Miscellaneous commands for HTML effects

 

The html package, through the L^ATEX input file html.sty, and its Perl counterpart html.perl, implements several new commands that are intended entirely for effects within the produced HTML files. In L^ATEX these commands, their arguments, and any optional arguments are completely ignored.

   

  
\htmlrule and \htmlrule*

One such device provided by html.sty, is the \htmlrule command. This puts a horizontal rule into the HTML file only; being ignored in the .dvi version. It is useful to provide extra visual separation between paragraphs, without creating a new HTML page, such as might warrant extra vertical space within the printed version.

     
^97.1
Much variation can be obtained in the horizontal rule that is produced, using extended forms of the \htmlrule command:

\htmlrule
\htmlrule*
\htmlrule[ <attribs>]
\htmlrule*[ <attribs>]

Whereas a ``break'' tag <BR> normally precedes the <HR> generated by the \htmlrule command, this break is omitted when using the \htmlrule* variant.

Furthermore, the optional argument <attribs> can be used to specify attributes for both the <HR> and <BR> tags. More specifically, <attribs> should be a list of attribute-names and/or key-value pairs <key>= <value> separated by spaces or commas. This list is parsed to extract those attributes applicable to the <HR> tag, and those applicable to the <BR> (with the unstarred variant).

Using HTML 3.2, this allows variations to be specified for:

• the (vertical) thickness of the horizontal line in pixels: SIZE= <num>;
• the (horizontal) width of the line in pixels or points: WIDTH= <width>;
• alignment: WIDTH="..." taking left, right or center;
• removal of the shadowed effect NOSHADE;
• positioning of the rule with respect to text-flows: CLEAR="..." taking left, all, right or none.
  

Some examples of these effects appear on this page.
^97.1

 

  
\strikeout{ <text>}

^97.1
With this command the <text> is processed as normal in the HTML version, then placed between <STRIKE>...</STRIKE> tags. Thus a horizontal line should be drawn through the middle of the <text>.
Currently the command and the <text> are ignored in the L^ATEX version.
^97.1

 

  
\tableofchildlinks

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As an extra aid to navigation within a long page, containing several (sub)subsections or deeper levels of sectioning, there is the \tableofchildlinks command. This does not generate anything new, for a table of the child links on or from a page is generated automatically by L^ATEX2HTML.

However if this command, or its variant \tableofchildlinks*, occurs within the source code to appear on a particular HTML page, then the child-links table will be placed at that point where the command occurs. Normally a break tag <BR> is inserted to separate the table of child-links from the surrounding text. The \tableofchildlinks* omits this extra break when it would result in too much space above the table.

For example throughout this section of the manual, all subsections in which several explicit commands have been discussed have their child-links table placed at the top of the page, using \tableofchildlinks*. This helps to quickly find the description of how the commands are used.
^97.1

 

  
\htmlinfo

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Normally an ``About this document...'' page is created at the end of the HTML document, containing technical information about how the document was created, by whom, or any other information contained in the $INFO variable. This information can be made to appear at any other place within the document by specifying \htmlinfo at the desired place in the source. For example, the information may be best suited for the title-page.

The variant \htmlinfo* places the information, but leaves out the standard ``About this document...'' header. Instead the \htmlhead command can be used to place an alternative heading, prior to the \htmlinfo* command. Neither this heading nor the $INFO contents appears in the L^ATEX typeset version.
^97.1

 

  
\bodytext{ <options>}

^96.1g
The text and background colors, and colors for the text of hypertext links can be set on an HTML page by giving appropriate attributes with the <BODY ...> tag. This is particularly easy to do using the \bodytext command, which simply inserts the <code> as the desired list of attributes.

 
Warning: Any previous settings for the <BODY ...> tag are discarded. Furthermore no checking is done to verify whether the given <options> indeed contains a list of attributes and values valid for the <BODY ...> tag.
When using \bodytext you are assumed to know precisely what you are doing!

Other packages contain commands which alter the contents of the <BODY ...> tag; notably the color.perl implementation of L^ATEX's color package, and the (prototype) frames package, by   Martin Wilck and   Ross Moore. In both these packages the requested information is checked for validity as an attribute within the <BODY ...> tag.
^96.1g

 

  
\htmlbody{ <options>}

^97.1
This is similar to the \bodytext command, except that it adds the value of an attribute, or allows an existing value to be changed. Thus it can be used to alter just a single one of the text and background colors, colors for the text of hypertext links or add a background pattern. The <options> are given as key-value pairs; some checking is done to ensure the validity of the attributes whose values are being set.
^97.1

 

  
\htmlbase{ <URL>}

^96.1g
This specifies that the given <URL> be included in the <HEAD> section of each HTML page via a tag: <BASE HREF=" <URL>".
Such a feature is particularly useful...

• when preparing a document whose final location may be different from where it was created; By making all internal references be relative (to the the provided <URL>), a whole directory tree containing the document and all its subparts can be moved to elsewhere. A single edit in each HTML file produces the complete document intact at the new location.
• by allowing just single page to be copied to another location, but act as if it were part of the original document (provided this is accessible across the Web). Relative URLs within the copied page are relative to the base <URL>, rather than relative to the new location.
• Other uses for this feature are likely to become apparent.

^96.1g

   

  
\HTMLset{ <which>}{ <value>} and \HTMLsetenv{ <which>}{ <value>}

^97.1
The \HTMLset command provides a mechanism whereby an arbitrary Perl variable can be assigned a value dynamically, during the L^ATEX2HTML processing. A variable having name `$ <which>' is assigned the specified <value>, overwriting any value that may exist already. The \HTMLsetenv is for the same purpose, but it is expanded in order as if it were an environment, rather than a command.

Warning: This is intended for Perl programmers only. Use this command at your own risk!
^97.1

     

  
\latextohtml

^97.1
expands to the name L^ATEX2HTML, of this translator. Commands for parts of names of important L^ATEX packages are also included with L^ATEX2HTML: e.g. TEX, L^ATEX, A_MS, X_Y. (This is to make it easy to refer to these products, in a consistent way within the HTML pages; you may still need L^ATEX definitions for the typeset version.)
^97.1