showifnum
Description
This command has been implemented primarily with SGML/XML type attributes in mind. <?showifnum> permits the conditional processing of a show string, the condition being the presence of a defined attribute with a numerical value (0-9) on the SGML/XML element. When the specified condition has been met the command will show the value of the attribute.
Example 387. Use <?showifnum> command for conditional processing of the date
This is an example of <?showifnum> used to produce different formats of dates. For example, if the tag <date> contains<?showifnum "id" Publication date $^fred#^>, the following references to <date> will give the corresponding output:
<date id=1998>
Output: Publication date 1998
<date id="98 Dec">
Output: Publication date 98 Dec
<date>
Output: (nothing)
<date id="Dec 98">
Output: (nothing)
If the tag <date> contains <?showifnum !"id" Publication date $^fred#^, the following references to <date> will give the corresponding output:
<date id=1998>
Output: (nothing)
<date id="98 Dec">
Output: (nothing)
<date>
Output: Publication date 1998
<date id="Dec 98">
Output: Publication date 98 Dec
Syntax
<?showifnum !:L? name:s showstring:sw>
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!
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Use the opposite condition: instead of show if defined with a numerical value , use show if name NOT defined or show if value is not numerical.
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name
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Specify that the name of the attribute for which to test must be present
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showstring
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Any applicable showstring.
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For more information, see Reference Chapter: Showstrings.