User Agent (Expression Function)

Purpose

The User Agent function (USER_AGENT) returns the user agent string from the browser. It is commonly used to present different content to end users based on the browser they are using. This is sometimes necessary to work around bugs or feature limitations in certain browsers while providing the best possible experience to users using browsers without the bug or limitation. This function could also be used to limit, modify, or remove functionality when a user is accessing an application from a mobile browser. Generally this feature should not be used to style the application differently for different browsers, as that should be handled using CSS via the CSS Style Builder.

Parameters

The User Agent function has one optional parameter:

Piece

Allowed Inputs: browser, browser_version, mobile, tablet, os, os_version, comment

To return the full user agent string as reported by the browser leave this parameter empty. To pull a piece of the user agent string use one of the supported parameters. Depending on what the browser reports any or all of the pieces may be missing. Possible return values for the pieces are:

  • browser - Chrome, IE, Safari, Firefox, Opera, etc
  • browser_version - “28.0”, “11.0”, etc
  • mobile - “1” or “”
  • tablet - “1” or “”
  • os - “Win8.1”,“Win7”, “WinVista”, “WinXP”, “Win2000”, “MacOSX”, “Linux”, “Android”, “iOS”
  • os_version - unknown, “10”, “6.1”, etc
  • comment - “Mobile Safari”, “Chrome 18.0”, “IE 11.0”, etc

Output

The output of the User Agent function is a string.

Example

If the user agent reported by the browser was “Mozilla/5.0 (Linux; Android 4.0.4; Galaxy Nexus Build/IMM76B) AppleWebKit/535.19 (KHTML, like Gecko) Chrome/18.0.1025.133 Mobile Safari/535.19”, the output of:

  • USER_AGENT() would return “Mozilla/5.0 (Linux; Android 4.0.4; Galaxy Nexus Build/IMM76B) AppleWebKit/535.19 (KHTML, like Gecko) Chrome/18.0.1025.133 Mobile Safari/535.19”
  • USER_AGENT(“browser”) would return “Chrome”
  • USER_AGENT(“broser_version”) would return “18.0”
  • USER_AGENT(“mobile”) would be “1”
  • USER_AGENT(“tablet”) would be “”
  • USER_AGENT(“os”) would be “Android”
  • USER_AGENT(“os_version”) would be “4.0”
  • USER_AGENT(“comment”) would be “Chrome 18.0”
expression function - user agent.txt · Last modified: 2016/09/14 14:19 (external edit)
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