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

Article
04/30/2007

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

Attribute	Description
match	Required String attribute. Specifies a .NET Framework regular expression that is tested against the with attribute. If omitted, the match is assumed successful.
with	Required String attribute. Specifies the .NET Framework regular expression or string to search. If omitted, the string that is specified by the use element is used.

match

Required String attribute.

Specifies a .NET Framework regular expression that is tested against the with attribute. If omitted, the match is assumed successful.

with

Required String attribute.

Specifies the .NET Framework regular expression or string to search. If omitted, the string that is specified by the use element is used.

Child Elements

None.

Parent Elements

Element	Description
configuration	Specifies the required root element in every configuration file that is used by the common language runtime and the .NET Framework applications.
system.web	Specifies the root element for the ASP.NET configuration settings in a configuration file and contains configuration elements that configure ASP.NET Web applications and control how the applications behave.
browserCaps	Specifies the settings of supported browsers and the capabilities for the browsers. The browserCaps element can be updated as required to specify new browsers and capabilities. For a list of valid browser properties, see HttpBrowserCapabilities.
filter	Specifies a list of search strings that allow you to apply individual settings to specific browser definitions.

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

Configuration section handler	HttpCapabilitiesSectionHandler
Configuration member	Browsers
Configurable locations	Machine.config Root-level Web.config Application-level Web.config Virtual or physical directory–level Web.config
Requirements	Microsoft Internet Information Services (IIS) version 5.0, 5.1, or 6.0 The .NET Framework version 2.0 (deprecated), 1.1, or 1.0 Microsoft Visual Studio 2003 or Visual Studio 2005

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

Attributes and Elements

Attributes

Child Elements

Parent Elements

Remarks

Default Configuration

Example

Element Information

See Also

Tasks

Reference

Concepts

Other Resources

Additional resources