Fujisawa-san,
Thank you for pointing out this very important requirement of XHTML
languages. I have created a list of all the attributes in XHTML-Print and
noted which are not meaningful, that is, result in a visible change to the
page :
1. when printing a static version of the XHTML-Print document,
2. because of restrictions of image types to jpeg,
3. because only css style sheets are supported, not java style sheets, 4.
because the characters set of XHTML-Print documents is restricted to tuff-8,
and 5. because they are part of functionality that is considered too complex
for low-cost printers.
The last point is important to us, since we hope that every printer could
proved support for XHTML-print to at least the minimum degree of print
quality. The minimum level of print quality is simply printing the
document's text without images.
The attached file lists the attributes with annotations. This file can also
be found at:\
http://www.pwg.org/xhtml-print/HTML-Version/attribute_support.htm
Please note that while the attributes have no meaning in the context of
printing, that is, the printer doesn't have to support them, a printer must
still read and ignore the attribute rather than flushing the document as if
an error had been encountered.
However, after considering attributes, such as title or method, that are
meaningless in the context of printing, there are still several attributes
that are not support for other reasons:
- the value of the type attribute is restricted to "text/css" since
printers are not required to implement a java virtual machine, so java style
sheets are not supported.
- most of the attributes of the object element should be ignored since
printers are not required to try to print the output of java applets.
- support for align and valgin is simplified to reduce buffering and memory
requirements of low-cost printers.
- support for the declare attribute of the object element is not required
due to the large amount of parsing memory needed to hold the entire image as
an attribute value. This would be prohibitive for a low-cost printer
- support for hreflang and charset are not required since the document is
restricted to utf-8 to make things easier for low-cost printers.
- support for xml:lang is not required because of processing restrictions on
low-cost printers.
Please help me understand what we should and should not require of low-cost
printers and if this means that XHTML-Print cannot be in the family of XHTML
languages.
Jim Bigelow
Hewlett-Packard
206-444-0437
jim_bigelow@hp.com
-----Original Message-----
From: Jun Fujisawa [mailto:fujisawa.jun@canon.co.jp]
Sent: Saturday, November 16, 2002 8:51 AM
To: PWG XHTML-Print
Subject: XP> XHTML Host Language conformance
In Section 1.3.6. Attributes, XHTML-Print is described to be a member of the
family of XHTML language. The following description in Section 1.3.6,
however, suggest that XHTML-Print is not a conforming XHTML Host Language.
"These attributes are treated as discretionary in that a conforming printer
is not required to support them, but should a printer wish to provide that
support there are requirements stated for consistency in the implementation
of extensions."
Modularization of XHTML specification request that XHTML Host Language must
meet the following criteria:
"For each of the W3C-defined modules that are included, all of the elements,
attributes, types of attributes (including any required enumerated value
lists), and any required minimal content models must be included (and
optionally extended) in the document type's content model. When content
models are extended, all of the elements and attributes (along with their
types or any required enumerated value lists) required in the original
content model must continue to be required."
<http://www.w3.org/TR/xhtml-modularization/conformance.html#s_conform_docume
nt_type>
I would like to propose that XHTML-Print conforming printer do require the
support of all attributes.
-- Jun Fujisawa <mailto:fujisawa.jun@canon.co.jp>
This archive was generated by hypermail 2b29 : Mon Nov 18 2002 - 19:28:12 EST