case Element for filter for browserCaps (ASP.NET Settings Schema) 

Allows pattern matching to stop after processing the first successful match out of a number of alternatives.

Note

Using the browserCaps element in the Web.config file to define browsers is deprecated in the .NET Framework 2.0; however, it is still supported. The data in this element is merged with the information from the browser definition files (.browser) that are located in the machine-level %SystemRoot%\Microsoft.NET\Framework\version\CONFIG\Browsers folder and any existing application-level App_Browsers folders. For more information, see Browser Definition File Schema (browsers Element).

<case 
   match="regex expression"
   with="regex expression"
>
   [browser capability assignments, filter elements, case elements]
</case>

Attributes and Elements

The following sections describe attributes, child elements, and parent elements.

Attributes

Child Elements

None.

Parent Elements

Remarks

The case element allows pattern matching to stop after processing the first successful match out of a number of alternatives.

All filter and case elements can contain assignments and other filter and case elements. The difference between case and filter groups is this: after a filter group is evaluated, execution continues with the statement after the group, but after a case group is successfully matched and evaluated, execution skips to the end of the enclosing group.

Default Configuration

In the .NET Framework version 2.0, the case element is not configured because the browserCaps element is deprecated in favor of using browser definition files to specify supported browsers and the capabilities for the browsers. For more information, see Browser Definition File Schema (browsers Element).

In the .NET Framework versions 1.0 and 1.1, the default case elements that are configured in the Machine.config file are too numerous to list here. For updates to the browser data go to http://www.cyscape.com/browsercaps. Periodic device updates replace this browser capabilities section.

Example

The following code example demonstrates how to parse the User-Agent HTTP header for any version of Microsoft Internet Explorer, as long as the format of the User-Agent string remains approximately unchanged.

The example makes use of the .NET Framework Regular Expressions and the ability of regular expressions to capture subexpressions in order to move version numbers directly from the User-Agent string to the browserCaps element.

The file specifies name/value pairs in the form of assignment statements, which is similar to Microsoft Internet Information Services (IIS) browscap.ini files. For example, the line "browser=IE" sets the value of the browser field to the string "IE".

<configuration>
   <browserCaps>
      <result type="System.Web.HttpBrowserCapabilities, System.Web"/>
      <use var="HTTP_USER_AGENT"/>
      browser=Unknown
      version=0.0
      majorversion=0
      minorversion=0
      frames=false
      tables=false
      cookies=false
      backgroundsounds=false
      <filter>
         <case match="^Mozilla[^(]*\(compatible; MSIE 
            (?'ver'(?'major'\d+)(?'minor'\.\d+)(?'letters'\w*))
            (?'extra'.*)">
            browser=IE
            version=${ver}
            majorver=${major}
            minorver=${minor}
            <case match="^2\." with="%{version}">
               tables=true
               cookies=true
               backgroundsounds=true
               <case match="2\.5b" with="%{version}">
                  beta=true
               </case>
            </case>
         </case>
      </filter>
   </browsercaps>
</configuration>

Element Information

See Also

Tasks

How to: Detect Browser Types in ASP.NET Web Pages
How to: Configure Specific Directories Using Location Settings
How to: Lock ASP.NET Configuration Settings

Reference

filter Element for browserCaps (ASP.NET Settings Schema)
browserCaps Element (ASP.NET Settings Schema)
system.web Element (ASP.NET Settings Schema)
configuration Element (General Settings Schema)
result Element for browserCaps (ASP.NET Settings Schema)
use Element for browserCaps (ASP.NET Settings Schema)
Browser Definition File Schema (browsers Element)
System.Configuration
System.Web.Configuration
HttpCapabilitiesSectionHandler
Browsers

Concepts

ASP.NET Web Server Controls and Browser Capabilities
ASP.NET Configuration File Hierarchy and Inheritance
Securing ASP.NET Configuration
ASP.NET Configuration Scenarios

Other Resources

General Configuration Settings (ASP.NET)
ASP.NET Configuration Settings
Configuring ASP.NET Applications
ASP.NET Configuration API