# -*- coding: ISO-8859-15 -*- # ============================================================================= # Copyright (c) 2004, 2006 Sean C. Gillies # Copyright (c) 2007 STFC # # Authors : # Dominic Lowe # # Contact email: d.lowe@rl.ac.uk # ============================================================================= from __future__ import (absolute_import, division, print_function) from owslib.coverage.wcsBase import WCSBase, WCSCapabilitiesReader, ServiceException try: from urllib import urlencode except ImportError: from urllib.parse import urlencode from owslib.util import openURL, testXMLValue from owslib.etree import etree from owslib.crs import Crs import os, errno import logging from owslib.util import log # function to save writing out WCS namespace in full each time def ns(tag): return '{http://www.opengis.net/wcs}'+tag class WebCoverageService_1_0_0(WCSBase): """Abstraction for OGC Web Coverage Service (WCS), version 1.0.0 Implements IWebCoverageService. """ def __getitem__(self,name): ''' check contents dictionary to allow dict like access to service layers''' if name in self.__getattribute__('contents').keys(): return self.__getattribute__('contents')[name] else: raise KeyError("No content named %s" % name) def __init__(self,url,xml, cookies): self.version='1.0.0' self.url = url self.cookies=cookies # initialize from saved capability document or access the server reader = WCSCapabilitiesReader(self.version, self.cookies) if xml: self._capabilities = reader.readString(xml) else: self._capabilities = reader.read(self.url) # check for exceptions se = self._capabilities.find('ServiceException') if se is not None: err_message = str(se.text).strip() raise ServiceException(err_message, xml) #serviceIdentification metadata subelem=self._capabilities.find(ns('Service')) self.identification=ServiceIdentification(subelem) #serviceProvider metadata subelem=self._capabilities.find(ns('Service/')+ns('responsibleParty')) self.provider=ServiceProvider(subelem) #serviceOperations metadata self.operations=[] for elem in self._capabilities.find(ns('Capability/')+ns('Request'))[:]: self.operations.append(OperationMetadata(elem)) #serviceContents metadata self.contents={} for elem in self._capabilities.findall(ns('ContentMetadata/')+ns('CoverageOfferingBrief')): cm=ContentMetadata(elem, self) self.contents[cm.id]=cm #Some WCS servers (wrongly) advertise 'Content' OfferingBrief instead. if self.contents=={}: for elem in self._capabilities.findall(ns('ContentMetadata/')+ns('ContentOfferingBrief')): cm=ContentMetadata(elem, self) self.contents[cm.id]=cm #exceptions self.exceptions = [f.text for f \ in self._capabilities.findall('Capability/Exception/Format')] def items(self): '''supports dict-like items() access''' items=[] for item in self.contents: items.append((item,self.contents[item])) return items def __makeString(self,value): #using repr unconditionally breaks things in some circumstances if a value is already a string if type(value) is not str: sval=repr(value) else: sval = value return sval def getCoverage(self, identifier=None, bbox=None, time=None, format = None, crs=None, width=None, height=None, resx=None, resy=None, resz=None,parameter=None,method='Get',**kwargs): """Request and return a coverage from the WCS as a file-like object note: additional **kwargs helps with multi-version implementation core keyword arguments should be supported cross version example: cvg=wcs.getCoverage(identifier=['TuMYrRQ4'], timeSequence=['2792-06-01T00:00:00.0'], bbox=(-112,36,-106,41),format='cf-netcdf') is equivalent to: http://myhost/mywcs?SERVICE=WCS&REQUEST=GetCoverage&IDENTIFIER=TuMYrRQ4&VERSION=1.1.0&BOUNDINGBOX=-180,-90,180,90&TIME=2792-06-01T00:00:00.0&FORMAT=cf-netcdf """ if log.isEnabledFor(logging.DEBUG): log.debug('WCS 1.0.0 DEBUG: Parameters passed to GetCoverage: identifier=%s, bbox=%s, time=%s, format=%s, crs=%s, width=%s, height=%s, resx=%s, resy=%s, resz=%s, parameter=%s, method=%s, other_arguments=%s'%(identifier, bbox, time, format, crs, width, height, resx, resy, resz, parameter, method, str(kwargs))) try: base_url = next((m.get('url') for m in self.getOperationByName('GetCoverage').methods if m.get('type').lower() == method.lower())) except StopIteration: base_url = self.url if log.isEnabledFor(logging.DEBUG): log.debug('WCS 1.0.0 DEBUG: base url of server: %s'%base_url) #process kwargs request = {'version': self.version, 'request': 'GetCoverage', 'service':'WCS'} assert len(identifier) > 0 request['Coverage']=identifier #request['identifier'] = ','.join(identifier) if bbox: request['BBox']=','.join([self.__makeString(x) for x in bbox]) else: request['BBox']=None if time: request['time']=','.join(time) if crs: request['crs']=crs request['format']=format if width: request['width']=width if height: request['height']=height if resx: request['resx']=resx if resy: request['resy']=resy if resz: request['resz']=resz #anything else e.g. vendor specific parameters must go through kwargs if kwargs: for kw in kwargs: request[kw]=kwargs[kw] #encode and request data = urlencode(request) if log.isEnabledFor(logging.DEBUG): log.debug('WCS 1.0.0 DEBUG: Second part of URL: %s'%data) u=openURL(base_url, data, method, self.cookies) return u def getOperationByName(self, name): """Return a named operation item.""" for item in self.operations: if item.name == name: return item raise KeyError("No operation named %s" % name) class OperationMetadata(object): """Abstraction for WCS metadata. Implements IMetadata. """ def __init__(self, elem): """.""" self.name = elem.tag.split('}')[1] #self.formatOptions = [f.text for f in elem.findall('{http://www.opengis.net/wcs/1.1/ows}Parameter/{http://www.opengis.net/wcs/1.1/ows}AllowedValues/{http://www.opengis.net/wcs/1.1/ows}Value')] self.methods = [] for resource in elem.findall(ns('DCPType/')+ns('HTTP/')+ns('Get/')+ns('OnlineResource')): url = resource.attrib['{http://www.w3.org/1999/xlink}href'] self.methods.append({'type': 'Get', 'url': url}) for resource in elem.findall(ns('DCPType/')+ns('HTTP/')+ns('Post/')+ns('OnlineResource')): url = resource.attrib['{http://www.w3.org/1999/xlink}href'] self.methods.append({'type': 'Post', 'url': url}) class ServiceIdentification(object): """ Abstraction for ServiceIdentification metadata """ def __init__(self,elem): # properties self.type='OGC:WCS' self.version='1.0.0' self.service = testXMLValue(elem.find(ns('name'))) self.abstract = testXMLValue(elem.find(ns('description'))) self.title = testXMLValue(elem.find(ns('label'))) self.keywords = [f.text for f in elem.findall(ns('keywords')+'/'+ns('keyword'))] #note: differs from 'rights' in interface self.fees=elem.find(ns('fees')).text self.accessConstraints=elem.find(ns('accessConstraints')).text class ServiceProvider(object): """ Abstraction for WCS ResponsibleParty Implements IServiceProvider""" def __init__(self,elem): #it's not uncommon for the service provider info to be missing #so handle case where None is passed in if elem is None: self.name=None self.url=None self.contact = None else: self.name=testXMLValue(elem.find(ns('organisationName'))) self.url=self.name #there is no definitive place for url WCS, repeat organisationName self.contact=ContactMetadata(elem) class ContactMetadata(object): ''' implements IContactMetadata''' def __init__(self, elem): try: self.name = elem.find(ns('individualName')).text except AttributeError: self.name = None try: self.organization=elem.find(ns('organisationName')).text except AttributeError: self.organization = None try: self.address = elem.find(ns('contactInfo')+'/'+ns('address')+'/'+ns('deliveryPoint')).text except AttributeError: self.address = None try: self.city= elem.find(ns('contactInfo')+'/'+ns('address')+'/'+ns('city')).text except AttributeError: self.city = None try: self.region=elem.find(ns('contactInfo')+'/'+ns('address')+'/'+ns('administrativeArea')).text except AttributeError: self.region = None try: self.postcode=elem.find(ns('contactInfo')+'/'+ns('address')+'/'+ns('postalCode')).text except AttributeError: self.postcode=None try: self.country=elem.find(ns('contactInfo')+'/'+ns('address')+'/'+ns('country')).text except AttributeError: self.country = None try: self.email=elem.find(ns('contactInfo')+'/'+ns('address')+'/'+ns('electronicMailAddress')).text except AttributeError: self.email = None class ContentMetadata(object): """ Implements IContentMetadata """ def __init__(self, elem, service): """Initialize. service is required so that describeCoverage requests may be made""" #TODO - examine the parent for bounding box info. #self._parent=parent self._elem=elem self._service=service self.id=elem.find(ns('name')).text self.title = testXMLValue(elem.find(ns('label'))) self.abstract= testXMLValue(elem.find(ns('description'))) self.keywords = [f.text for f in elem.findall(ns('keywords')+'/'+ns('keyword'))] self.boundingBox=None #needed for iContentMetadata harmonisation self.boundingBoxWGS84 = None b = elem.find(ns('lonLatEnvelope')) if b is not None: gmlpositions=b.findall('{http://www.opengis.net/gml}pos') lc=gmlpositions[0].text uc=gmlpositions[1].text self.boundingBoxWGS84 = ( float(lc.split()[0]),float(lc.split()[1]), float(uc.split()[0]), float(uc.split()[1]), ) #others not used but needed for iContentMetadata harmonisation self.styles=None self.crsOptions=None self.defaulttimeposition=None #grid is either a gml:Grid or a gml:RectifiedGrid if supplied as part of the DescribeCoverage response. def _getGrid(self): if not hasattr(self, 'descCov'): self.descCov=self._service.getDescribeCoverage(self.id) gridelem= self.descCov.find(ns('CoverageOffering/')+ns('domainSet/')+ns('spatialDomain/')+'{http://www.opengis.net/gml}RectifiedGrid') if gridelem is not None: grid=RectifiedGrid(gridelem) else: gridelem=self.descCov.find(ns('CoverageOffering/')+ns('domainSet/')+ns('spatialDomain/')+'{http://www.opengis.net/gml}Grid') grid=Grid(gridelem) return grid grid=property(_getGrid, None) #timelimits are the start/end times, timepositions are all timepoints. WCS servers can declare one or both or neither of these. def _getTimeLimits(self): timepoints, timelimits=[],[] b=self._elem.find(ns('lonLatEnvelope')) if b is not None: timepoints=b.findall('{http://www.opengis.net/gml}timePosition') else: #have to make a describeCoverage request... if not hasattr(self, 'descCov'): self.descCov=self._service.getDescribeCoverage(self.id) for pos in self.descCov.findall(ns('CoverageOffering/')+ns('domainSet/')+ns('temporalDomain/')+'{http://www.opengis.net/gml}timePosition'): timepoints.append(pos) if timepoints: timelimits=[timepoints[0].text,timepoints[1].text] return timelimits timelimits=property(_getTimeLimits, None) def _getTimePositions(self): timepositions=[] if not hasattr(self, 'descCov'): self.descCov=self._service.getDescribeCoverage(self.id) for pos in self.descCov.findall(ns('CoverageOffering/')+ns('domainSet/')+ns('temporalDomain/')+'{http://www.opengis.net/gml}timePosition'): timepositions.append(pos.text) return timepositions timepositions=property(_getTimePositions, None) def _getOtherBoundingBoxes(self): ''' incomplete, should return other bounding boxes not in WGS84 #TODO: find any other bounding boxes. Need to check for gml:EnvelopeWithTimePeriod.''' bboxes=[] if not hasattr(self, 'descCov'): self.descCov=self._service.getDescribeCoverage(self.id) for envelope in self.descCov.findall(ns('CoverageOffering/')+ns('domainSet/')+ns('spatialDomain/')+'{http://www.opengis.net/gml}Envelope'): bbox = {} bbox['nativeSrs'] = envelope.attrib['srsName'] gmlpositions = envelope.findall('{http://www.opengis.net/gml}pos') lc=gmlpositions[0].text.split() uc=gmlpositions[1].text.split() bbox['bbox'] = ( float(lc[0]),float(lc[1]), float(uc[0]), float(uc[1]) ) bboxes.append(bbox) return bboxes boundingboxes=property(_getOtherBoundingBoxes,None) def _getSupportedCRSProperty(self): # gets supported crs info crss=[] for elem in self._service.getDescribeCoverage(self.id).findall(ns('CoverageOffering/')+ns('supportedCRSs/')+ns('responseCRSs')): for crs in elem.text.split(' '): crss.append(Crs(crs)) for elem in self._service.getDescribeCoverage(self.id).findall(ns('CoverageOffering/')+ns('supportedCRSs/')+ns('requestResponseCRSs')): for crs in elem.text.split(' '): crss.append(Crs(crs)) for elem in self._service.getDescribeCoverage(self.id).findall(ns('CoverageOffering/')+ns('supportedCRSs/')+ns('nativeCRSs')): for crs in elem.text.split(' '): crss.append(Crs(crs)) return crss supportedCRS=property(_getSupportedCRSProperty, None) def _getSupportedFormatsProperty(self): # gets supported formats info frmts =[] for elem in self._service.getDescribeCoverage(self.id).findall(ns('CoverageOffering/')+ns('supportedFormats/')+ns('formats')): frmts.append(elem.text) return frmts supportedFormats=property(_getSupportedFormatsProperty, None) def _getAxisDescriptionsProperty(self): #gets any axis descriptions contained in the rangeset (requires a DescribeCoverage call to server). axisDescs =[] for elem in self._service.getDescribeCoverage(self.id).findall(ns('CoverageOffering/')+ns('rangeSet/')+ns('RangeSet/')+ns('axisDescription/')+ns('AxisDescription')): axisDescs.append(AxisDescription(elem)) #create a 'AxisDescription' object. return axisDescs axisDescriptions=property(_getAxisDescriptionsProperty, None) #Adding classes to represent gml:grid and gml:rectifiedgrid. One of these is used for the cvg.grid property #(where cvg is a member of the contents dictionary) #There is no simple way to convert the offset values in a rectifiedgrid grid to real values without CRS understanding, therefore this is beyond the current scope of owslib, so the representation here is purely to provide access to the information in the GML. class Grid(object): ''' Simple grid class to provide axis and value information for a gml grid ''' def __init__(self, grid): self.axislabels = [] self.dimension=None self.lowlimits=[] self.highlimits=[] if grid is not None: self.dimension=int(grid.get('dimension')) self.lowlimits= grid.find('{http://www.opengis.net/gml}limits/{http://www.opengis.net/gml}GridEnvelope/{http://www.opengis.net/gml}low').text.split(' ') self.highlimits = grid.find('{http://www.opengis.net/gml}limits/{http://www.opengis.net/gml}GridEnvelope/{http://www.opengis.net/gml}high').text.split(' ') for axis in grid.findall('{http://www.opengis.net/gml}axisName'): self.axislabels.append(axis.text) class RectifiedGrid(Grid): ''' RectifiedGrid class, extends Grid with additional offset vector information ''' def __init__(self, rectifiedgrid): super(RectifiedGrid,self).__init__(rectifiedgrid) self.origin=rectifiedgrid.find('{http://www.opengis.net/gml}origin/{http://www.opengis.net/gml}pos').text.split() self.offsetvectors=[] for offset in rectifiedgrid.findall('{http://www.opengis.net/gml}offsetVector'): self.offsetvectors.append(offset.text.split()) class AxisDescription(object): ''' Class to represent the AxisDescription element optionally found as part of the RangeSet and used to define ordinates of additional dimensions such as wavelength bands or pressure levels''' def __init__(self, axisdescElem): self.name=self.label=None self.values=[] for elem in axisdescElem.getchildren(): if elem.tag == ns('name'): self.name = elem.text elif elem.tag == ns('label'): self.label = elem.text elif elem.tag == ns('values'): for child in elem.getchildren(): self.values.append(child.text)