docbook-apps

  • 1.  Re: [docbook-apps] HTML Column Width Trouble

    Posted 07-09-2009 00:39
    HTML Column Width TroubleI looked into this problem, and it appears that the tablecolumns.extension works fine in HTML, but not in XHTML. And as far as I can tell, the tablecolumns.extension has *never* worked for XHTML output. If someone has experience otherwise, please let me know.

    Background: the basic problem that the tablecolumns.extension tries to address is that, according to the HTML standards, the units for widths of HTML table columns can be only one of three types:

    - a number, which is treated as pixels
    - a % value (of the table width)
    - a relative value such as "2*" (which is not universally supported in browsers).

    So any CALS column widths that are specified in units such as "cm" or "in" must be converted to pixels or they will be misinterpreted. The extension does the math based on some assumed conversion ratio. That is what happens when the file is processed with the HTML stylesheet:




    The problem with XHTML seems to be a namespace problem. The stylesheet forms a temporary nodeset that it hands off to the Java extension functions written by Norm Walsh. When that temporary colgroup is formed in the XHTML stylesheet, it is in the default namespace, which is the XHTML namespace that the stylesheet sets up:
    <xsl:stylesheet xmlns="http://www.w3.org/1999/xhtml" ...

    It appears that the Java extension functions do not handle elements in this namespace (not surprising if they were not written to do so). The result is that it just copies the colgroup back without making any changes, since it does not recognize the elements. In this case, the values of "1in" and "3in" in the CALS table specs are passed through to the XHTML output, where they are interpreted as 1 pixel and 3 pixels, respectively. That forces the columns to be as narrow as possible. The fact that some browsers actually understand "1in" and "3in" I put down to simply being a miracle since none of the HTML standards specify such units.

    I confirmed that the namespace was the problem by stripping the temporary colgroup of its namespace before passing it to the Java extension. Then the extension worked properly and returned a colgroup with widths specified in pixels. That colgroup would then need to be converted back into the XHTML namespace before output.

    The real solution is for Norm or another Java programmer to update the Java source for the tablecolumns.extension function to work with elements in the XHTML namespace as well as the null namespace. If I can't find someone to do that I'll change the table templates to strip the namespace before passing it to the extension.

    Bob Stayton
    Sagehill Enterprises
    bobs@sagehill.net





  • 2.  RE: [docbook-apps] HTML Column Width Trouble

    Posted 07-09-2009 12:44
    Bob,
    Thanks for looking in to this. It may not be "that" big a deal since it
    looks like XHTML is going the way of the Dodo.

    As a work around we just conditionalized the column specs to only work
    for the PDF. Without specified widths the tables look passable in the
    XHTML.
    Cheers,
    Eric



    ________________________________

    From: Bob Stayton [mailto:bobs@sagehill.net]
    Sent: Wednesday, July 08, 2009 8:39 PM
    To: Eric Johnson; docbook-apps
    Subject: Re: [docbook-apps] HTML Column Width Trouble


    I looked into this problem, and it appears that the
    tablecolumns.extension works fine in HTML, but not in XHTML. And as far
    as I can tell, the tablecolumns.extension has *never* worked for XHTML
    output. If someone has experience otherwise, please let me know.

    Background: the basic problem that the tablecolumns.extension tries to
    address is that, according to the HTML standards, the units for widths
    of HTML table columns can be only one of three types:

    - a number, which is treated as pixels
    - a % value (of the table width)
    - a relative value such as "2*" (which is not universally supported in
    browsers).

    So any CALS column widths that are specified in units such as "cm" or
    "in" must be converted to pixels or they will be misinterpreted. The
    extension does the math based on some assumed conversion ratio. That is
    what happens when the file is processed with the HTML stylesheet:




    The problem with XHTML seems to be a namespace problem. The stylesheet
    forms a temporary nodeset that it hands off to the Java
    extension functions written by Norm Walsh. When that temporary colgroup
    is formed in the XHTML stylesheet, it is in the default namespace, which
    is the XHTML namespace that the stylesheet sets up:

    <xsl:stylesheet xmlns="http://www.w3.org/1999/xhtml" ...

    It appears that the Java extension functions do not handle elements in
    this namespace (not surprising if they were not written to do so). The
    result is that it just copies the colgroup back without making any
    changes, since it does not recognize the elements. In this case, the
    values of "1in" and "3in" in the CALS table specs are passed through to
    the XHTML output, where they are interpreted as 1 pixel and 3 pixels,
    respectively. That forces the columns to be as narrow as possible. The
    fact that some browsers actually understand "1in" and "3in" I put down
    to simply being a miracle since none of the HTML standards specify such
    units.

    I confirmed that the namespace was the problem by stripping the
    temporary colgroup of its namespace before passing it to the Java
    extension. Then the extension worked properly and returned a colgroup
    with widths specified in pixels. That colgroup would then need to be
    converted back into the XHTML namespace before output.

    The real solution is for Norm or another Java programmer to update the
    Java source for the tablecolumns.extension function to work with
    elements in the XHTML namespace as well as the null namespace. If I
    can't find someone to do that I'll change the table templates to strip
    the namespace before passing it to the extension.

    Bob Stayton
    Sagehill Enterprises
    bobs@sagehill.net




    Original Message


  • 3.  RE: [docbook-apps] HTML Column Width Trouble

    Posted 07-13-2009 22:08
    |
    Original Message


  • 4.  Re: [docbook-apps] HTML Column Width Trouble

    Posted 07-13-2009 22:15
    1.75.2 is scheduled to release on Monday, and it should include this update.

    On Mon, Jul 13, 2009 at 3:08 PM, Mauritz Jeanson<mj@johanneberg.com> wrote:
    > |  
    Original Message


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