[OSM-talk] Milestone

[Andy Allan]

On Fri, Aug 1, 2008 at 10:19 AM, Steve Chilton <S.L.Chilton at mdx.ac.uk> wrote:
> Andy
>
> Have looked at the link on mapnik pages and can see real benefit in
> defining colours once, and icon paths. Much of the layer
> identification/specification stuff is ripe for enter once/repeat too.

Cool.

> Not so sure how splitting file into layers files would work in practice
> - they would have to be continually merged to test render changes as far
> as I can see, although if possible would make understanding and working
> with the code possibly a lot easier.

As well as just variables, whole files can be included ("External
Entities"). So perhaps you could have a master file containing
&roads;
&railways;
&contours;
...etc...
refering to seperate roads.xml.inc, railways.xml.inc and so on. Not
huge amounts of point on their own, but it would make it easy to mix
and match if we had
&steve8s_roads;
&harrys_rafting;
&andys_contours;
&my_own_whatevers;

... and then you'd only have to worry about your own whatevers.xml.inc
file and simply update the others, instead of trying to get your head
round diffs and merging and editing of one 5.2 kiloline file.

> How long are you going to be in Aberdeen for SoC conf? Maybe we could
> put some time aside to work together on this (3 weeks holiday before
> then so no spare time) - eg the Tuesday afternoon.

Sounds like a good idea - I'll try some experiments before then and
see how it goes.

Cheers,
Andy

> NB: my main requirement is less fiddling with colours and more adding
> new features in AND getting them in the right relative place in the
> painting/stacking process.
>
> Cheers
> STEVE
>
> Steve Chilton, Learning Support Fellow
> Manager of e-Learning Academic Development
> Centre for Learning and Quality Enhancement
> Middlesex University
> phone/fax: 020 8411 5355
> email: steve8 at mdx.ac.uk
> http://www.mdx.ac.uk/schools/hssc/staff/profiles/technical/chiltons.asp
>
> Chair of the Society of Cartographers: http://www.soc.org.uk/
>
> SoC conference 2008:
> http://www.abdn.ac.uk/cartographers08/
> -----Original Message-----
> From: Andy Allan [mailto:gravitystorm at gmail.com]
> Sent: 31 July 2008 18:09
> To: Steve Chilton
> Cc: talk at openstreetmap.org
> Subject: Re: [OSM-talk] Milestone
>
> On Mon, Jul 28, 2008 at 6:47 PM, Steve Chilton <S.L.Chilton at mdx.ac.uk>
> wrote:
>
>> So, if anyone feels like getting their hands dirty and doing some
> collaborative work on mapnik style improvements then just drop me a
> line.
>
> I've spent quite a while making maps based on the osm.xml file - not
> just the cycle map, but others too - and it's a bit of a pain* to
> maintain a fork or even just use the main one as a base to work from.
> I wonder if making this easier will build more of a community around
> the mapnik stylesheet and therefore get more things fed back in.
>
> So what does everyone think about raising the minimum requirements to
> mapnik + libxml xmparser support**? For the basics, that would allow
> defining all the colours in one place at the top of the file (and only
> use each hex code once***). Most of what I've seen people wanting to
> do is fiddle with the colours and it's currently pretty hard to do,
> and a pain to keep in sync.
>
> Beyond that, we could look at splitting layers into separate files,
> again for ease of following changes since diffs of large repetitive
> files can be erratic (and editing too, I would suspect, since I often
> lose track of whether I'm in the middle of a roads-casing or
> minor-roads-fill stylename).
>
> Thoughts?
>
> Andy
>
> * Understatement
> ** http://trac.mapnik.org/wiki/ManagingLargeXmlFiles
> *** for example: "grep '809bc0' osm.xml | wc -l" alone gives 30
> recurrences
>
>
>