imported>Luciano: Created page with "The use of relation type "collection" is considered wrong for OSM data. The underlying philosophy is that "[http://wiki.openstreetmap.org/wiki/Relations/Relations_are_not_Cate..."

2019-03-31T19:34:56Z

Created page with "The use of relation type "collection" is considered wrong for OSM data. The underlying philosophy is that "[http://wiki.openstreetmap.org/wiki/Relations/Relations_are_not_Cate..."

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The use of relation type "collection" is considered wrong for OSM data. The underlying philosophy is that "[http://wiki.openstreetmap.org/wiki/Relations/Relations_are_not_Categories relations are not categories]."

However, there are much more extensive resources for making detailed queries against the "live," current OSM data than there are in OGF. Thus, for example, suppose I have done a bunch of river work in my country, Ardisphere, and I want to get an OSM file that has the river data but not all the other stuff (because to get the whole country makes for a much too massive file!). I have to wait 24 hours (or more) for a backup file, and do an extract.

Alternately, by using ''collection'' relations, I can immediately download my rivers in JOSM by using the "download object" feature, as long as I'm making sure I add my rivers to the correct "rivers" collection relation as I edit them.

Further, I have found that by holding a set of objects (nodes, ways, relations) in a collection in this way, I can use the External Data Mediawiki extension to directly query the OGF database and present the resulting information in a wiki table. The below table is in fact an example of this query process. The data in the table is not in the wiki - it's being queried "live" (with a caching delay) from the "map."

::''The following data has been retrieved from [https://opengeofiction.net/api/0.6/relation/6408/full this URL], using the [http://www.mediawiki.org/wiki/Extension:External_Data External Data] MediaWiki extension.''
</span>}}}</span>{{#clear_external_data:}}
{{#get_web_data:url=https://opengeofiction.net/api/0.6/relation/6408/full
|format=xml
|data=
relation_id=/osm/relation/@id
,type=/osm/relation/tag[@k='ogf:type']/@v
,note=/osm/relation/tag[@k='note']/@v
|use xpath
}}
{| class="wikitable sortable"
! OGF Type
! Relation
! Description
{{#for_external_table:<nowiki/>
{{!}}-
{{!}}{{{type}}}
{{!}}[https://opengeofiction.net/relation/{{{relation_id}}} (relation {{{relation_id}}})]
{{!}}{{{note}}}
}}
|}

User:Luciano/Sandbox/Collections - Revision history

imported>Luciano: Created page with "The use of relation type "collection" is considered wrong for OSM data. The underlying philosophy is that "[http://wiki.openstreetmap.org/wiki/Relations/Relations_are_not_Cate..."