Filtering of tag-based static URLs

WebSEAL uses a set of default rules to scan for (or filter) tag-based static URLs contained in pages that are responses to client requests. This default filtering mechanism examines static URLs located within tag-based content (such as HTML or XML).

The term "filtering" is used to indicate WebSEAL's process of scanning Web documents for absolute and server-relative links and modifying the links to include junction information.

An important requirement for this mechanism is that the URLs must be visible to WebSEAL. For example, tag-based content filtering cannot handle URLs that are dynamically generated on the client-side.

When the preserve-base-href2 option is also set to "yes" WebSEAL only performs the minimum filtering of the BASE HREF tag necessary to insert the WebSEAL host and junction names. The value of the preserve-base-href2 option impacts the processing of any BASE HREF tags that are missing the trailing slash.

REMINDER: This option has no effect if preserve-base-href is set to "no".

Example 5 (BASE HREF that contains no trailing slash matches a junctioned server)

WebSEAL server: www.webseal.com

The following junction was created:

server task webseal-server create -tcp -h www.example.com /jct

HTML before filtering

NOTE: There is no trailing slash in the BASE HREF value:

<HTML>
<HEAD>
<BASE HREF="http://www.example.com"> 
</HEAD>
<BODY>
<A HREF="index.html">index.html</A>
</BODY>
</HTML>

HTML after filtering when preserve-base-href2 is set to "no".

NOTE: WebSEAL maps the HREF to /jct and then eliminates the /jct because there is no trailing slash.

<HTML>
<HEAD>
<BASE HREF="http://www.webseal.com/"> 
</HEAD>
<BODY>
<A HREF="index.html">index.html</A>
</BODY>
</HTML>

HTML after filtering when preserve-base-href2 is set to "yes".

NOTE: WebSEAL performs the minimum filtering of the BASE HREF tag necessary to insert the WebSEAL host and junction names. The missing trailing slash does not cause the last component in the base HREF URL to be stripped.

<HTML>
<HEAD>
<BASE HREF="http://www.webseal.com/jct/"> 
</HEAD>
<BODY>
<A HREF="index.html">index.html</A>
</BODY>
</HTML>

This section contains the following topics: