Check for Direct Links to Data¶
This FGDC conformance check verifies that links to a zip file contain geospatial data.
Direct Data Links¶
This FGDC conformance check gets the last 100 bytes using an HTTP Range request to read the end-of-central-directory (EOCD) section in a target zip file. The EOCD section contains a complete file listing and file byte offsets in the ZIP. File listings are then verified to have a geospatial extension.
Recognized File Extensions¶
gpkg
shp
gdb
geojson
kmz
kml
gml
gpx
vct
tab
osm
dlg
img
asc
tif
rst
pix
ecw
jp2
sid
mdb
mbtiles
vmds
sqlite
las
laz
xyz
dem
hdf
It is important to note that enabling the HTTP Range header is completely optional for caching data in Geoplatform.
Besides enabling Range header on the server, some other reasons this rule may fail:
No ZIP64 support
No encrypted ZIP support
No stream support
Long comments in a ZIP file
ISO 19115¶
//gmd:transferOptions/gmd:MD_DigitalTransferOptions/gmd:onLine/gmd:CI_OnlineResource/gmd:linkage/gmd:URL/text()
ISO 19115-3¶
//mrd:transferOptions/mrd:MD_DigitalTransferOptions/mrd:onLine/cit:CI_OnlineResource/cit:linkage/gco:CharacterString/text()