import os from math import ceil from urllib2 import urlopen, HTTPError, URLError import grass.script as grass from grass.exceptions import CalledModuleError class WFSBase: def __init__(self): # these variables are information for destructor self.temp_to_cleanup = [] self.bbox = None self.temp_map = None def __del__(self): # tries to remove temporary files/dirs, all temps should be # removoved before, implemented just in case of unexpected # stop of module for temp in self.temp_to_cleanup: if os.path.isdir(temp): grass.try_rmdir(temp) else: grass.try_remove(temp) # deletes enviromental variable which overrides region if 'GRASS_REGION' in os.environ.keys(): os.environ.pop('GRASS_REGION') def _debug(self, fn, msg): grass.debug("%s.%s: %s" % (self.__class__.__name__, fn, msg)) def _initializeParameters(self, options, flags): self._debug("_initialize_parameters", "started") # initialization of module parameters (options, flags) self.o_url = options['url'].strip() + "?" self.o_layers = options['layers'].strip() self.o_output = options['output'] self.o_wds_version = options['wfs_version'] self.projection_name = "SRSNAME" self.o_wfs_version = options['wfs_version'] self.o_urlparams = options['urlparams'].strip() self.o_srs = int(options['srs']) if self.o_srs <= 0: grass.fatal(_("Invalid EPSG code %d") % self.o_srs) try: self.o_maximum_features = int(options['maximum_features']) if int(options['maximum_features']) < 1: grass.fatal(_('Invalid maximum number of features (must be >1)')) except ValueError: self.o_maximum_features = None # read projection info self.proj_location = grass.read_command('g.proj', flags ='jf').rstrip('\n') self.proj_srs = grass.read_command('g.proj', flags = 'jf', epsg = str(self.o_srs) ).rstrip('\n') if not self.proj_srs or not self.proj_location: grass.fatal(_("Unable to get projection info")) # set region self.o_region = options['region'] if self.o_region: if not grass.find_file(name = self.o_region, element = 'windows', mapset = '.' )['name']: grass.fatal(_("Region <%s> not found") % self.o_region) if self.o_region: s = grass.read_command('g.region', quiet = True, flags = 'ug', region = self.o_region) self.region = grass.parse_key_val(s, val_type = float) else: self.region = grass.region() self.ogr_drv_format = "ESRI Shapefile" self._debug("_initialize_parameters", "finished") def GetFeature(self, options, flags): """!Download data from WFS server and import data into GRASS as a vector map.""" self._initializeParameters(options, flags) if flags['r']: self.bbox = self._computeBbox() else: self.bbox = None self.temp_map = self._download() self._createOutputMap() def GetCapabilities(self, options): """!Get capabilities from WFS server """ # download capabilities file cap_url = options['url'] + "?service=WFS&request=GetCapabilities&version=" + options['wfs_version'] try: cap = urlopen(cap_url) except IOError: grass.fatal(_("Unable to get capabilities from '%s'") % options['url']) cap_lines = cap.readlines() for line in cap_lines: print(line) def _computeBbox(self): """!Get region extent for WFS query (bbox) """ self._debug("_computeBbox", "started") bbox_region_items = {'maxy' : 'n', 'miny' : 's', 'maxx' : 'e', 'minx' : 'w'} bbox = {} if self.proj_srs == self.proj_location: # TODO: do it better for bbox_item, region_item in bbox_region_items.iteritems(): bbox[bbox_item] = self.region[region_item] # if location projection and wfs query projection are # different, corner points of region are transformed into wfs # projection and then bbox is created from extreme coordinates # of the transformed points else: for bbox_item, region_item in bbox_region_items.iteritems(): bbox[bbox_item] = None temp_region = self._temp() try: temp_region_opened = open(temp_region, 'w') temp_region_opened.write("%f %f\n%f %f\n%f %f\n%f %f\n" %\ (self.region['e'], self.region['n'],\ self.region['w'], self.region['n'],\ self.region['w'], self.region['s'],\ self.region['e'], self.region['s'] )) except IOError: grass.fatal(_("Unable to write data into tempfile")) finally: temp_region_opened.close() points = grass.read_command('m.proj', flags = 'd', proj_out = self.proj_srs, proj_in = self.proj_location, input = temp_region) # TODO: stdin grass.try_remove(temp_region) if not points: grass.fatal(_("Unable to determine region, %s failed") % 'm.proj') points = points.splitlines() if len(points) != 4: grass.fatal(_("Region defintion: 4 points required")) for point in points: point = map(float, point.split("|")) if not bbox['maxy']: bbox['maxy'] = point[1] bbox['miny'] = point[1] bbox['maxx'] = point[0] bbox['minx'] = point[0] continue if bbox['maxy'] < point[1]: bbox['maxy'] = point[1] elif bbox['miny'] > point[1]: bbox['miny'] = point[1] if bbox['maxx'] < point[0]: bbox['maxx'] = point[0] elif bbox['minx'] > point[0]: bbox['minx'] = point[0] self._debug("_computeBbox", "finished -> %s" % bbox) # Ordering of coordinates axis of geographic coordinate # systems is fliped If self.flip_coords is # True, coords in bbox need to be flipped in WFS query. self.flip_coords = False hasLongLat = self.proj_srs.find("+proj=longlat") hasLatLong = self.proj_srs.find("+proj=latlong") if (hasLongLat != -1 or hasLatLong != -1): self.flip_coords = True return bbox def _createOutputMap(self): """!Import downloaded data into GRASS, reproject data if needed using ogr2ogr """ # reprojection of downloaded data if self.proj_srs != self.proj_location: # TODO: do it better grass.message(_("Reprojecting data...")) temp_warpmap = self._temp() if int(os.getenv('GRASS_VERBOSE', '2')) <= 2: nuldev = file(os.devnull, 'w+') else: nuldev = None temp_warpmap = self._temp(directory = True) ps = grass.Popen(['ogr2ogr', '-overwrite', '-s_srs', '%s' % self.proj_srs, '-t_srs', '%s' % self.proj_location, '-f', '%s' % self.ogr_drv_format, temp_warpmap, self.temp_map], stdout = nuldev) ps.wait() if nuldev: nuldev.close() if ps.returncode != 0: grass.fatal(_('%s failed') % 'ogr2ogr') # downloaded data projection is same as projection of location else: temp_warpmap = self.temp_map grass.message(_("Importing vector map into GRASS...")) # importing temp_map into GRASS try: grass.run_command('v.in.ogr', quiet = True, overwrite = True, input = temp_warpmap, output = self.o_output) except CalledModuleError: grass.fatal(_('%s failed') % 'v.in.ogr') grass.try_rmdir(temp_warpmap) grass.try_remove(self.temp_map) def _flipBbox(self, bbox): """ flips items in dictionary value flips between this keys: maxy -> maxx maxx -> maxy miny -> minx minx -> miny @return copy of bbox with fliped cordinates """ temp_bbox = dict(bbox) new_bbox = {} new_bbox['maxy'] = temp_bbox['maxx'] new_bbox['miny'] = temp_bbox['minx'] new_bbox['maxx'] = temp_bbox['maxy'] new_bbox['minx'] = temp_bbox['miny'] return new_bbox def _temp(self, directory = False): """!Create temp file/dir and append list self.temp_to_cleanup with the file/dir path @param directory if False create file, if True create directory @return string path to temp """ if directory: temp = grass.tempdir() else: temp = grass.tempfile() if temp is None: grass.fatal(_("Unable to create temporary files")) # list of created temps for destructor self.temp_to_cleanup.append(temp) return temp