Module Development - Advice Needed

["Van Ulden, Joost (NRCan/RNCan)" <jo...@canada.ca>]

Hi all,

I approached a couple of folks at ApacheCon in Vancouver about some work that I am involved with that would benefit from an httpd module. I am sending this message to the list to provide more information, and to seek advice on how we should proceed.

We are developing a format we call "Map Markup Language", or MapML. The objective of this format is to describe Web map semantics - that is scale / zoom, projection, extent, features, styles, licenses, legends in the context of a hypermedia media type that can be manipulated / interacted with through the uniform interface alone.  We would like to eventually register the format as text/mapml.

The niche for the format is best described as "HTML, but for maps".  The draft, and evolving, specification for the format can be found here: http://maps4html.github.io/MapML/spec/, which is one of a group of repos belonging to the W3C Maps for HTML Community Group: https://github.com/Maps4HTML.

We want to develop an httpd module, "mod_mapml" which will allow the admin to configure MapML responses over a map tile cache, using one or more URI templates as configuration parameters.  A Java servlet prototype for this functionality is available: https://github.com/Maps4HTML/MapMLServer.  (For the servlet, the parameters are passed via web.xml).

Examples of MapML responses can be elicited from a running instances of that servlet here, for example:
http://geogratis.gc.ca/mapml/osm/?xmin=9720501&ymin=12017514&xmax=9721201&ymax=12017914&zoom=17&projection=OSMTILE
or
http://geogratis.gc.ca/mapml/fdr_current/?xmin=2312&ymin=2582&xmax=2952&ymax=3062&zoom=2&projection=CBMTILE

We would like some advice on how to proceed with the development of a module. For instance should we pursue this as a third-party module? Can we tap into the community for development assistance if we don't have the required skills in-house? Any advice would be appreciated.

Regards,
________________________________

Joost van Ulden

Project Advisor, Earth Sciences Sector
Natural Resources Canada / Government of Canada
joost.vanulden@canada.ca / Tel: 778-960-9248

Conseiller à la gestion de projets, Secteur des sciences de la Terre
Ressources naturelles Canada / Gouvernement du Canada
joost.vanulden@canada.ca / Tél. : 778-960-9248

RE: Module Development - Advice Needed

["Van Ulden, Joost (NRCan/RNCan)" <jo...@canada.ca>]

Thanks everyone for your input.

We have created a GitHub repo for the module work here: https://github.com/Maps4HTML/mod_mapml

We will continue to develop and support the servlet until the module has been developed, tested, and made available. Pursuing this as part of the core httpd package distribution is preferable, but we can approach this as an add-in module as well.

In the interim, we will engage via the users and module-dev lists until we have a proof-of-concept module built. That way we can focus the discussions appropriately.

Cheers,

Joost van Ulden


-----Original Message-----
From: Nick Kew [mailto:niq@apache.org] 
Sent: Friday, May 27, 2016 1:55 AM
To: dev@httpd.apache.org
Subject: Re: Module Development - Advice Needed

On Thu, 2016-05-26 at 22:44 +0000, Van Ulden, Joost (NRCan/RNCan) wrote:

> I approached a couple of folks at ApacheCon in Vancouver about some 
> work that I am involved with that would benefit from an httpd module.
> I am sending this message to the list to provide more information, and 
> to seek advice on how we should proceed.
> 
> We are developing a format we call “Map Markup Language”, or MapML.
> The objective of this format is to describe Web map semantics – that 
> is scale / zoom, projection, extent, features, styles, licenses, 
> legends in the context of a hypermedia media type that can be 
> manipulated / interacted with through the uniform interface alone.  We 
> would like to eventually register the format as text/mapml.

This is seriously interesting.  I need to take a look, and will be well pleased if I can find time to take an active interest.

> A Java servlet prototype for this functionality is available:

I have yet to look at that.  Would you plan the module and servlet to grow in parallel as alternative implementations, or each to take its own path?  Presumably there is something to be gained with the two alternative implementations?

> We would like some advice on how to proceed with the development of a 
> module. For instance should we pursue this as a third-party module?
> Can we tap into the community for development assistance if we don’t 
> have the required skills in-house? Any advice would be appreciated.

You've had a couple of suggestions from Bill: I would agree that either github or the apache incubator make sense and are options worth considering (the latter could lead to it eventually becoming a sub-project of httpd itself).

I would think, let the servlet be your guide.  If it's thriving then you have a good model.  If not, you learn lessons from it.
Either way, thanks for posting to tell us about your project!

As Jacob points out, the modules-dev list is a good resource for technical help.  It's low-traffic, but still populated by a fair few people willing and able to help.

--
Nick Kew

Re: Module Development - Advice Needed

[Nick Kew <ni...@apache.org>]

On Thu, 2016-05-26 at 22:44 +0000, Van Ulden, Joost (NRCan/RNCan) wrote:

> I approached a couple of folks at ApacheCon in Vancouver about some
> work that I am involved with that would benefit from an httpd module.
> I am sending this message to the list to provide more information, and
> to seek advice on how we should proceed.
> 
> We are developing a format we call \u201cMap Markup Language\u201d, or MapML.
> The objective of this format is to describe Web map semantics \u2013 that
> is scale / zoom, projection, extent, features, styles, licenses,
> legends in the context of a hypermedia media type that can be
> manipulated / interacted with through the uniform interface alone.  We
> would like to eventually register the format as text/mapml.

This is seriously interesting.  I need to take a look, and will
be well pleased if I can find time to take an active interest.

> A Java servlet prototype for this functionality is available:

I have yet to look at that.  Would you plan the module and servlet
to grow in parallel as alternative implementations, or each to take
its own path?  Presumably there is something to be gained with the
two alternative implementations?

> We would like some advice on how to proceed with the development of a
> module. For instance should we pursue this as a third-party module?
> Can we tap into the community for development assistance if we don\u2019t
> have the required skills in-house? Any advice would be appreciated.

You've had a couple of suggestions from Bill: I would agree that
either github or the apache incubator make sense and are options
worth considering (the latter could lead to it eventually becoming
a sub-project of httpd itself).

I would think, let the servlet be your guide.  If it's thriving
then you have a good model.  If not, you learn lessons from it.
Either way, thanks for posting to tell us about your project!

As Jacob points out, the modules-dev list is a good resource
for technical help.  It's low-traffic, but still populated by
a fair few people willing and able to help.

-- 
Nick Kew

Re: Module Development - Advice Needed

[Jacob Champion <ch...@gmail.com>]

On 05/26/2016 08:18 PM, William A Rowe Jr wrote:
> The users list is the best place to ask for clarification and guidance,
> users are not exclusively admins, they include module authors,
> troubleshooters, even a testing community.

In addition to users@, there is also a modules-dev@ list for httpd. It 
has the advantage of being more tailored to module writers, and the 
disadvantage of being very, very quiet.

--Jacob

Re: Module Development - Advice Needed

[William A Rowe Jr <wr...@rowe-clan.net>]

On May 26, 2016 5:44 PM, "Van Ulden, Joost (NRCan/RNCan)" <
joost.vanulden@canada.ca> wrote:
>
> We want to develop an httpd module, “mod_mapml” which will allow the
admin to configure MapML responses over a map tile cache, using one or more
URI templates as configuration parameters.  A Java servlet prototype for
this functionality is available: https://github.com/Maps4HTML/MapMLServer.
(For the servlet, the parameters are passed via web.xml).

> We would like some advice on how to proceed with the development of a
module. For instance should we pursue this as a third-party module? Can we
tap into the community for development assistance if we don’t have the
required skills in-house? Any advice would be appreciated.

The users list is the best place to ask for clarification and guidance,
users are not exclusively admins, they include module authors,
troubleshooters, even a testing community.

I'd suggest starting with a clearly licensed github repo of your efforts
and encourage others to help fom the start in a public way.

Httpd project here has two paths, we have the core httpd package
distribution, but we have also championed add in modules.  An example would
be mod_proxy_fcgi, which is in the core bundle, and mod_fcgid, which is a
separate download.

It is probably easier to ask dev to consider your module for project
adoption here once there is a proof of concept/first draft of the working
module.  There are hundreds of third party modules, and we adopt relatively
few of these, but you should be able to create a community around your
efforts whether it is at this project, or external.

Yet another option is incubator.apache.org, and launch an independent
project as the add in module, under the Apache License 2.0 and the Apache
governance model.  The general@incubator.apache.org list is the starting
point for all such efforts.  If you were targeting httpd plus other server
frameworks, it is probably the best fit at the ASF.

Cheers

Bill