Re: DOCBOOK-APPS: Re: DOCBOOK: ISO Entities

[Bob Stayton <bobs@caldera.com>]

> From: Norman Walsh <ndw@nwalsh.com>
> 
> [ I'm moving this thread to docbook-apps ]
> 
> / "Kaiser Christian (SV SC RS T33)" <Christian.1.Kaiser@at.siemens.de> was heard to say:
> | >/ "Kaiser Christian (SV SC RS T33)" <Christian.1.Kaiser@at.siemens.de> was
> | heard to say:
> | >| how can implement symbols such as....
> | >| 
> | >|       "DOES NOT CONTAIN AS NORMAL SUBGROUP"  <!-- iso-amsn seems to be
> | >| responsible -->
> | >| 
> | >| I know the Identifier to use is .... 
> | >| 
> | >|       PUBLIC "ISO 8879:1986//ENTITIES Added Math Symbols: Negated
> | >| Relations//EN//XML"
> | >| 
> | >| What do I have to do with it?
> [...]
> | I'm using XML DocBook 5.0 with Xalan (+ FOP) to create HTML (and PDF)
> | output.
> | I'm sorry, I think chose the wrong word by using "implementation".
> | All I want to see as a result is a mathematical symbol within my output.
> 
> No, that's what I thought you meant. Ok, here's the scoop...
> 
> If you look at the intermediate result, after Xalan but before FOP,
> you'll see that the HTML or FO file contains "&#x22EB;" (or its decimal
> equivalent, or its UTF-8 equivalent) everywhere that you've used
> &nrtri;.
> 
> So far, so good. That's the Unicode code point for the character you want.
> 
> The backend (FOP at least) should "do the right thing". But it
> probably doesn't. Unfortunately, I think the fix has to be performed
> at that level.
> 
> For HTML, the problem is more difficult because many browsers aren't
> expecting Unicode. If you need interoperability, you'll probably have
> to switch to a graphic (and this might work for FOP as well).

One minor clarification.  The major browsers will accept HTML
with the most common encoding of Unicode, utf-8, if you include in
your HTML:

<meta content="text/html; charset=UTF-8" http-equiv="Content-Type">

You can get that output through a small customization
of the <xsl:output> element in the XSL stylesheet.

But, dashing your hopes, this doesn't solve the basic
problem, which is that most operating systems don't provide
complete Unicode glyph collections for such browsers to
display.  So you are left with Norm's solution, a graphic.
Unfortunately, a graphic won't scale if someone enlarges
their font (as I found once when doing a presentation
using HTML), but at least the meaning will be there.

Maybe someday the 'uni-' in Unicode will mean
universally implemented.

bobs
Bob Stayton                                 400 Encinal Street
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                                            email: bobs@caldera.com