Add `webmap-publish` script to export layers to Mapbox Vector Tiles.

1 files changed, 11 insertions, 103 deletions

diff --git a/webmap-import b/webmap-import
index bfee9dc..74b6ed5 100755
--- a/webmap-import
+++ b/webmap-import
@@ -38,7 +38,6 @@ from osgeo.gdalconst import (
     OF_VERBOSE_ERROR as GDAL_OF_VERBOSE_ERROR,
     CE_None as GDAL_CE_None,
     DCAP_CREATE as GDAL_DCAP_CREATE,
-    DCAP_VECTOR as GDAL_DCAP_VECTOR,
     DCAP_DEFAULT_FIELDS as GDAL_DCAP_DEFAULT_FIELDS,
     DCAP_NOTNULL_FIELDS as GDAL_DCAP_NOTNULL_FIELDS,
     DCAP_UNIQUE_FIELDS as GDAL_DCAP_UNIQUE_FIELDS,
@@ -47,40 +46,13 @@ import osgeo.gdalconst as gdalconst
 gdal.UseExceptions()
 
 import common
-
-# Wrapper around gdal.MajorObject.GetMetadataItem(name)
-def getMetadataItem(o, k):
-    v = o.GetMetadataItem(k)
-    if v is not None and isinstance(v, str):
-        return v.upper() == 'YES'
-    else:
-        return False
-
-# Return kwargs and driver for OpenEx()
-def setOpenExArgs(option_dict, flags=0):
-    kwargs = { 'nOpenFlags': GDAL_OF_VECTOR | flags }
-
-    fmt = option_dict.get('format', None)
-    if fmt is None:
-        drv = None
-    else:
-        drv = gdal.GetDriverByName(fmt)
-        if drv is None:
-            raise Exception(f'Unknown driver name "{fmt}"')
-        elif not getMetadataItem(drv, GDAL_DCAP_VECTOR):
-            raise Exception(f'Driver "{drv.ShortName}" has no vector capabilities')
-        kwargs['allowed_drivers'] = [ drv.ShortName ]
-
-    oo = option_dict.get('open-options', None)
-    if oo is not None:
-        kwargs['open_options'] = [ k + '=' + str(v) for k, v in oo.items() ]
-    return kwargs, drv
+from common import gdalSetOpenExArgs, gdalGetMetadataItem, gdalVersionMin, escapeIdentifier
 
 # Open and return the output DS.  It is created if create=False or
 # create-options is a non-empty dictionary.
 def openOutputDS(def_dict):
     path = def_dict['path']
-    kwargs, drv = setOpenExArgs(def_dict, flags=GDAL_OF_UPDATE|GDAL_OF_VERBOSE_ERROR)
+    kwargs, drv = gdalSetOpenExArgs(def_dict, flags=GDAL_OF_UPDATE|GDAL_OF_VERBOSE_ERROR)
     try:
         logging.debug('OpenEx(%s, %s)', path, str(kwargs))
         return gdal.OpenEx(path, **kwargs)
@@ -111,7 +83,7 @@ def openOutputDS(def_dict):
         if not def_dict.get('create', False) and dsco is None:
             # not configured for creation
             raise e
-        if drv is None or not getMetadataItem(drv, GDAL_DCAP_CREATE):
+        if drv is None or not gdalGetMetadataItem(drv, GDAL_DCAP_CREATE):
             # not capable of creation
             raise e
 
@@ -349,13 +321,13 @@ def setFieldIf(cond, attrName, val, data, fldName, drvName, log=logging.warning)
 # constraints.)
 def validateSchema(layers, drvo=None, lco_defaults=None):
     # Cf. https://github.com/OSGeo/gdal/blob/master/NEWS.md
-    if common.gdal_version_min(maj=3, min=7):
+    if gdalVersionMin(maj=3, min=7):
         # list of capability flags supported by the CreateField() API
         drvoFieldDefnFlags = drvo.GetMetadataItem(gdalconst.DMD_CREATION_FIELD_DEFN_FLAGS)
         drvoFieldDefnFlags = drvoFieldDefnFlags.split(' ') if drvoFieldDefnFlags is not None else []
         drvoSupportsFieldComment = 'Comment' in drvoFieldDefnFlags
         # GetTZFlag()/SetTZFlag() and OGR_TZFLAG_* constants added in 3.8.0
-        hasTZFlagSupport = common.gdal_version_min(maj=3, min=8)
+        hasTZFlagSupport = gdalVersionMin(maj=3, min=8)
     else:
         # list of flags supported by the OGRLayer::AlterFieldDefn() API
         drvoFieldDefnFlags = drvo.GetMetadataItem(gdalconst.DMD_ALTER_FIELD_DEFN_FLAGS)
@@ -366,9 +338,9 @@ def validateSchema(layers, drvo=None, lco_defaults=None):
 
     # cache driver capabilities
     drvoSupportsFieldWidthPrecision = 'WidthPrecision' in drvoFieldDefnFlags
-    drvoSupportsFieldNullable = 'Nullable' in drvoFieldDefnFlags and getMetadataItem(drvo, GDAL_DCAP_NOTNULL_FIELDS)
-    drvoSupportsFieldUnique   = 'Unique'   in drvoFieldDefnFlags and getMetadataItem(drvo, GDAL_DCAP_UNIQUE_FIELDS)
-    drvoSupportsFieldDefault  = 'Default'  in drvoFieldDefnFlags and getMetadataItem(drvo, GDAL_DCAP_DEFAULT_FIELDS)
+    drvoSupportsFieldNullable = 'Nullable' in drvoFieldDefnFlags and gdalGetMetadataItem(drvo, GDAL_DCAP_NOTNULL_FIELDS)
+    drvoSupportsFieldUnique   = 'Unique'   in drvoFieldDefnFlags and gdalGetMetadataItem(drvo, GDAL_DCAP_UNIQUE_FIELDS)
+    drvoSupportsFieldDefault  = 'Default'  in drvoFieldDefnFlags and gdalGetMetadataItem(drvo, GDAL_DCAP_DEFAULT_FIELDS)
     drvoSupportsFieldAlternativeName = 'AlternativeName' in drvoFieldDefnFlags
 
     for layername, layerdef in layers.items():
@@ -450,62 +422,6 @@ def validateSchema(layers, drvo=None, lco_defaults=None):
 
                 fields[idx] = fld_def2
 
-# Return the decoded Spatial Reference System
-def getSRS(srs_str):
-    if srs_str is None:
-        return
-    srs = osr.SpatialReference()
-    if srs_str.startswith('EPSG:'):
-        code = int(srs_str.removeprefix('EPSG:'))
-        srs.ImportFromEPSG(code)
-    else:
-        raise Exception(f'Unknown SRS {srs_str}')
-    logging.debug('Default SRS: "%s" (%s)', srs.ExportToProj4(), srs.GetName())
-    return srs
-
-# Convert extent [minX, minY, maxX, maxY] into a polygon and assign the
-# given SRS.  Like apps/ogr2ogr_lib.cpp, we segmentize the polygon to
-# make sure it is sufficiently densified when transforming to source
-# layer SRS for spatial filtering.
-def getExtent(extent, srs=None):
-    if extent is None:
-        return
-
-    if not (isinstance(extent, list) or isinstance(extent, tuple)) or len(extent) != 4:
-        raise Exception(f'Invalid extent {extent}')
-    elif srs is None:
-        raise Exception('Configured extent but no SRS')
-
-    logging.debug('Configured extent in %s: %s',
-        srs.GetName(), ', '.join(map(str, extent)))
-
-    ring = ogr.Geometry(ogr.wkbLinearRing)
-    ring.AddPoint_2D(extent[0], extent[1])
-    ring.AddPoint_2D(extent[2], extent[1])
-    ring.AddPoint_2D(extent[2], extent[3])
-    ring.AddPoint_2D(extent[0], extent[3])
-    ring.AddPoint_2D(extent[0], extent[1])
-
-    polygon = ogr.Geometry(ogr.wkbPolygon)
-    polygon.AddGeometry(ring)
-
-    # we expressed extent as minX, minY, maxX, maxY (easting/northing
-    # ordered, i.e., in traditional GIS order)
-    srs2 = srs.Clone()
-    srs2.SetAxisMappingStrategy(osr.OAMS_TRADITIONAL_GIS_ORDER)
-    polygon.AssignSpatialReference(srs2)
-    polygon.TransformTo(srs)
-
-    segment_distance_metre = 10 * 1000
-    if srs.IsGeographic():
-        dfMaxLength = segment_distance_metre / math.radians(srs.GetSemiMajor())
-        polygon.Segmentize(dfMaxLength)
-    elif srs.IsProjected():
-        dfMaxLength = segment_distance_metre / srs.GetLinearUnits()
-        polygon.Segmentize(dfMaxLength)
-
-    return polygon
-
 # Validate the output layer against the provided SRS and creation options
 def validateOutputLayer(lyr, srs=None, options=None):
     ok = True
@@ -799,14 +715,6 @@ def setOutputFieldMap(defn, sources):
                         rule['replace'] = re.compile(rule['replace'])
                     rules[idx] = ( rule['replace'], rule['with'] )
 
-# Escape the given identifier, cf.
-# swig/python/gdal-utils/osgeo_utils/samples/validate_gpkg.py:_esc_id()
-def escapeIdentifier(identifier):
-    if '\x00' in identifier:
-        raise Exception(f'Invalid identifier "{identifier}"')
-    # SQL:1999 delimited identifier
-    return '"' + identifier.replace('"', '""') + '"'
-
 # Clear the given layer (wipe all its features)
 def clearLayer(ds, lyr):
     n = -1
@@ -938,7 +846,7 @@ def setFieldMapValue(fld, idx, val):
 # while we want a single transaction for the entire desination layer,
 # including truncation, source imports, and metadata changes.
 def importSource2(lyr_dst, path, args={}, basedir=None, extent=None):
-    kwargs, _ = setOpenExArgs(args, flags=GDAL_OF_READONLY|GDAL_OF_VERBOSE_ERROR)
+    kwargs, _ = gdalSetOpenExArgs(args, flags=GDAL_OF_READONLY|GDAL_OF_VERBOSE_ERROR)
     path2 = path if basedir is None else str(basedir.joinpath(path))
 
     logging.debug('OpenEx(%s, %s)', path2, str(kwargs))
@@ -1245,8 +1153,8 @@ if __name__ == '__main__':
         lco_defaults=common.config['dataset'].get('create-layer-options', None))
 
     # get configured Spatial Reference System and extent
-    srs = getSRS(common.config.get('SRS', None))
-    extent = getExtent(common.config.get('extent', None), srs=srs)
+    srs = common.getSRS(common.config.get('SRS', None))
+    extent = common.getExtent(common.config.get('extent', None), srs=srs)[0]
 
     if args.lockfile is not None:
         # obtain an exclusive lock and don't release it until exiting the program