[Openstreetmap-dev] More on GPX schema

Frank Mohr f_mohr at yahoo.de
Thu Sep 22 12:39:42 BST 2005


immanuel.scholz at gmx.de wrote:
> Hi,
> 
> 
> 
>>to make it distinguishable we might use something like:
>>
>><trk>
>><number>50521</number>
>>  <name>Lodge Road</name>
>>  <extensions>
>>  <osm:permissions>
>>    <osm name="foot" value="yes" />
>>    <!-- or -->
>>    <osm:foot>yes</osm:foot>
>>    <!-- or simply list only the "true" values -->
>>    <osm:foot />
>>  </osm:permissions>
>>  <osm:class>secondary</class>
>></extensions>
> 
> 
> About the different tags: Do you mean deliver all three variants in
> one file every time? I hope not.

no .. these where just differnt examples

> To promote my version again (the first one):
> If you choose the keys as tagnames, you are limited to key names
> that fit in the definition of a tagname (no special characters like
> áä°, no whitespaces etc..) and you are unable to add other tagnames
> for other features later without complicating your style definition
> by a list of crude exceptions.

depends ..
i'd prefer a limited set of predefined tag names for data exchange
For users those tag names might be translated to something more readable
(or in different languages)
i started a dictionary for this purpose on
http://www.openstreetmap.org/wiki/index.php/Dictionary

> Next thing to comment is the auto-conversion of "yes" to the pure
> existence of the tag (the last one):
> I don't think it is the responsibility of the database server to
> interprete the values. If some application make a difference of "yes" and
> "1", it is there problem (at last, somewhere in your special file
> mentioned later, it is defined that "yes" and "1" are the same thing). But
> by not integrate the value interpretion into the structure, you are free
> to add better interpretations later.
> 
> As example, some user may set the "foot" to "during summer". The
> metadata-file state that "during summer" equals to "yes". But some
> applications display streets that are only sometimes accessible by foot
> with a dashed line etc..

right ..

>>>How do you going to transfer key:"foo", value:"bar" ? as <foo>bar</bar> ?
>>>Or maybe as <unknown foo="bar" /> ?
>>
>>currently they are not defined in the upload, but on a special page
>>(at least last time i checked this)
> 
> 
> So the xml-structure would not be static defined, but are constructed
> by a dynamic changing page you have to parse every time before you can
> talk to the server?
> 
> To me, this looks VERY complicated compared to just list the key/value
> pairs as data (not as tagnames) in the extensions-tag.

it is .. i had to look at the page source to get the numerical values
for the keys for my Perl XMLRPC lib.
(page is gone ... was on the editor pages)
here a predifined XML schema would help

> PS: Maybe my understanding of OSM is completly off the reality. I am
> relative new to the project (and didn't contribute any remarkable yet
> either). I even did not understand the full key/value system Steve planned
> to use (he promised me to update the wiki-page about it, but nothing's
> done yet.. hinthinthint ;-)

just another request @ Steve :
do we have a documentation of the database?
this would help in the discussion and in defining the gpx extensions

frank

	

	
		
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