IPP Mail Archive: IPP> Sketch of an idea: Define a Resource

IPP Mail Archive: IPP> Sketch of an idea: Define a Resource

IPP> Sketch of an idea: Define a Resource container object for Print D river Extension and other sub-types

From: Hastings, Tom N (hastings@cp10.es.xerox.com)
Date: Tue May 09 2000 - 14:16:38 EDT

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    We have discussed several times on the IPP telecons about adding a new
    Resource object. This mail note is a sketch of the idea to see if there is
    support for developing an IPP spec along these lines. The reason to being
    this idea up now is because of the discussion of the Print Driver Extension.
    The Resource object approach would allow a way to install print drivers on
    the Printer and to Get Print Drivers from the Printer to install on a
    client. It would allow a Printer to have more than one print driver, say
    one for each of a number of different OS platforms and/or PDLs.

    Should the Resource object be an agenda topic for the New York City IPP WG
    Meeting, 5/17-18?

    Here is the sketch of the Resource object idea and its operations:

    The Resource object is a generic container object for a number of sub-typed
    objects. The Resource object would have a number of operations defined.
    Each operation would include an operation attribute that identifies the
    object sub-type in question. Then implementers could define new sub-types
    easily without having to invent new operations.

    There are some attributes common to all sub-types, such as the
    "resource-name", "resource-sub-type", "resource-owner",
    "resource-creation-date-time", etc., and a lot that are specific to a
    particular sub-type. Some sub-types will also have opaque data associated
    with each object instance (such as fonts, forms, images, and print drivers),
    and others will only have attributes (such as media).

    The initial list of sub-types include:

    media - Just attributes which define the media characteristics. So the
    client can query the media library and the administrator can add new media
    and define their characteristics
    fonts - attributes and the PDL data
    forms - attributes and the PDL data
    logos - attributes and the PDL data
    images - attributes and the PDL data. high resolution images can be put
    into a shared image library and called out from a number of documents
    print drivers - attributes and the opaque data is the executable code

    The operations would include:

    Create-Resource - the client specifies the resource type and a user-friendly
    name for it that is used in all subsequent operations, including Job
    Submission operations (Print-Job, Create-Job, Send-Document). A lease time
    is also requested (just like our Subscription objects) and the Printer
    returns the lease time granted (which may be infinite meaning no need to
    renew or finite, meaning that the client must renew the lease, else the
    resource will be deleted).

    Delete-Resource - delete the named resource of the indicated sub-type

    Renew-Resource - renews the lease, in case it wasn't infinite

    Get-Resource-Attributes - returns the requested (or all) attributes of a
    specified resource type and instance.

    Get-Resources - returns the requested (or all) attributes of a specified
    resource type that matches the supplied filter criteria consisting of any of
    the resource attributes. Here the filtering is more complex than we have
    for Get-Jobs or Get-Subscriptions operations, since the client could filter
    on any of the resource attribute values. For example, a client could
    request all of the media that has a "media-size" equal to particular pair of
    x and y dimensions and get back the other resource attributes of any matched
    media instances.

    Get-Resource-Data - returns the opaque data for those resources for which
    the data is not copyrighted, etc.

    These operations are very similar to the Subscription object operations that
    the IPP WG has nearly approved for notification. The only differences are:
    Subscription Ids are assigned by the Printer as numbers, while resource
    object instances have user friendly names assigned by the creator. Both
    have leases, but Subscription leases are expected to be much shorter
    (minutes, hours) and handled by the software, not the user, while Resource
    objects leases are much longer (days, weeks, months), though both can be
    infinite depending on SA policy, and the user or administrator explicitly
    creates the Resources. Also Resources are known to users and administrators
    and are managed by them. Also Subscriptions don't have any complex filtering
    in the query requests.

    [We don't want to merge Subscriptions into Resources, just illustrate their

    It will also allow the administrator to set up policy on who can create
    which kinds of resources and for how long.



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