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 --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
