Tuesday 11 April 2006

Community Mapbuilder State Of Play - April 2006


This document summarises the state of the Mapbuilder project and it's relationship with projects around it, identify upcoming features and opportunities, and suggest where to focus future effort and funding to maximise Mapbuilder's potential.

There has been a significant increase in developers downloading and extending Mapbuilder code. To maximise Mapbuilder's potential for developers, users and sponsors, the focus of core developers should move from development toward supporting and mentoring new developers. Similarly, sponsors should dedicate part of their funds to Mapbuilder mentors. Sponsor one mentor and you get five developers for free.

1. What is Mapbuilder?

Mapbuilder is a modern, web based geographic mapping client. It's modular design has made it easy for developers to build an every increasing library of widgets and tools to plug into Mapbuilder. In particular, Mapbuilder stands out from other Webmapping clients because it allows users to draw vector features on a map then load the feature into a Transactional Web Feature Service.

Mapbuilder is built upon OGC standards and hence is interoperable with many other Geospatial applications.

Mapbuilder has grown a strong, diverse and active developer community and as Mapbuilder reaches it's 1.0 release it is being recognised as a quality product. Mapbuilder is bundled with Geoserver, an Open Source Web Map Service (WMS) and Transactional Web Feature Service (WFS), and Mapbuilder was selected as one of the founding projects for OSGeo, the Open Source Geospatial Foundation.

2. What big ticket items are in the pipeline?

2.1. Geographic wiki

Web Mapping to date has focused on Publishing mapping data. Feature entry functionality is being added to Mapbuilder which will allow users to create, edit, then upload geographic features.

2.2. Integrated Suite of Open Source Mapping products

There is a full range of high quality open source geospatial software which interacts which each other using Open Standards - however the installation and configuration of these products is still disjointed. Over the next few years, these projects are likely to integrate more closely providing easy to install and configure solutions.

In particular, Mapbuilder is currently bundled with Geoserver, an open source WFS/WMS, and there is an opportunity for Mapbuilder to be bundled with Udig to provide a heavy/light client solution.

2.3. Roll your own Webmapping Client

Imagine a web page which looked like a drawing program like Visio. On the left is a list of widgets which can be dragged onto a Pane on the right. After the user has selected and placed their widgets, the use can assign attributes like Map Layers.

http://www.netvibes.com/ uses a similar concept which made it very popular.

2.4. AJAX drawing tool

Mapbuilder has developed effective drawing functionality which would be useful for a wide range of applications. This should be factored out into a separate library so that it can be used by other applications.

2.5. Lots of extra widgets and features

Google and Yahoo Map layers, fast vector rendering of features (eg using SVG), tiled maps, and much more.

3. Managing growth

Figure 1. 

Over the last year Mapbuilder has had a steady increase in interest from developers and users. Traffic on our email lists has increased by a factor of five over the last year. Increasingly we are seeing questions from paid portal developers who extend Mapbuilder, then move on. Since most core developers work on Mapbuilder in their spare time the core developers are having problems supporting users and incorporating the user's code.

Almost all Mapbuilder queries are from developers, which is an indication that Mapbuilder documentation and installation procedures are too difficult for average internet users.

Mapbuilder's user documentation is still poor which is part of the reason for the large number of user queries. Improving documentation will empower users to answer their own queries, and will increase Mapbuilder's user base because more people will be able to use it.

4. Funding

Mapbuilder has grown to privileged position where we are starting to have access to more developers than the core team can support. To accept developer contributions, we need to provide guidance, answer technical questions, review code and incorporate additions into the code base. Part of the support can be provided by writing good supporting documentation.

If you are considering using or extending Mapbuilder, sponsoring a Mapbuilder mentor will probably make sense for you. Sponsor one mentor and get five developers for free. For a company who wants to extend Mapbuilder, I suggest you hire a developer to implement your desired features and a mentor for 1/5 of your developer's time. This will ensure your code is reviewed and incorporated into the Mapbuilder codebase and available in future Mapbuilder releases. If your desired functionality is popular, it may be more economical to just support a Mapbuilder mentor which in turn will empower other Mapbuilder developers to implement features on your behalf.

5. Integrating with projects around us

The commercial world regularly tries to out do and compete against similar projects, but in Open Source we can do much better by embracing and working together.

5.1. Web mapping clients

There are a number of web mapping clients doing similar things to Mapbuilder or with features that Mapbuilder would like to copy. The projects all contain talented software developers and we would all do better if we could share our workload and focus on one great product instead of lots of good products.

Unfortunately it is difficult to merge two code bases together and no one wants to give up a project they have spent lots of time on to go and work on someone else's code.

So what I propose is that we work toward a long term goal of merging projects. We start by gradually factoring out common libraries that we work on together, and whenever we make future design decisions, we run the idea past other projects and see if we reuse code or interfaces which will ease merging some time in the future. webmap-discuss@lists.osgeo.org has been set up to facilitate this.

5.2. OpenStreetMap and other Geowikis

http://www.openstreetmap.org/ is a project which allows users to upload tracks from GPS devices (like handheld computers or phones) into a geographic database, then provides a java applet to edit those same features. They have addresses some of the hard issues, like version control on features at the expense of breaking away from Open Standards. And they are already collecting data from users.

This is a project that would be great to work with. They have a great vision, and some good ideas. We could add value to them by providing our AJAX based web mapping client - they have a Java applet. Java applets are a stumbling block for many non-technical users because it requires them to download and install extra software into their browser. We could help them migrate toward a standards based solution, which would enable them to tap into other powerful mapping applications (like UDig).

There has been talk on Wikipedia about setting up a geographic wiki. Mapbuilder could be the tool used for a Wikipedia for geographic maps.

5.3. Basemap providers

There has been an explosion of quality free basemaps on the internet from companies like Google, Yahoo, and MSN. These companies also provide viewers which could be seen as competitors to Mapbuilder. These companies could be seen as potential sponsors for the Mapbuilder project as their code value is in their maps, not the mapping client.

5.4. AJAX Engines

Mapbuilder has built it's own AJAX software - (software which handles asynchronous loading, events, javascript inheritance etc). It is powerful, and it works, however some of the code is not very elegant, and because we were experimenting as we wrote it, we have instances where concepts like inheritance are implemented in two different ways. This makes the code harder to understand and more prone to bugs.

Since we wrote Mapbuilder, there have been a number of quality AJAX Engines written. It would be wise of Mapbuilder to replace our engine with one of the dedicated engines. The advantages would be: more reliable code, maintenance would be spread across a larger user base and we can tap into the expertise of the developers on these projects.

5.5. Geoserver

Geoserver is a Java based Transactional Web Feature Service (WFS-T) and Web Map Service. Mapbuilder is currently bundled with Geoserver which probably explains why a number of our quality developers have been attracted to Mapbuilder.

We need to ensure that Mapbuilder continues to be bundled with Geoserver and ensure that Geoserver ships with the latest version of Mapbuilder.

5.6. UDig

UDig is a powerful GIS desktop application. It would be very useful for users to bundle Mapbuilder with UDig to provide a light/heavy client option.

5.7. Open Web Services Testbed (OWS4)

The OWS4 testbed sponsored by the Open Geospatial Consortium would be an excellent opportunity to show case Mapbuilder and UDig integration.

6. Areas for improvement

6.1. Documentation

Mapbuilder's documentation needs to catch up to the quality of the code. By improving our documentation, we won't need to keep answering the same questions on email lists and will increase our user base. Increased users, means increased developers and sponsorship and a healthier project.

The catch is that the people who know the most about the code (the developers) don't need the documentation and sponsors often want to pay for a feature and move on. Good documentation is a long term investment in a project.

6.2. Testing

It is a credit to the Mapbuilder team that Mapbuilder is so stable considering that it targets the flaky browser platforms.

To date Mapbuilder has only just started looking at automated testing, however it has not been rolled out across the project. Automated testing will help ensure Mapbuilder remains stable and give us confidence to take on more developers.

6.3. Core code

Mapbuilder's code has gone through many improvements as we have pioneered and experimented with AJAX techniques. As such there are areas of code which still contain old hacks and plenty of areas where we could simplify code. This would reduce download size, reduce complexity and improve maintainability.

We should do a systematic code review and clean up and improve our existing core code, and replace some of our code with standard AJAX libraries.

6.4. Managing new developers and funding

We have become overwhelmed with new developers and their questions. This is a good thing, but we do need to change the way we do things. In particular, the core team needs to focus more on Mentoring new developers. Ideally, sponsors should consider sponsoring a Mapbuilder mentor. Sponsor one mentor, get five developers for free.

6.5. Visibility

To build the project's profile, we should present Mapbuilder at various conferences.

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