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List:       xmlbeans-dev
Subject:    Fwd: Proposal for xmlbeanscxx
From:       Cliff Schmidt <cliffschmidt () gmail ! com>
Date:       2005-05-20 17:07:56
Message-ID: c5e632550505201007573809a1 () mail ! gmail ! com
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Hey Axis Folks!

I'm forwarding this proposal for a C++ version of XMLBeans, which is
now being discussed on the xmlbeans dev list.  If any of you think
this could be useful to your community, please let us know.

Thanks,
Cliff

---------- Forwarded message ----------
From: Heidi Buelow 
Date: May 15, 2005 11:11 AM
Subject: Proposal for xmlbeanscxx
To: "dev at xmlbeans . apache . org" 

This is a proposal for an xmlbeans subproject which should be discussed here
and voted on at the xmlbeans PMC before going to the incubator for a vote.

Proposal to create a C++ version of the Apache XMLBeans project

Submission date: 15 May 2005, Tim Triemstra, Heidi Buelow (TimT @ RogueWave
dot-com, Buelow @ RogueWave dot-com)

(0) rationale

Apache currently maintains the XMLBeans/Java project, a tool that uses XML
Schema as a basis for generating Java classes used to easily access XML
instance data. The goal of the XMLBeans/C++ project is to provide a very
similar user experience for C++ developers as that provided by the
XMLBeans/Java version. This includes generating strongly-typed C++ classes
for the XML binding as well as providing low-level C++ APIs enabling access
to the raw, underlying XML content. Where possible, the XMLBeans/C++ project
will provide a nearly identical API and parallel architecture to that
provided by the Java counterpart, and will closely mimic both features and
schedule.

Rogue Wave Software will help jump start this project by contributing the
existing XML to C++ binding code distributed as part of the LEIF product to
the Apache community. This product has been in production for over two
years, and will provide a solid foundation for a C++ version of XMLBeans.

(0.1) criteria

Meritocracy: The C++ version of the project should adhere to the same open,
merit-based community standards as other Apache projects.

Contributions and Core Developers: Code being contributed is actually a
subset of the LEIF product. Currently, work is underway to remove any
proprietary dependencies from within the code. A "cleaned" version that is
ready for contribution will be made available to the community around the
middle of May 2005. This initial contribution will be fully functioning, but
missing a few key features of the Java version of XMLBeans.

The community should be able to immediately jump in and begin work, along
side dedicated Rogue Wave personnel, to turn the initial contribution into a
feature-compatible version of XMLBeans for C++.

Community: The community around the Java version of XMLBeans is already
vibrant and growing. There is every reason to believe many of those within
the existing community have experience and/or general interest in a
successful, compatible C++ implementation of the toolset. This should ensure
an immediately active and vocal community, even if the primary interest is
in ensuring a similar experience between versions. There is already a large
group of developers "in the wild" using the original XML to C++ binding tool
that is serving as the original contribution for this project. These users
will be migrating to the XMLBeans/C++ code over time and have already
indicated a keen interest in tracking, and even participating in the
Apache-led project.

Apache Alignment: The XML binding tool from which the XMLBeans/C++ port will
morph does not include a full XML parser, but instead uses a small, focused
parser designed expressly for tight C++ to XML binding support. The general
purpose XML instance data APIs within XMLBeans will require additional code
and may be a good fit for the Xerces parser to enable some required
features.

Additionally, at least one member of an existing Apache project has
expressed interest in a project like XMLBeans/C++ to aid in his current
work. Higher-level projects such as Axis for C++ seem to be natural
beneficiaries of this work.

(0.2) known risks

Orphaned Products: One of the first questions when a commercial entity
offers code to the public is "will this code be abandoned?" To be clear,
Rogue Wave decided to initiate this process due to its own significant
interest in the XMLBeans feature set already present in Java, and its need
for similar features in C++. We have significant product goals moving
forward around XML for which the XMLBeans model fits perfectly. Rather than
simply copy the design and keep the project closed, we felt that the
downstream products would reap significant benefits from opening the XML
layer to the community. Keeping the C++ version in sync with the Java
version, even if it were to not be accepted as an Apache project, can only
help its overall adoption.

Additionally, a diverse committer base is a strong goal for this project.
Numerous users of the contributed XML to C++ binding tool have indicated
interest in participating, many of whom have critical projects dependant on
this work and resources available to continue to ensure the viability of the
project well into the future.

Inexperience with Open Source: Like many companies entering this arena, we
have limited experience working on open source projects. Our primary goal is
to foster an active community around XMLBeans/C++ so advice will be taken to
heart, and significant resources will be dedicated to the project to get it
off the ground. However, we hope that our experience working in open
standards groups will aid in the transition to the open source community.

Initial Reliance on Salaried Workers: Due to the rapid process of
transitioning to work on the open source XMLBeans/C++ project, only a few of
the listed contributors will be outside the commercial realm. We expect this
list of external volunteers to grow significantly after the initial public
code drop.

Licensing, Patents, Miscellaneous Legal: We are conducting a legal review of
the code and existing contracts. This review should be done shortly and any
code contributed will be licensed under the latest ASF terms.

Commercial Interest: XMLBeans/C++ will be maintained as an open source
Apache project, with all relevant enhancements contributed to the community.
Additionally, there is every intention to use XMLBeans/C++ within future
commercial products, thereby resulting in even greater testing and user
exposure. It is expected that other companies may well wish to use the
project's code within their own commercial endeavors, which of course would
be fine.

(1) scope of the subproject

The XMLBeans/C++ subproject will conform to the identical scope as that laid
out for the partner Java project. Special care will be taken to implement
features and add conveniences that would be expected by a C++ developer.

For clarity, the goals of the XMLBeans/C++ project are:

Generation of plain C++ classes to model XML Schema Validation of C++
objects against the source XML Schema Access to partial document instance
data (fragments) Efficient "parse as necessary" access that forgives extra
data Access to the full XML infoset



(2) identify the initial source for subproject code

Some background information may be found on the LEIF product and the
associated Data Tier.

LEIF product page (http://www.roguewave.com/products/leif)

The C++/XML binding contribution code can be found at the following link:

xmlBeans open source information
(http://www.roguewave.com/opensource/XMLbeans.cfm)

(3) identify the ASF resources to be created

(3.1) mailing list(s)

xmlbeanscxx-dev
xmlbeanscxx-user
xmlbeanscxx-commits

(3.2) SVN repositories

xml-xmlbeanscxx

(3.3) Bugzilla

xml xmlbeanscxx

(4.0) identify the initial set of committers

This is a preliminary list that will be updated with volunteer members.

Tim Triemstra (TimT @ RogueWave dot-com)
John Hinke (Hinke @ RogueWave dot-com)
Heidi Buelow (Buelow @ RogueWave dot-com)
Allen Brookes (ABrookes @ RogueWave dot-com)
David Haney (David.Haney @ RogueWave dot-com)
Michael Yoder (Michael.Yoder @ RogueWave dot-com)

(5) identify apache sponsoring individual

Cliff Schmidt, of the XMLBeans/Java project, has volunteered to sponsor this
project.

Cliff Schmidt (CliffS @ Apache dot-org)

(6) open issues for discussion

The original code contribution has a lot of proven code for creating a
binding between XML Schema and C++ classes. However, the contribution will
require a significant overhaul, and even complete re-writes in some areas,
in order to reach compatibility with the XMLBeans/Java version. Detailed
differences will be discussed openly within the community so that an
appropriate plan for each area can be reached. This proposal is not the best
place to lay out all the technical details, however you will find below a
preliminary list of issues, priorities, and estimated timelines.

API discrepencies between contributed code and XMLBeans 2.0 The contributed
code includes a very similar type-binding API in C++ to that provided in
XMLBeans for Java. However, the XMLBeans cursor access to the underlying
infoset has no equivilant in the contributed code and will require extensive
work to the underlying object model to support.

Addressing this deficiency is considered the highest priority task facing
the C++ project.

Several options are available including porting the XMLBeans object model
completely over to C++ or looking for ways to augment the contributed code.
Most likely a near-complete rewrite of this section will be the best
approach.

Rough estimates for a working implementation of the cursor feature are
between three and five months Code generator

The contributed C++ code is based on a proprietary code generator, although
it too is written in Java (not C++). The long-term plan is to consolidate
both C++ and Java projects under the same code generator, most likely the
one already included in the Java version of the XMLBeans.

This is not considered a priority-1 task at this point, more of a long term
goal and convenience. If it saves time in other priority tasks it will be
looked at closely, however.

Timeline for this transition is 5-7 months, but may be very much sooner
depending on available resources.

Platform support
Unlike Java, the C++ port will have significant issues around platform and
compiler support. In order to help with this the project will be using the
C++ standard library, and may in fact benefit greatly from the proposed
Apache C++ StdLib (STDCXX). Initially the native StdLib will be used.

Good platform support will be very important so even the early builds should
be done on Windows and Linux, and preferably at least one Unix variety. Long
term the matrix should be very large.

The initial contribution is working on Linux but it is really just a preview
look at code, not a true product build. Windows and Linux support should
accompany the initial beta release, with Solaris, HP-UX, AIX, and other
Linux distros following within three months.

Estimated timeline (very rough)
Initial submission of proposal and example code: 12 May 2005 Apache
structure in place and code building: 1 July 2005 Re-write of internal
object model building: 1 September 2005 XMLBeans/Java 2.0 feature equivilant
beta: 1 December 2005

This timeline is based on a very preliminary discovery of issues and is
based on limited resource information. There is little chance for this
schedule to be elongated by very much time as there are already a few
dedicated resources assigned to the project, but there is also little known
about how much a concerted community effort could speed things up. In
general the feeling is that a greater community involvement will greatly
improve the test suite, identified bugs, and platform support - not
necessarily the initial speed of feature development.



--------------------
Heidi Buelow
Rogue Wave, a division of Quovadx

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