XP Mail Archive: XP> RE: Specifying the Persistence of Appmu

XP> RE: Specifying the Persistence of Appmuxed Reference Objects

From: BIGELOW,JIM (HP-Boise,ex1) (jim.bigelow@hp.com)
Date: Mon Jan 27 2003 - 17:55:14 EST

  • Next message: BIGELOW,JIM (HP-Boise,ex1): "RE: XP> RE: Specifying the Persistence of Appmuxed Reference Obje cts"

    Hi Dave,

    I wrote on 1/23/03:
    >
    > >I propose that the following paragraph be added to the Section B.2 of
    > >the XHTML-Print spec:
    >
    > >Producers and consumers of Application/Vnd.pwg-multiplexed entities, as
    > >defined in [MIMEMPX], should consider each image as having one and only
    > >one reference. The producer should not make assumptions about the
    > >buffering abilities of the consumer of an
    > >Application/Vnd.pwg-multiplexed entity and include a copy of an image
    > >for each reference to it. Consumers may release the resources
    > >associated with an image when the reference to it is satisfied, and are
    > >free to optimize references to identical images in an implementation
    > >dependent manner.
    >
    You wrote on 1/27/03:
    > I'd be hesitant to just recommend that a producer provide
    > multiple copies of each image without specifying additional
    > detail. RFC2557 (referenced by RFC3391) tells us how to
    > resolve references in a compound document mandates that each
    > part of the multipart message have a unique ContentID and/or
    > unique Content-Location.

    Dave,
    What if the contentID were unique for each image but the content-Location
    identical for each identical image. For example, in the case of a series of
    paragraphs that start with the same image, an information icon, the document
    would look like the following:

    <p class="info"><img src="info_icon.jpg" height="10" width="10">
    Informational message: daba daba do...
    </p>
    <p class="info"><img src="info_icon.jpg" height="10" width="10">
    Windows Haiku:
    Serious error.
    All shortcuts have disappeared.
    Screen. Mind. Both are blank.
    </p>

    Then the multiplexed document would interleave the same image twice, each
    with different contentID's but identical, "info_icon.jpg",
    content-Locations. For example the multiplexed document could look like the
    following:

    Content-Type: application/vnd.pwg-multiplexed;
    type=application/vnd.pwg-xhtml-print+xml

    CHK 1 428 LAST
    Content-Type: application/vnd.pwg-xhtml-print+xml
    Content-Location: infomsg.html
    Content-Disposition: inline

    <?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
    "http://ww.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
    <html xmlns="http://www.w3.org/1999/xhtml">
    <head>
    <title>info</title>
    </head>
    <p class="info"><img src="info_icon.jpg" height="10" width="10">
    Informational message: daba daba do...
    </p>

    CHK 2 1024 LAST
    Content-ID: <49568.45876xxx@foo.com>
    Content-Location: info_icon.jpg
    Content-Type: image/jpeg
    Content-Disposition: attachment

    ... Bytes of info_icon.jpg ...

    CHK 3 253 LAST
    Content-Type: application/vnd.pwg-xhtml-print+xml
    Content-Location: infomsg.html
    Content-Disposition: inline

    <p class="info"><img src="info_icon.jpg" height="10" width="10">
    Windows Haiku:
    Serious error.
    All shortcuts have disappeared.
    Screen. Mind. Both are blank.
    </p>

    CHK 4 1024 LAST
    Content-ID: <49568.46000xxx@foo.com>
    Content-Location: info_icon.jpg
    Content-Type: image/jpeg
    Content-Disposition: attachment
    ... Bytes of info_icon.jpg ...

    CHK 5 113 LAST
    Content-Type: application/vnd.pwg-xhtml-print+xml
    Content-Location: infomsg.html
    Content-Disposition: inline

    <body>
    </body>
    </html>

    CHK 0 0 LAST

    This method would allow the printer to only store the single image since the
    names are the same.

    Based on this approached I suggest the following, amended paragraph be added
    to section B.2:

    Producers and consumers of Application/Vnd.pwg-multiplexed
    entities, as defined in [MIMEMPX], should consider each
    image as having one and only one reference. The producer
    should not make assumptions about the buffering abilities
    of the consumer of an Application/Vnd.pwg-multiplexed
    entity and include a copy of an image for each reference
    to it. Each chunk containing an image should have a unique
    ContentID and a Content-Location whose value is the name
    of the image referenced in the src attribute of the img
    element or the href attribute of the object element.
    Consumers may release the resources associated with
    an image when the reference to it is satisfied, and are
    free to optimize references to identical images in an
    implementation dependent manner.

    Jim Bigelow,
    Editor: XHTML-Print & CSS Print Profile
    IEEE-ISTO, Printer Working Group
    http://www.pwg.org/xhtml-print
    Hewlett-Packard
    208-396-2068
    jim.bigelow@hp.com



    This archive was generated by hypermail 2b29 : Mon Jan 27 2003 - 17:55:22 EST