Class: Rack::MobileDetect
- Inherits:
-
Object
- Object
- Rack::MobileDetect
- Defined in:
- lib/rack/mobile-detect.rb
Overview
Full project at github.com/talison/rack-mobile-detect
Rack::MobileDetect detects mobile devices and adds an X_MOBILE_DEVICE header to the request if a mobile device is detected. The strategy for detecting a mobile device is as follows:
-
Search for a ‘targeted’ mobile device. A targeted mobile device
is a mobile device you may want to provide special content to because it has advanced capabilities - for example an iPad, iPhone or Android device. Targeted mobile devices are detected via a Regexp applied against the HTTP User-Agent header.
By default, the targeted devices are iPhone, Android, iPad and iPod. If a targeted device is detected, the token match from the regular expression will be the value passed in the X_MOBILE_DEVICE header, i.e.: X_MOBILE_DEVICE: iPhone
-
Search for a UAProf device. More about UAProf detection can be
found here: www.developershome.com/wap/detection/detection.asp?page=profileHeader
If a UAProf device is detected, the value of X_MOBILE_DEVICE is simply set to ‘true’.
-
Look at the HTTP Accept header to see if the device accepts WAP
content. More information about this form of detection is found here: www.developershome.com/wap/detection/detection.asp?page=httpHeaders
Any device detected using this method will have X_MOBILE_DEVICE set to ‘true’.
-
Use a ‘catch-all’ regex. The current catch-all regex was taken
from the mobile-fu project. See: github.com/brendanlim/mobile-fu
Any device detected using this method will have X_MOBILE_DEVICE set to ‘true’.
If none of the detection methods detected a mobile device, the X_MOBILE_DEVICE header will be absent.
Note that Rack::MobileDetect::X_HEADER holds the string ‘X_MOBILE_DEVICE’ that is inserted into the request headers.
Usage: use Rack::MobileDetect
This allows you to do mobile device detection with the defaults.
use Rack::MobileDetect, :targeted => /SCH-w*$|[Bb]lackerryw*/
In this usage you can set the value of the regular expression used to target particular devices. This regular expression captures Blackberry and Samsung SCH-* model phones. For example, if a phone with the user-agent: ‘BlackBerry9000/4.6.0.167 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/102’ connects, the value of X_MOBILE_DEVICE will be set to ‘BlackBerry9000’
use Rack::MobileDetect, :catchall => /mydevice/i
This allows you to limit the catchall expression to only the device list you choose.
See the unit test source code for more info.
Author: Tom Alison (tom.alison at gmail.com) License: MIT
Constant Summary collapse
- X_HEADER =
'X_MOBILE_DEVICE'
Instance Method Summary collapse
-
#call(env) ⇒ Object
Because the web app may be multithreaded, this method must create new Regexp instances to ensure thread safety.
-
#check_for_redirect(device) ⇒ Object
Checks to see if any redirect options were passed in and returns the appropriate redirect or nil (if no redirect requested).
-
#initialize(app, options = {}) ⇒ MobileDetect
constructor
Users can pass in a :targeted option, which should be a Regexp specifying which user-agent agent tokens should be specifically captured and passed along in the X_MOBILE_DEVICE variable.
Constructor Details
#initialize(app, options = {}) ⇒ MobileDetect
Users can pass in a :targeted option, which should be a Regexp specifying which user-agent agent tokens should be specifically captured and passed along in the X_MOBILE_DEVICE variable.
The :catchall option allows specifying a Regexp to catch mobile devices that fall through the other tests.
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# File 'lib/rack/mobile-detect.rb', line 105 def initialize(app, = {}) @app = app # @ua_targeted holds a list of user-agent tokens that are # captured. Captured tokens are passed through in the # environment variable. These are special mobile devices that # may have special rendering capabilities for you to target. @regex_ua_targeted = [:targeted] || /iphone|android|ipod|ipad/i # Match mobile content in Accept header: # http://www.developershome.com/wap/detection/detection.asp?page=httpHeaders @regex_accept = /vnd\.wap/i # From mobile-fu: http://github.com/brendanlim/mobile-fu @regex_ua_catchall = [:catchall] || Regexp.new('palm|blackberry|nokia|phone|midp|mobi|symbian|chtml|ericsson|minimo|' + 'audiovox|motorola|samsung|telit|upg1|windows ce|ucweb|astel|plucker|' + 'x320|x240|j2me|sgh|portable|sprint|docomo|kddi|softbank|android|mmp|' + 'pdxgw|netfront|xiino|vodafone|portalmmm|sagem|mot-|sie-|ipod|up\\.b|' + 'webos|amoi|novarra|cdm|alcatel|pocket|ipad|iphone|mobileexplorer|' + 'mobile', true) # A URL that specifies a single redirect-url for any device @redirect_to = [:redirect_to] # A mapping of devices to redirect URLs, for targeted devices @redirect_map = [:redirect_map] end |
Instance Method Details
#call(env) ⇒ Object
Because the web app may be multithreaded, this method must create new Regexp instances to ensure thread safety.
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# File 'lib/rack/mobile-detect.rb', line 135 def call(env) device = nil user_agent = env.fetch('HTTP_USER_AGENT', '') # First check for targeted devices and store the device token device = Regexp.new(@regex_ua_targeted).match(user_agent) # Fall-back on UAProf detection # http://www.developershome.com/wap/detection/detection.asp?page=profileHeader device ||= env.keys.detect { |k| k.match(/^HTTP(.*)_PROFILE$/) } != nil # Fall back to Accept header detection device ||= Regexp.new(@regex_accept).match(env.fetch('HTTP_ACCEPT','')) != nil # Fall back on catch-all User-Agent regex device ||= Regexp.new(@regex_ua_catchall).match(user_agent) != nil if device device = device.to_s env[X_HEADER] = device redirect = check_for_redirect(device) if redirect path = Rack::Utils.unescape(env['PATH_INFO']) return [301, {'Location' => redirect}, []] if redirect && path !~ /^#{redirect}/ end end @app.call(env) end |
#check_for_redirect(device) ⇒ Object
Checks to see if any redirect options were passed in and returns the appropriate redirect or nil (if no redirect requested)
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# File 'lib/rack/mobile-detect.rb', line 169 def check_for_redirect(device) # Find the device-specific redirect in the map, if exists return @redirect_map[device] if @redirect_map && @redirect_map.has_key?(device) # Return global redirect, or nil return @redirect_to end |