 19 matches for `.mobile` and 13 for `.ios`. I
 did not look at those in detail, but probably most of them can be
 converted to use media queries. Adding `mobile` class to body might be
 required for backwards compatibility reasons, but this could be done with
 JavaScript just as well, we just need to determine what would be the
 features to test against. Plugins could have used the class for anything,
 at least in theory, so this could be hard.

 '''3. To print out meta viewport tags: 2 instances

 These are probably entirely unnecessary checks, those tags won't harm non-
 mobile browsers.

 '''4. Related to upload capabilities: 4 instances

 Some of these might be not relevant anymore, since they refer to old
 versions of iOS.

 '''5. Related to which editor features are enabled: 5 instances

 Editor's expandability, distraction free writing and help buttons are set
 based on is_wp_mobile. Also used to detect whether rich editing should be
 enabled.

 '''6. To load jQuery UI Touch Punch: 6 instances

 jQuery UI Touch Punch is a library that makes jQuery UI components to
 react to touch events. It is used to make meta boxes and other elements
 draggable, maybe something else. There are ways to detect touch
 capabilities on the client, but nothing 100% reliable. Probably better
 than user agent based though.

 '''7. For video on the about page: 2 instances

 This is for the streamlined updates animation in 4.6, not for the 4.6 main
 video. Probably used because there is no autoplay on iOS for video and
 that animation is not something you want to press play for and watch
 fullscreen. iOS 10 will allow silent autoplay and inline video, so that
 would work in the future without mobile detection if there are similar
 needs in the future. Not sure about Android though.

 '''8. Customizer: 4 instances

 `class-wp-customize-manager.php` and `theme.php` set some variables for
 mobile and ios to pass them to JavaScript. I found only one instance that
 uses those: customizer widgets do similar autofocus that category #1
 instances do. There could be more uses for these and themes could use
 these variables as well.

 '''9. Login shake: 1 instance

 Need to investigate why this is not enabled for mobile devices. Maybe the
 animation was not smooth enough back then?

 #

 All of those might require a different approach. Should there be a ticket
 for each of those categories with individual patches or should there be
 one giant patch within this ticket?

 Related: browser globals (`$is_lynx`, `$is_edge`, `$is_chrome`, etc.) are
 also determined from the `USER_AGENT` header and are just as evil. I hope
 no-one is using them to detect Netscape 4 anymore for example. This
 definitely is a topic for another ticket though.

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Ticket URL: <https://core.trac.wordpress.org/ticket/33704#comment:2>
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