Re: svn commit: r911476 - /cayenne/main/trunk/framework/cayenne-tools/src/main/resources/templates/v1_2/client-datamap-superclass.vm

From: Mike Kienenberger (mkienen..mail.com)
Date: Thu Feb 18 2010 - 22:00:47 EST

  • Next message: Andrey Razumovsky: "Re: svn commit: r911476 - /cayenne/main/trunk/framework/cayenne-tools/src/main/resources/templates/v1_2/client-datamap-superclass.vm"

    Yes, we need a cgen version, although it will probably change very infrequently.

    No, it is not the same version as the templates. Even though Andrey
    had to change the templates, we do not have to change cgen itself.

    It's been a long time since I upgraded cgen from version 1.1 to 1.2,
    but basically the version determines what cgen puts into the velocity
    context.

    For cgen 1.1, I think the only thing we made available to the template
    was a java class instance called "classGen".

    For 1.2, the exposed data model was completely changed. Here's some
    of the variables exposed to the template (from the 1.2 standard
    template comments):

    ## objEntity - the ObjEntity class: See
    org.objectstyle.cayenne.map.ObjectEntity
    ## stringUtils - class for string "helper" functions: See
    org.objectstyle.cayenne.gen.StringUtils
    ## entityUtils - class for entity "helper" functions: See
    org.objectstyle.cayenne.gen.EntityUtils
    ## importUtils - class for import statement management: See
    org.objectstyle.cayenne.gen.ImportUtils

    So a template written against 1.1 cannot work under 1.2, nor can a
    template under 1.2 work under cgen 1.1.

    As for the confusion, if it hasn't confused anyone in several years,
    it's unlikely to start confusing them just because we're now on 3.1 :)

    However, a cgen 1.1 template can work with Velocity 1.3 or 1.6 or whatever.
    A cgen 1.2 template can likewise work with different versions of velocity.

    So someone who has a ton of velocity templates (like myself) can be
    assured that they don't need to be rewritten under Cayenne 3.1. Yes,
    we might have to tweak a couple of things here and there if we upgrade
    to velocity 1.6, but anyone who's maintaining their own velocity
    templates has pretty much been aware (for a few years now) that we
    were going to have to handle this at one point or another.

    And quite honestly, I doubt that there's really anything stopping
    someone from reverting back to Velocity 1.3 if they so desire.
    There's nothing architecturally different that I'm aware of. I
    haven't looked at velocity changes in a couple of years, but I'm
    pretty sure that velocity 1.6 is at least a couple of years old at
    this point.

    On Thu, Feb 18, 2010 at 7:42 PM, Aristedes Maniatis <ar..aniatis.org> wrote:
    > On 19/02/10 9:44 AM, Mike Kienenberger wrote:
    >>
    >> v1.2 is the cgen version.  It's fine and doesn't need to be changed.
    >> We would only change that version if we did further work on the cgen
    >> engine.
    >
    > End users will probably confuse 1.2 with the Cayenne 1.2 release version
    > number.
    >
    > * why do we have a version at all? Surely the templates which ship with
    > Cayenne 3.1 are the templates which work with 3.1. Should the user be given
    > the choice to use version 1.1 templates or 1.2 templates, when only the 1.2
    > templates will work.
    >
    > * Andrey just introduced a change which makes the templates non-backward
    > compatible. So if we keep the versioning, we should move to 1.3 to identify
    > to the user that things have changed.
    >
    >
    >
    > Ari
    >
    > --
    > -------------------------->
    > Aristedes Maniatis
    > GPG fingerprint CBFB 84B4 738D 4E87 5E5C  5EFA EF6A 7D2E 3E49 102A
    >



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