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899 lines
35 KiB
HTML
899 lines
35 KiB
HTML
<HTML>
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<HEAD>
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<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1">
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<META NAME="Author" CONTENT="Kipp E.B. HIckman">
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<META NAME="GENERATOR" CONTENT="Mozilla/4.03 [en] (WinNT; I) [Netscape]">
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<TITLE>HTML</TITLE>
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<BASE HREF="file:///s|/ns/xena/htmlpars/testhtml/">
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</HEAD>
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<BODY TEXT="#000000" BGCOLOR="#FFFFFF" LINK="#FF0000" VLINK="#800080" ALINK="#0000FF">
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<H2>
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HTML</H2>
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This documents describes the complete handling of HTML in magellan. The
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document covers the parsing process - how HTML is lexically analysized
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and then interprted. After the parsing process is discussed we give a detailed
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analysis of each HTML tag and the attributes that are supported, the values
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for the attributes and how the tag is treated by magellan.
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<H2>
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Parsing</H2>
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HTML is tokenized by an HTML scanner. The scanner is fed unicode data to
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parse. Stream converters are used to translate from various encodings to
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unicode. The scanner separates the input stream into tokens which consist
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of:
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<UL>
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<LI>
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text</LI>
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<LI>
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tags</LI>
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<LI>
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entities</LI>
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<LI>
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script-entities</LI>
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<LI>
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comments</LI>
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<LI>
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conditional comments</LI>
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</UL>
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The HTML parsing engine uses the HTML scanner for lexical anlaysis. The
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parsing engine operates by attacking the input stream in a set of well
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defined steps:
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<UL>
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<LI>
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The parser processes the head portion of the document first, without emitting
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any output. This is done to discover a few special features of html:</LI>
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<UL>
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<LI>
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The parser processes META tags looking for META TARGET</LI>
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<LI>
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The parser processes META tags looking for META tags which affect the character
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set. Nav4 handles the very first character set defining meta tag (all others
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are ignored) by reloading the document with the proper character conversion
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module inserted into the stream pipeline.</LI>
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</UL>
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<LI>
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After the head portion is processed the parser then proceeds to process
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the body of the document</LI>
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</UL>
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<H3>
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Tag Processing</H3>
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Tags are processed by the parser by locating a <B>"tag handler"</B> for
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the tag. The HTML parser serves as the tag handler for all of the builtin
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tags documented below. Tag attribute handling is done during translation
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of tags into content. This mapping translates the tag attributes into content
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data and into style data. The translation to style data is documented below
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by indicating the mapping from tag attributes to their CSS1 (plus extensions)
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equivalents.
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<H3>
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Special Hacks</H3>
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The following list describes hacks added to the magellan parsing engine
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to deal with navigator compatability. These are just the parser hacks,
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not the layout or presentation hacks. Most hacks are intriduced for HTML
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syntax error recovering. HTML doesn't specify much how to handle those
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error conditions. Netscape has made big effort to render pages with non-prefect
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HTML. For many reasons, new browsers need to keep compatible in thsi area.
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<UL>
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<LI>
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Entities can be used as escape in quoted string. For value string in name-value
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pair, see <A HREF="../testhtml/quote001.html">compatibility test
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quote001.html</A>. Test line 70 shows that an entity quote at the begining
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means the value is NOT quoted. Test line 90 shows that if the value is
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started with a quote, then an entity quote does NOT terminate the value
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string.</LI>
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<LI>
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Wrapping tags are special tags such as title, textarea, server, script,
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style, and etc.. The comment in ns\lib\libparse\pa_parse.c says:</LI>
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<BR> /*
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<BR> * These tags are special in that, after opening one of
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them, all other tags are ignored until the matching
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<BR> * closing tag.
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<BR> */
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<BR>During the searching of an end tag, comments and quoted strings are
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observed. see <A HREF="../testhtml/title01.html">compatibility test title01.html</A>.
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6.0 handles comments now, need to add quoted string.
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<LI>
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If a <tr> or <td> tag is seen outside any <table> scope, it is
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ignored. see <A HREF="../testhtml/table110.htm">compatibility test table110.htm</A>.</LI>
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<LI>
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<FONT COLOR="#000000">In case of table in table but not in cell, table
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tags before the last table tag are ignored. We found this problem in some
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Netscape public pages, see bug #85118. For example, <table> <table
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border> .....,or <table> <tr> <table border>..., the table
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will be displayed with border. </FONT> <A HREF="../testhtml/table201.html">compatibility
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test table201.html</A>. There table and tr tags are buffered for this recovery.
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When a TD or CAPTION tag is open, the buffer is flushed out, because we
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cannot buffer contents of TD or CAPTION for performance and memory constrains.
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They are subdoc's and can be very big. If we see a <table> outside cell
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after previous table is flushed out, the new <table> tag is ignored.
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Nav4.0 can discard previous table in such case. <A HREF="../testhtml/tableall.html">tableall.html
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</A>is the index for table test cases.</LI>
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<LI>
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Caption is not a commonly used feature. In Nav4.0, captions can be anywhere.
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For Captions outside cells, the first one takes effect. For captions inside
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cells, the last one takes effect, and they also close TD and TR. In 6.0,
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caption is limited to the standard position: after <table>. Captions
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in other places are ignored, their contents are treated as text. See test
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case table05a.html to table05o.html.</LI>
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<LI>
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<FONT COLOR="#000000">For <table> <tr> <tr>, the first <tr>
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takes effect.</FONT></LI>
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<LI>
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The nav4 parser notices when it hits EOF and it's in the middle of scanning
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in a comment. When this happens, the parser goes back and looks for an
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improperly closed comment (e.g. a simple > instead of a -->). If it finds
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one, it reparses the input after closing out the comment.</LI>
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<LI>
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<FONT COLOR="#FF0000">XXX Brendan also pointed out that there is something
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similar done for tags, but I don't recall what it is right now.</FONT></LI>
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<LI>
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<FONT COLOR="#000000">When Nav4.0 sees the '<' sign, it searchs for
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'>', observing quoted values. If it cannot find one till EOF, the '<'
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sign is treated as text. In Xena 6.0, a limit is set for how far the '>'
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is searched. the default limit is 4096 char, and there is a API HTMLScanner.setMaxTagLength()
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to changed it. setting -1 means no limit, which is same as Nav4.0.</FONT></LI>
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</UL>
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<FONT COLOR="#FF0000">TODO:</FONT>
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<UL><FONT COLOR="#FF0000">Document the mapping of tag attributes into CSS1
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style, including any new "css1" attributes</FONT>
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<BR> </UL>
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<B>List of 6.0 features incompatible with 4.0</B>
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<UL>
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<LI>
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Navigator 4.0 value string is truncated at 82 characters. XENA60 limit
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is MAX_STRING_LENGTH = 2000.</LI>
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<BR> </UL>
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<HR WIDTH="100%">
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<H2>
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Tags (Categorically sorted)</H2>
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All line breaks are conditional. If the x coordinate is at the current
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left margin then a soft line break does nothing. Hard line breaks are ignored
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if the last tag did a hard line break.
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<P><B>divalign</B> = left | right | center | justify
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<BR><B>alignparam</B> = abscenter | left | right | texttop | absbottom
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| baseline | center | bottom | top | middle | absmiddle
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<BR><B>colorspec</B> = named-color | #xyz | #xxyyzz | #xxxyyyzzz | #xxxxyyyyzzzz
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<BR><B>clip</B> = [auto | value-or-pct-xy](1..4) (pct of width for even
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coordinates; pct of height for odd coordinates)
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<BR><B>value-or-pct = </B>an integer with an optional %; ifthe percent
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is present any following characters are ignored!
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<BR><B>coord-list</B> = <FONT COLOR="#DD0000">XXX</FONT>
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<BR><FONT COLOR="#000000"><B>whitespace-strip</B> = remove leading and
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trailing and any embedded whitespace that is not an actual space (e.g.
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newlines)</FONT>
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<H1>
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Head objects:</H1>
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<B>TITLE</B>
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<UL>The TITLE tag is a container tag whose contents are not HTML. The contents
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are pure text and are processed by the parser until the closing tag is
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found. There are no attributes on the tag and any whitespace present in
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the tag is compressed down with leading and trailing whitespace eliminated.
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The first TITLE tag found by the parser is used as the document's title
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(subsequent tags are ignored).</UL>
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<B>BASE</B>
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<UL>Sets the base element in the head portion of the document. Defines
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the base URL for <FONT COLOR="#DD0000">all</FONT>? links in the document.
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<BR>Attributes:
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<UL><B>HREF</B>=url [This is an absolute URL]
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<BR><B>TARGET</B>=string [must start with XP_ALPHA|XP_DIGIT|underscore
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otherwise nav4 ignores it]</UL>
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</UL>
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<B>META</B>
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<UL>Can define several header fields (content-encoding, author, etc.)
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<BR>Attributes:
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<UL><B>REL</B>=SMALL_BOOKMARK_ICON|LARGE_BOOKMARK_ICON
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<UL><B>SRC</B>=string</UL>
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<B>HTTP-EQUIV</B>="header: value"
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<UL><B>CONTENT</B>=string</UL>
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</UL>
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HTTP-EQUIV values (from libnet/mkutils.c NET_ParseMimeHeader):
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<UL>ACCEPT-RANGES
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<BR>CONTENT-DISPOSITION
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<BR>CONTENT-ENCODING
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<BR>CONTENT-RANGE
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<BR>CONTENT-TYPE [ defines character set only ]
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<BR>CONNECTION
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<BR>DATE
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<BR>EXPIRES
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<BR>EXT-CACHE
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<BR>LOCATION
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<BR>LAST-MODIFIED
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<BR>LINK
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<BR>PROXY-AUTHENTICATE
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<BR>PROXY-CONNECTION
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<BR>PRAGMA
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<BR>RANGE
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<BR>REFRESH
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<BR>SET-COOKIE
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<BR>SERVER
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<BR>WWW-AUTHENTICATE
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<BR>WWW-PROTECTION-TEMPLATE
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<BR>WINDOW-TARGET</UL>
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Style sheets and HTML w3c spec adds this:
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<UL>CONTENT-STYLE-TYPE [ last one wins; overrides header from server if
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any ]</UL>
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</UL>
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<B>LINK</B>
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<UL>List related resources. Used by extensions mechanism to find tag handlers.
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<FONT COLOR="#0000FF">/LINK == LINK!</FONT>
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<BR>Attributes:
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<UL><B>REL</B>=FONTDEF
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<UL><B>SRC</B>=url</UL>
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<B>REL</B>=STYLESHEET [ If MEDIA param is defined it must ==nc screen ]
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<UL><B>LANGUAGE</B>=LiveScript|Mocha|JavaScript1.1|JavaScript1.2
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<BR><B>TYPE</B>="text/javascript" | "text/css"
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<BR><B>HREF</B>=url
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<BR><B>ARCHIVE</B>=url
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<BR><B>CODEBASE</B>=url
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<BR><B>ID</B>=string
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<BR><B>SRC</B>=url</UL>
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</UL>
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Note: HREF takes precedence over SRC in nav4.</UL>
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<B>HEAD</B>
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<UL>/HEAD clears the "in_head" flag (but leaves the "in_body" flag alone.
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<BR>Text in head clears in_head, and set in_body true, just as if the author
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forgot the /HEAD tag.
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<BR>Attributes: none</UL>
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<B>HTML</B>
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<UL>Ignored.
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<BR>Attributes: none</UL>
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<B>STYLE</B>
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<UL>Allowed anywhere in the document. Note that entities are not parsed
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in the style tag's content.
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<BR>Attributes:
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<UL><B>LANGUAGE</B>=LiveScript|Mocha|JavaScript1.1|JavaScript1.2
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<BR><B>TYPE</B>="text/javascript" | "text/css"
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<BR><B>HREF</B>=url
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<BR><B>ARCHIVE</B>=url
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<BR><B>CODEBASE</B>=url
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<BR><B>ID</B>=string
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<BR><B>SRC</B>=url</UL>
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</UL>
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<B>FRAMESET</B>
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<UL>Frameset with rows=1 and cols=1 is ignored.
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<BR>Attributes:
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<UL><B>FRAMEBORDER</B>= no | 0 (zero) [default is no_edges=false]
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<BR><B>BORDER</B>= int [clamped: >= 0 && <= 100]
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<BR><B>BORDERCOLOR</B>= color
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<BR><B>ROWS</B>= pct-list
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<BR><B>COLS</B>= pct-list</UL>
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</UL>
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<B>FRAME</B>
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<UL>Border width of zero disables edges.
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<BR>Attributes:
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<UL><B>FRAMEBORDER</B>= no | 0 (zero) [default is framesets value]
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<BR><B>BORDER</B>= int [clamped; >= 0 && <= 100]
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<BR><B>BORDERCOLOR</B>= color
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<BR><B>NORESIZE</B>= true [default is false]
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<BR><B>SCROLLING</B>= yes | scroll | on | no | noscroll | off
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<BR><B>SRC</B>= url [clamped: prevent recursion by eliminating any anscestor
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references]
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<BR><B>NAME</B>= string
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<BR><B>MARGINWIDTH</B>= int (clamped: >= 1)
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<BR><B>MARGINHEIGHT</B>= int (clamped: >= 1)</UL>
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</UL>
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<B>NOFRAMES</B>
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<UL>Used when frames are disabled or for backrev browsers. Has no stylistic
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consequences.</UL>
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<H1>
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<HR WIDTH="100%">Body objects:</H1>
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<B>BODY</B>
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<UL>The tag is only processed on open tags and it is always processed.
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See ns\lib\layout\laytags.c, searching for "case P_BODY". During tag processing
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the in_head flag is set to false and the in_body flag is set to true. An
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attribute is ignored if the document already has that attribute set. Attributes
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can be set by style sheets, or by previous BODY tags. see <A HREF="../testhtml/head02.html">test
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head02.html</A>.
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<BR>Attributes:
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<UL><B>MARGINWIDTH</B>=int [clamped: >= 0 && < (windowWidth/2
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- 1)]
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<BR><B>MARGINHEIGHT</B>=int [clamped: >= 0 && < (windowHeight/2
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- 1)]
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<BR><B>BACKGROUND</B>=url
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<BR><B>BGCOLOR</B>=colorspec
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<BR><B>TEXT</B>=colorspec
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<BR><B>LINK</B>=colorspec
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<BR><B>VLINK</B>=colorspec
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<BR><B>ALINK</B>=colorspec
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<BR><B>ONLOAD, ONUNLOAD, UNFOCUS, ONBLUR, ONHELP</B>=script
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<BR><B>ID</B>=string</UL>
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</UL>
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<B>LAYER, ILAYER</B>
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<UL>Open layer/ilayer tag automaticly close out an open form if one is
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open. It does something to the soft linebreak state too.
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<BR>Attributes:
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<UL><B>LEFT</B>=value-or-pct (pct of <TT>right-left</TT> margin)
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<BR><B>PAGEX</B>=x (if no LEFT)
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<BR><B>TOP</B>=value-or-pct
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<BR><B>PAGEY</B>=y (if no TOP)
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<BR><B>CLIP</B>=clip
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<BR><B>WIDTH</B>=value-or-pct (pct of <TT>right-left</TT> margin)
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<BR><B>HEIGHT</B>=value-or-pct
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<BR><B>OVERFLOW</B>=string
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<BR><B>NAME</B>=string
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<BR><B>ID</B>=string
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<BR><B>ABOVE</B>=string
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<BR><B>BELOW</B>=string
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<BR><B>ZINDEX</B>=int [any value]
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<BR><B>VISIBILITY</B>=string
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<BR><B>BGCOLOR</B>=colorspec
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<BR><B>BACKGROUND</B>=url</UL>
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</UL>
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<B>NOLAYER</B>
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<UL>Container for content which is used when layers are disabled or unsupported.
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The content has no style consequences (though it could if somebody stuck
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in some CSS1 style rules for it).</UL>
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<B>P</B>
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<UL>Closes the paragraph. If the attribute is present then an alignment
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gets pushed on the alignment stack. All values are supported by nav4.
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<BR>Attributes:
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<UL><B>ALIGN</B>=divalign</UL>
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</UL>
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<B>ADDRESS</B>
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<UL>There are no attributes. ADDRESS closes out the open paragraph. The
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open tag does a conditional soft line break and then pushes a merge of
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the current style with italics enabled onto the style stack. The close
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always pop the style stack and also does a conditional soft line break.</UL>
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<B>PLAINTEXT, XMP</B>
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<UL>PLAINTEXT causes the remaining content to no longer be parsed. XMP
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causes the content to not parse entities or other tags. The XMP can be
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closed by it's own tag (on any boundary); PLAINTEXT is not closed (html3.2
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allows it to be closed). Both tags change the style to a fixed font of
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a</UL>
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<B>LISTING</B>
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<UL>Closes the paragraph. Does a hard line break on open and close. Open
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pushes a fixed width font style of a particular font size on the style
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stack. The close tag pops the top of the style stack.
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<BR>Attributes: none</UL>
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<B>PRE</B>
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<UL>Closes the paragraph. The open tag does a hard line break. A fixed
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font style (unless VARIABLE is present) is pushed on the style stack. The
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close tag pops the top of the style stack. It also does a hard line break.
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<BR>Attributes:
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<UL><B>WRAP</B>
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<BR><B>COLS</B>=int [clamped: >= 0]
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<BR><B>TABSTOP</B>=int [clamped: >= 0; clamped value is replaced with default
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value]
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<BR><B>VARIABLE</B></UL>
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</UL>
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<B>NOBR</B>
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<UL>This tag doesn't nest. Instead it just sets or clears a flag in the
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state machine. It has no effect on any other state.</UL>
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<B>CENTER</B>
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<UL>Closes the paragraph. Always does a conditional soft line break. The
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open tag pushes an alignment on the aligment stack. The close tag pops
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the top alignment off.
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<BR>Attributes: none</UL>
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<B>DIV</B>
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<UL>Closes the paragraph. Always does a conditional soft line break. COLS
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defines the number of columns to layout in (like MULTICOL). The open tag
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pushes an alignment on the alignment stack (if COLS > 1 then it pretends
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to be a MULTICOL tag). The close tag pops an aligment from the alignment
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stack.
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<BR>Attributes:
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<UL><B>ALIGN</B>=divalign
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<BR><B>COLS</B>=int [if cols > 1 then DIV acts like a MULTICOL tag else
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DIV is just a container]
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<UL><B>GUTTER</B>= int (clamped: >= 1)
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<BR><B>WIDTH</B>= value-or-pct [pct of right-left margin; clamped >= 1/0
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(strange code)]</UL>
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</UL>
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</UL>
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<B>H1-H6</B>
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<UL>Closes the paragraph. The open tag does a hard line break and pushes
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a style item which enables bold and disables fixed and italic. The close
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tag always pops the top item from the style stack. It also does a hard
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line break. If the <B>ALIGN</B> attribute is present then the open tag
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pushes an alignment on the alignment stack. The close tag will look at
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the top of the alignment stack and if its a header of any kind (H1 through
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H6) then the alignment is popped. In either case the close tag also does
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|
a conditional soft line break (this happens before the hard line break).
|
|
<BR>Attributes:
|
|
<UL><B>ALIGN</B>=divalign</UL>
|
|
</UL>
|
|
A note regarding closing paragraphs: Any time a close paragraph is done
|
|
(for any tag) if the top of the alignment stack has a tag named "P" then
|
|
a conditional soft line break is done and the alignment is popped.
|
|
<H3>
|
|
|
|
<HR ALIGN=LEFT WIDTH="50%"></H3>
|
|
<B>TABLE</B>
|
|
<UL>Close the paragraph.
|
|
<BR>Attributes:
|
|
<UL><B>ALIGN=</B>left|right|center|abscenter
|
|
<BR><B>BORDER</B>=int [clamped: if null then -1, if < 1 then 1 ]
|
|
<BR><B>BORDERCOLOR</B>=string [if not supplied then set to the text color
|
|
]
|
|
<BR><B>VSPACE</B>=int [ clamped: >= 0 ]
|
|
<BR><B>HSPACE</B>=int [ clamped: >= 0 ]
|
|
<BR><B>BGCOLOR</B>=color
|
|
<BR><B>BACKGROUND</B>=url
|
|
<BR><B>WIDTH</B>=value-or-pct [ % of win.width minus margins; clamped:
|
|
>= 0 ]
|
|
<BR><B>HEIGHT</B>=value-or-pct [ % of win.height minus margins; clamped:
|
|
>= 0 ]
|
|
<BR><B>CELLPADDING</B>=int [clamped: >= 0; separate pads take precedence
|
|
]
|
|
<BR><B>TOPPADDING</B>= int [clamped: >= 0 ]
|
|
<BR><B>BOTTOMPADDING</B>= int [clamped: >= 0 ]
|
|
<BR><B>LEFTPADDING</B>= int [clamped: >= 0 ]
|
|
<BR><B>RIGHTPADDING</B>= int [clamped: >= 0 ]
|
|
<BR><B>CELLSPACING</B>= int [clamped: >= 0 ]
|
|
<BR><B>COLS</B>=int [clamped: >= 0]</UL>
|
|
The code supports more attributes in the Table attribute handler than it
|
|
does in the code that gets the attributes from the tag! They are border_top,
|
|
border_left, border_right, border_bottom, border_style (defaults to outset;
|
|
allows for outset/dotted/none/dashed/solid/double/groove/ridge/inset).</UL>
|
|
<B>TR</B>
|
|
<UL>Open TR automatically closes an open table row (and an open table cell
|
|
if one is open). It also automatically closes a CAPTION tag.
|
|
<BR>Attributes:
|
|
<UL><B>BGCOLOR</B>=color
|
|
<BR><B>BACKGROUND</B>=url
|
|
<BR><B>VALIGN</B>=top|bottom|middle|center(==middle)|baseline; default
|
|
is top
|
|
<BR><B>ALIGN</B>=left|right|middle|center(==middle); default is left</UL>
|
|
</UL>
|
|
<B>TH, TD</B>
|
|
<UL>If no table then the tag is ignored (open or close). If no row is currently
|
|
opened or the current row is current done (because of a </TR> tag) then
|
|
a new row is begun. Oddly enough the tag parameters for the row come from
|
|
the TH/TD tag in this case. An open of either of these tags will automatically
|
|
close the previous cell.
|
|
<BR>Attributes:
|
|
<UL><B>COLSPAN</B>=int [clamped: >= 1 && <= 1000 ]
|
|
<BR><B>ROWSPAN</B>=int [clamped: >= 1 && <= 10000 ]
|
|
<BR><B>NOWRAP</B> [boolean: disables wrapping ]
|
|
<BR><B>BGCOLOR</B>=color [default: inherit from the row; if not row then
|
|
table; if not table then inherit from an outer table cell; this works because
|
|
the style is flattened so the outer table cell will have a color]
|
|
<BR><B>BACKGROUND</B>=url [same rules as bgcolor for inheritance; tile
|
|
mode is inherited too and not settable by TH/TD attributes (have to use
|
|
style sheets for that)]
|
|
<BR><B>VALIGN</B>=top|bottom|middle|center(==middle)|baseline; default
|
|
is top
|
|
<BR><B>ALIGN</B>=left|right|middle|center(==middle); default is left
|
|
<BR><B>WIDTH</B>=value-or-pct [ clamped: >= 0 ]
|
|
<BR><B>HEIGHT</B>=value-or-pct [ clamped: >= 0 ]</UL>
|
|
</UL>
|
|
<B>CAPTION</B>
|
|
<UL>An open caption tag will automatically close an open table row (and
|
|
an open cell).
|
|
<BR>Attributes:
|
|
<UL><B>ALIGN</B>=bottom</UL>
|
|
The code sets the vertical alignment to top w/o providing a mechanism for
|
|
the user to set it (there is no VALIGN attribute).</UL>
|
|
<B>MULTICOL</B>
|
|
<UL>The open tag does a hard line break. The close tag checks to see if
|
|
the state machine has an open multicol and if it does then it does a conditional
|
|
soft line break and then continues to break until both margins are cleared
|
|
of floating elements. It recomputes the margins based on the list indenting
|
|
level (?). After the synthetic table is output the close tag does a hard
|
|
line break.
|
|
|
|
<P>This tag will treat the input as source for a table with one row and
|
|
COLS columns. The data is laid out using the width divided by the number
|
|
of columns. After the total height is known, the content is partitioned
|
|
as evenly as possible between the columns in the table.
|
|
<BR>Attributes:
|
|
<UL><B>COLS</B>=int [clamped: values less than 2 cause the tag to be ignored]
|
|
<BR><B>GUTTER</B>=int [clamped: >= 1]
|
|
<BR><B>WIDTH</B>=value-or-pct [pct of right-left margin; clamped: >= 1/0
|
|
(strange code)]</UL>
|
|
</UL>
|
|
|
|
<H3>
|
|
|
|
<HR ALIGN=LEFT WIDTH="50%"></H3>
|
|
<B>BLOCKQUOTE</B>
|
|
<UL>Closes the paragraph. The open tag does a hard line break. A list with
|
|
the empty-bullet style is pushed on the list stack (unless TYPE=cite/jwz
|
|
then a styled list is pushed). The close tag pops any list and does a hard
|
|
line break.
|
|
<BR>Attributes:
|
|
<UL><B>TYPE</B>=cite | jwz</UL>
|
|
</UL>
|
|
<B>UL, OL, MENU, DIR</B>
|
|
<UL>For top-level lists (lists not in lists) a hard break is done on the
|
|
open tag, otherwise a conditional-soft-break is done. Tag always does a
|
|
close paragrah. The close tag does a conditional soft line break when nested;
|
|
when not nested the close tag does a hard line break (even if no list is
|
|
open). The open tag pushes the list on the list stack. The close tag pops
|
|
any list off the list stack.
|
|
<BR>Attributes:
|
|
<UL><B>TYPE</B>= none | disc | circle | round | square | decimal | lower-roman
|
|
| upper-roman | lower-alpha | upper-alpha | A | a | I | i [clamped: if
|
|
none of the above is picked and OL then the bullet type is "number" otherwise
|
|
the bullet type is "basic"]
|
|
<BR><B>START</B>=int [clamped: >= 1]
|
|
<BR><B>COMPACT</B></UL>
|
|
</UL>
|
|
<B>DL</B>
|
|
<UL>Closes the paragraph. For the open tag, if the list is nested then
|
|
a conditional soft line break is done otherwise a hard line break is done.
|
|
The open tag pushes a list on the list stack. The close tag pops any list
|
|
from the list stack. Closing the list acts like other lists closes.
|
|
<BR>Attributes:
|
|
<UL><B>COMPACT</B></UL>
|
|
</UL>
|
|
<B>LI</B>
|
|
<UL>Closes the paragraph. The open tag does a conditional soft line break.
|
|
Close tags are ignored (except for closing the paragraph).
|
|
<BR>Attributes:
|
|
<UL><B>TYPE</B>= A | a | I | i (if the containing list is an <B>OL</B>)
|
|
<BR><B>TYPE</B>= round | circle | square (if the containing list is not
|
|
<B>OL</B> and not <B>DL</B>)
|
|
<BR><B>VALUE</B>=int [clamped: >= 1]</UL>
|
|
The magellan html parser allows the full set of list item styles from the
|
|
OL/DL tag instead of just the limited set that nav4 allows.</UL>
|
|
<B>DD</B>
|
|
<UL>Closes the paragraph. Close tags are ignored (except for closing the
|
|
paragraph). DD outside a DL just advances the X coordinate of layout by
|
|
a small constant. DD inside a DL does a conditional soft line break and
|
|
other margin crud.
|
|
<BR>Attributes: none.</UL>
|
|
<B>DT</B>
|
|
<UL>Closes the paragraph (open or close). Close tags are otherwise ignored.
|
|
Does a conditional soft line break. Moves the X layout coordinate to the
|
|
left margin.
|
|
<BR>Attributes: none</UL>
|
|
|
|
<H3>
|
|
|
|
<HR ALIGN=LEFT WIDTH="50%"></H3>
|
|
<B>A</B>
|
|
<UL>Open anchors push a style on the style stack if the anchor has an <B>HREF</B>.
|
|
Close anchors pop as many styles off the top of the style stack that are
|
|
anchor tags (anchor tags don't nest in other words). In addition, any styles
|
|
on the stack that have the ANCHOR bit set have it cleared and fiddle with
|
|
the foreground and background colors.
|
|
<BR>Attributes:
|
|
<UL><B>NAME</B>=string
|
|
<BR><B>HREF</B>=url
|
|
<UL><B>TARGET</B>=target
|
|
<BR><B>SUPPRESS</B>=true</UL>
|
|
</UL>
|
|
</UL>
|
|
<B>STRIKE, S, TT, CODE, SAMPLE, KBD, B, STRONG, I, EM, VAR, CITE, BLINK,
|
|
BIG, SMALL, U, INLINEINPUT, SPELL</B>
|
|
<UL>The open tag pushes onto the style stack. The close tag always pops
|
|
the top item from the style stack.
|
|
<BR>Attributes: none</UL>
|
|
<B>SUP, SUB</B>
|
|
<UL>The open tag pushes a font size descrease on the style stack. The close
|
|
tag always pops the top of the style stack. The open and close tag impacts
|
|
the baselineThe only difference between SUP and SUB is how they impact
|
|
the baseline. Note that the baseline information is forgotten after a line
|
|
break; therefore a close SUP/SUB on the next line will do strange things.
|
|
<BR>Attributes: none</UL>
|
|
<B>SPAN</B>
|
|
<UL>Ignored by the navigator.
|
|
<BR>Attributes: none</UL>
|
|
<B>FONT</B>
|
|
<UL>The open font tag with no attributes resets the font size to the base
|
|
font size. The open tag always pushes a style stack entry. The close tag
|
|
always pops the top item off the style stack.
|
|
<BR>Attributes:
|
|
<UL><B>SIZE</B>=[+ int | - int | int ] [clamped: >=1 && <=
|
|
7]
|
|
<BR><B>POINT-SIZE=</B>[+ int | - int | int ] [clamped: >= 1 &&
|
|
<= 1600]
|
|
<BR><B>FONT-WEIGHT</B>=[+ int | - int | int ] [clamped: >= 100 &&
|
|
<= 900]
|
|
<BR><B>COLOR</B>=colorspec
|
|
<BR><B>FACE</B>=string</UL>
|
|
</UL>
|
|
A note regarding the style stack: The pop of the stack checks to see if
|
|
the top of the stack is an ANCHOR tag. If it is not an anchor then the
|
|
top item is unconditionally popped. If the top of the style stack is an
|
|
anchor tag then the code searches for either the bottom of the stack or
|
|
the first style stack entry not created by an anchor tag. If the entry
|
|
is followed by another entry then the entry is removed from the stack (an
|
|
out-of-order pop in other words). In this case the anchor style stack entry
|
|
is left untouched.
|
|
<H3>
|
|
|
|
<HR ALIGN=LEFT WIDTH="50%"></H3>
|
|
<B>text, entities</B>
|
|
<UL>These are basic content objects that get fed directly to the output.
|
|
In navigator the text is processed by doing line-breaking (entities have
|
|
been converted to text already by the parser). The line-breaking is controlled
|
|
by the margin settings and the list depth, the floating elements, the style
|
|
attributes (font size, etc.), the preformatted flag, the no-break flag
|
|
and so on.</UL>
|
|
<B>IMG, IMAGE</B>
|
|
<UL>Close tag is ignored.
|
|
<BR>Attributes:
|
|
<UL><B>ISMAP</B>
|
|
<BR><B>USEMAP</B>=url
|
|
<BR><B>ALIGN</B>=alignparam
|
|
<BR><B>SRC</B>=url [ whitespace is stripped ]
|
|
<BR><B>LOWSRC</B>=url
|
|
<BR><B>ALT</B>=string
|
|
<BR><B>WIDTH</B>=value-or-pct (pct of <TT>right-left</TT> width)
|
|
<BR><B>HEIGHT</B>=value-or-pct (pct of window height)
|
|
<BR><B>BORDER</B>=int [clamped: >= 0]
|
|
<BR><B>VSPACE</B>=int [clamped: >= 0]
|
|
<BR><B>HSPACE</B>=int [clamped: >= 0]
|
|
<BR><B>SUPPRESS</B>=true | false (only in blocked image layout???)</UL>
|
|
</UL>
|
|
<B>HR</B>
|
|
<UL>Closes the paragraph. If an open tag then does a conditional soft line
|
|
break. The rule inherits alignment from the parent container unless there
|
|
is no container (then it's centered) or if the tag defines it's own alignment.
|
|
After the object is inserted into the layout stream a soft line break is
|
|
inserted as well.
|
|
<BR>Attributes:
|
|
<UL><B>ALIGN</B>=divalign (sort of; in laytags.c it's divalign; in layhrule.c
|
|
it's left or right only)
|
|
<BR><B>SIZE</B>=int (1 to 100 inclusive)
|
|
<BR><B>WIDTH</B>=val-or-pct (pct of <TT>right-left</TT> width)
|
|
<BR><B>NOSHADE</B></UL>
|
|
</UL>
|
|
<B>BR</B>
|
|
<UL>Does an unconditional soft break. If clear is set then it will also
|
|
soft break until either the left or right or both margins are clear of
|
|
floating elements. Note that<FONT COLOR="#0000FF"> /BR == BR!</FONT>
|
|
<BR>Attributes:
|
|
<UL><B>CLEAR</B>=left | right | all | both</UL>
|
|
</UL>
|
|
<B>WBR</B>
|
|
<UL>Soft word break.
|
|
<BR>Attributes: none</UL>
|
|
<B>EMBED</B>
|
|
<UL>Close tag does nothing. Embed's operate inline just like images (they
|
|
don't close the paragraph).
|
|
<BR>Attributes:
|
|
<UL><B>HIDDEN</B>=no | false | off
|
|
<BR><B>ALIGN</B>=alignparam
|
|
<BR><B>SRC</B>=url
|
|
<BR><B>WIDTH</B>=val-or-pct (pct of <TT>right-left</TT> width)
|
|
<BR><B>HEIGHT</B>=val-of-pct; if val is < 1 (sometimes) the element
|
|
gets HIDDEN automatically
|
|
<BR><B>BORDER</B>=int (unsupported by navigator)
|
|
<BR><B>VSPACE</B>=int [clamped: >= 0]
|
|
<BR><B>HSPACE</B>=int [clamped: >= 0]</UL>
|
|
</UL>
|
|
<B>NOEBMED</B>
|
|
<UL>Used when EMBED's are disabled. It is a container for regular content
|
|
that has no stylistic consequences (no line breaking, no style stack effect,
|
|
etc.).</UL>
|
|
<B>APPLET</B>
|
|
<UL>Applet tags don't nest (there is a notion of current_applet). The open
|
|
tag automatically closes an open applet tag.
|
|
<BR>Attributes:
|
|
<UL><B>ALIGN</B>=alignparam
|
|
<BR><B>CODE</B>=string
|
|
<BR><B>CODEBASE</B>=string
|
|
<BR><B>ARCHIVE</B>=string
|
|
<BR><B>MAYSCRIPT</B>
|
|
<BR><B>NAME</B>=string [clamped: white space is stripped out]
|
|
<BR><B>WIDTH</B>=value-or-pct [pct of right-left width; clamped: >= 1]
|
|
<BR><B>HEIGHT</B>=value-or-pct [pct of window height; clamped >= 1]
|
|
<BR><B>BORDER</B>=int [clamped: >= 0]
|
|
<BR><B>HSPACE</B>=int [clamped: >= 0]
|
|
<BR><B>VSPACE</B>=int [clamped: >= 0]</UL>
|
|
If no width is provided:
|
|
<UL>if a height was provided, use the height. Otherwise, use 90% of the
|
|
window width if percentage widths are allowed, otherwise use a value of
|
|
600.
|
|
<BR> </UL>
|
|
If no height is provided:
|
|
<UL>if a width was provided, use the width. Otherwise, use 50% of the window
|
|
height if percentage widths are allowed, otherwise use a value of 400.</UL>
|
|
If the applet is hidden, then the widht/height get forced to zero.</UL>
|
|
<B>PARAM</B>
|
|
<UL>The param tag is supported when contained by the APPLET tag or the
|
|
OBJECT tag. It has no stylistic consequences. The attribute values from
|
|
the tag are passed to the containing APPLET or OBJECT. Note that <FONT COLOR="#0000FF">/PARAM
|
|
== PARAM</FONT>.
|
|
<BR>Attributes:
|
|
<UL><B>NAME</B>=string [clamped: white space is stripped out]
|
|
<BR><B>VALUE</B>=string [clamped: white space is stripped out]</UL>
|
|
White space being stripped is done as follows: leading and trailing whitespace
|
|
is removed. Any embedded whitespace is left alone except if it's a non-space
|
|
whitespace in which case it is removed.</UL>
|
|
<B>OBJECT</B>
|
|
<UL>The open tag pushes an object onto the object stack. The close tag
|
|
pops from the object stack. I don't understand how the data stuff works.
|
|
<BR>Attributes:
|
|
<UL><B>CLASSID</B>=string (clsid:, java:, javaprogram:, javabean: are the
|
|
supported prefixes; maybe it's a url if no prefix shown?)
|
|
<BR><B>TYPE</B>=string (a mime type)
|
|
<BR><B>DATA</B>=string (data: prefix mentions a url)</UL>
|
|
There are more attributes that depend on the type of object being embedded
|
|
in the page. If the object is a java bean (?) then the applet parameters
|
|
are supported:
|
|
<UL>CLASSID
|
|
<BR>HIDDEN
|
|
<BR>ALIGN
|
|
<BR>CLASSID (instead of CODE)
|
|
<BR>CODEBASE
|
|
<BR>ARCHIVE
|
|
<BR>MAYSCRIPT
|
|
<BR>ID (applets use NAME)
|
|
<BR>WIDTH
|
|
<BR>HEIGHT
|
|
<BR>BORDER
|
|
<BR>HSPACE
|
|
<BR>VSPACE</UL>
|
|
</UL>
|
|
<B>MAP</B>
|
|
<UL>The open tag automatically closes an open map (maps don't nest). There
|
|
is no stylistic consequence of the map nor does it provide any visible
|
|
presentation in the normal layout case (an editor would do something different).
|
|
The map can be declared anywhere in the document.
|
|
<BR>Attributes:
|
|
<UL><B>NAME</B>=string [clamped: white space is stripped out]</UL>
|
|
</UL>
|
|
<B>AREA</B>
|
|
<UL>Does nothing if there is no current map or the tag is a close tag.
|
|
<BR>Attributes:
|
|
<UL><B>SHAPE</B>=default | rect | circle | poly | polygon
|
|
<BR><B>ALT</B>=string [clamped: newlines are stripped]
|
|
<BR><B>COORDS</B>=coord-list
|
|
<BR><B>HREF=</B>url
|
|
<UL><B>TARGET</B>=target (only if HREF is specified)</UL>
|
|
<B>SUPPRESS</B></UL>
|
|
</UL>
|
|
<B>SERVER</B>
|
|
<UL>A container for server-side javascript. Not evaluated by the client
|
|
(parsed and ignored). Note: The navigator parser doesn't expand entities
|
|
in a <B>SERVER </B>tag.</UL>
|
|
<B>SPACER</B>
|
|
<UL>Close tag is ignored. Open tag provides whitespace during layout: <B>TYPE</B>=line/vert/vertical
|
|
causes a conditional soft line break and then adds <B>SIZE </B>to the Y
|
|
layout coordinate. <B>TYPE</B>=word causes a conditional soft word break
|
|
and then adds <B>SIZE </B>to the X layout coordinate. <B>TYPE</B>=block
|
|
causes <FONT COLOR="#DD0000">blockish </FONT>layout stuff to happen.
|
|
<BR>Attributes:
|
|
<UL><B>TYPE</B>=line | vert | vertical | block (default: word)
|
|
<UL><B>ALIGN</B>=alignparam (these 3 params are only for <B>TYPE</B>=block)
|
|
<BR><B>WIDTH</B>=value-or-pct
|
|
<BR><B>HEIGHT</B>=value-or-pct</UL>
|
|
<B>SIZE</B>=int [clampled: >= 0]</UL>
|
|
</UL>
|
|
|
|
<H3>
|
|
|
|
<HR ALIGN=LEFT WIDTH="50%"></H3>
|
|
<B>SCRIPT</B>
|
|
<UL>Note: The navigator parser doesn't expand entities in a SCRIPT tag.
|
|
<BR>Attributes:
|
|
<UL><B>LANGUAGE</B>=LiveScript | Mocha | JavaScript1.1 | JavaScript1.2
|
|
<BR><B>TYPE</B>="text/javascript" | "text/css"
|
|
<BR><B>HREF</B>=url
|
|
<BR><B>ARCHIVE</B>=url
|
|
<BR><B>CODEBASE</B>=url
|
|
<BR><B>ID</B>=string
|
|
<BR><B>SRC</B>=url</UL>
|
|
</UL>
|
|
<B>NOSCRIPT</B>
|
|
<UL>Used when scripting is off or by backrev browsers. It is a container
|
|
that has no stylistic consequences.</UL>
|
|
|
|
<H3>
|
|
|
|
<HR ALIGN=LEFT WIDTH="50%"></H3>
|
|
<B>FORM </B>
|
|
<UL>Attributes:
|
|
<UL><B>ACTION</B>=href
|
|
<BR><B>ENCODING</B>=string
|
|
<BR><B>TARGET</B>=string
|
|
<BR><B>METHOD</B>=get | post</UL>
|
|
</UL>
|
|
<B>ISINDEX </B>
|
|
<UL>This tag is a shortcut for creating a form element with a submit button
|
|
and a single text field. If the PROMPT attribute is not present in the
|
|
tag then the value used is <B>"This is a searchable index. Enter search
|
|
keywords:"</B>.
|
|
|
|
<P>Attributes:
|
|
<UL><B>PROMPT</B>=string
|
|
<BR><B>ACTION</B>=href
|
|
<BR><B>ENCODING</B>=string
|
|
<BR><B>TARGET</B>=string
|
|
<BR><B>METHOD</B>=get | post</UL>
|
|
</UL>
|
|
<B>INPUT </B>
|
|
<UL>Attributes vary according to type:
|
|
<UL><B>TYPE</B>= text | radio | checkbox | hidden | submit | reset | password
|
|
| button | image | file | jot | readonly | object
|
|
<BR><B>NAME</B>= string
|
|
<BR> </UL>
|
|
<B>TYPE</B>=image
|
|
<UL>attributes are from the IMG tag (!)</UL>
|
|
<B>TYPE</B>= text | password | file
|
|
<UL>font style is forced to fixed
|
|
<BR><B>VALUE</B>= string
|
|
<BR><B>SIZE</B>= int (clamped; >= 1)
|
|
<BR><B>MAXLENGTH</B>= int (not clamped!)</UL>
|
|
<B>TYPE</B>= submit | reset | button | hidden | readonly
|
|
<UL><B>VALUE</B>=string; default if no value to the attribute varies according
|
|
to the type:
|
|
<UL><B>submit</B> -> "Submit Query"
|
|
<BR><B>reset</B> -> "Reset"
|
|
<BR>others -> " " (2 spaces)
|
|
<BR>Note also that the value has newlines stripped from it</UL>
|
|
<B>WIDTH</B>=int (clamped >=0 && <= 1000) (only for submit,
|
|
reset or button)
|
|
<BR><B>HEIGHT</B>=int (clamped >=0 && <= 1000) (only for submit,
|
|
reset or button)</UL>
|
|
<B>TYPE</B>=radio | checkbox
|
|
<UL><B>CHECKED</B> (flag - if present then set to true)
|
|
<BR><B>VALUE</B>= string (the default value is "on")</UL>
|
|
</UL>
|
|
<B>SELECT </B>
|
|
<UL>Attributes:
|
|
<UL><B>MULTIPLE</B> (boolean)
|
|
<BR><B>SIZE</B>= int (clamped >= 1)
|
|
<BR><B>NAME=</B> string
|
|
<BR><B>WIDTH</B>= int (clampled >= 0 && <= 1000)
|
|
<BR><B>HEIGHT</B>= int (clamped >= 0 && <= 1000; only examined
|
|
for single entry lists (!multiple || size==1))</UL>
|
|
</UL>
|
|
<B>OPTION </B>
|
|
<UL>Lives inside the SELECT tag (ignored otherwise).
|
|
<BR>Attributes:
|
|
<UL><B>VALUE</B>=string
|
|
<BR><B>SELECTED</B> boolean</UL>
|
|
</UL>
|
|
<B>TEXTAREA </B>
|
|
<UL>Attributes:
|
|
<UL><B>NAME</B>=string
|
|
<BR><B>ROWS</B>=int (clamped; >= 1)
|
|
<BR><B>COLS</B>=int (clamped; >= 1)
|
|
<BR><B>WRAP</B>= off | hard | soft (default is off; any value which is
|
|
not known turns into soft)</UL>
|
|
</UL>
|
|
<B>KEYGEN </B>
|
|
<UL>Attributes:
|
|
<UL><B>NAME</B>=string
|
|
<BR><B>CHALLENGE</B>=string
|
|
<BR><B>PQG</B>=string
|
|
<BR><B>KEYTYPE</B>=string</UL>
|
|
</UL>
|
|
|
|
<H3>
|
|
|
|
<HR ALIGN=LEFT WIDTH="50%"></H3>
|
|
<B>BASEFONT </B>
|
|
<UL>Sets the base font value which +/- size values in FONT tags are relative
|
|
to.
|
|
<BR>Attributes:
|
|
<UL>SIZE=+ int | - int | int (just like FONT)</UL>
|
|
</UL>
|
|
|
|
<H2>
|
|
|
|
<HR WIDTH="100%">Unsupported</H2>
|
|
<B>NSCP_CLOSE, NSCP_OPEN, NSCP_REBLOCK, MQUOTE, CELL, SUBDOC, CERTIFICATE,
|
|
INLINEINPUTTHICK, INLINEINPUTDOTTED, COLORMAP, HYPE, SPELL, NSDT</B>
|
|
<UL>These tags are unsupported because they are used internally by netscape
|
|
and are never seen in real content. If somebody does use them between 4.0
|
|
and magellan, tough beans. We never documented them so they lose.</UL>
|
|
|
|
</BODY>
|
|
</HTML>
|