If a tag is not performing the expected function, the tag may be malformed or may have been altered by an HTML editor. The following steps can help isolate this problem:
This indicates that BIS is not recognizing the tag. Check the spelling of the tag and be sure that the HTML editor did not split the tag across multiple lines-tags may not contain line break characters or span lines (you'll have to use the browser's View > Source to examine the raw HTML to be sure). On UNIX, enabling tracing (see below) and setting the BISStencilDebug configuration option will cause the generation of a trace message with the reason why a tag was rejected.
If a malformed tag is embedded in an HTML comment (see the example in the Rendering Tags section), the tag may fail to render but not be visible in the rendered output. To see such tags, use your web browser's View > Source command. Tags should never appear in the raw HTML that is sent to the web browser.
Enable tracing and examine the trace output. If you have access to the .srf file, to quickly enable tracing, insert this tag after the Handler tag:
{{ Trace(start,page) }}
Then request the page using your web browser. This will cause trace output to be appended to the end of the current page. The trace output indicates when most tags are rendered and the results of the rendering.
On BIS/IIS, to direct trace output to a file, replace page with file (or specify both using page,file). This will direct all trace output for the session into a file in the server's temporary directory (normally C:\Windows\Temp), or the directory specified in the trace dir= parameter. If you use this type of tracing, be sure to occasionally delete these files from the temporary directory.
The trace files use the following naming convention:
BIS-ssss-trace.txt
Where ssss are the initial characters from the session identifier. The first four non-slash characters of the session identifier are always used; if a file of that name already exists, BIS will continue to add characters from the session ID until the filename is unique.
On UNIX, trace output is directed to a file if tracing is enabled. A separate trace file is created for each session and is placed in the UNIX /tmp directory unless the BISTraceDirectory configuration option is specified or redirected with the trace dir= parameter. So on UNIX, Trace(start) is sufficient to create a trace file.
Note that on UNIX, the BISMasterTrace configuration option must be enabled before any tracing can occur. See Configuring Apache for details about setting or clearing this option.
Tracing is the most useful of the above techniques and should be enabled during the development process.