def getStyleInfo(theLayer): """Get styleinfo associated with a layer. Args: * theLayer - InaSAFE layer (raster or vector) Returns: A list of dictionaries containing styleinfo info for a layer. Raises: * StyleInfoNotFoundException if the style is not found. * InvalidParameterException if the paramers are not correct. """ if not theLayer: raise InvalidParameterException() if not hasattr(theLayer, 'get_style_info'): myMessage = tr('Argument "%s" was not a valid layer instance' % theLayer) raise StyleInfoNotFoundException(myMessage) try: myValue = theLayer.get_style_info() except Exception, e: myMessage = tr('Styleinfo retrieval failed for %s\n %s' % (theLayer.get_filename(), str(e))) raise StyleInfoNotFoundException(myMessage)
def readKeywordsFromLayer(theLayer, keyword): """Get metadata from the keywords file associated with a layer. .. note:: Requires a inasafe layer instance as parameter. .. seealso:: getKeywordFromPath Args: * theLayer - a InaSAFE layer (vector or raster) * keyword - the metadata keyword to retrieve e.g. 'title' Returns: A string containing the retrieved value for the keyword. Raises: KeywordNotFoundException if the keyword is not recognised. """ myValue = None if theLayer is None: raise InvalidParameterException() try: myValue = theLayer.get_keywords(keyword) except Exception, e: myMessage = tr('Keyword retrieval failed for %s (%s) \n %s' % (theLayer.get_filename(), keyword, str(e))) raise KeywordNotFoundException(myMessage)
def readKeywordsFromFile(theLayerPath, theKeyword=None): """Get metadata from the keywords file associated with a local file in the file system. .. note:: Requires a str representing a file path instance as parameter As opposed to readKeywordsFromLayer which takes a inasafe file object as parameter. .. seealso:: readKeywordsFromLayer Args: * theLayerPath - a string representing a path to a layer (e.g. '/tmp/foo.shp', '/tmp/foo.tif') * theKeyword - optional - the metadata keyword to retrieve e.g. 'title' Returns: A string containing the retrieved value for the keyword if the keyword argument is specified, otherwise the complete keywords dictionary is returned. Raises: KeywordNotFoundException if the keyword is not recognised. """ # check the source layer path is valid if not os.path.isfile(theLayerPath): myMessage = tr('Cannot get keywords from a non-existant file.' '%s does not exist.' % theLayerPath) raise InvalidParameterException(myMessage) # check there really is a keywords file for this layer myKeywordFilePath = os.path.splitext(theLayerPath)[0] myKeywordFilePath += '.keywords' if not os.path.isfile(myKeywordFilePath): myMessage = tr('No keywords file found for %s' % theLayerPath) raise InvalidParameterException(myMessage) #now get the requested keyword using the inasafe library myDictionary = None try: myDictionary = read_keywords(myKeywordFilePath) except Exception, e: myMessage = tr('Keyword retrieval failed for %s (%s) \n %s' % (myKeywordFilePath, theKeyword, str(e))) raise KeywordNotFoundException(myMessage)
def _clipRasterLayer(theLayer, theExtent, theCellSize=None, theExtraKeywords=None): """Clip a Hazard or Exposure raster layer to the extents provided. The layer must be a raster layer or an exception will be thrown. .. note:: The extent *must* be in EPSG:4326. The output layer will always be in WGS84/Geographic. Args: * theLayer - a valid QGIS raster layer in EPSG:4326 * theExtent - an array representing the exposure layer extents in the form [xmin, ymin, xmax, ymax]. It is assumed that the coordinates are in EPSG:4326 although currently no checks are made to enforce this. * theCellSize - cell size (in GeoCRS) which the layer should be resampled to. If not provided for a raster layer (i.e. theCellSize=None), the native raster cell size will be used. Returns: Path to the output clipped layer (placed in the system temp dir). Raises: Exception if input layer is a density layer in projected coordinates - see issue #123 """ if not theLayer or not theExtent: myMessage = tr('Layer or Extent passed to clip is None.') raise InvalidParameterException(myMessage) if theLayer.type() != QgsMapLayer.RasterLayer: myMessage = tr('Expected a raster layer but received a %s.' % str(theLayer.type())) raise InvalidParameterException(myMessage) myWorkingLayer = str(theLayer.source()) # Check for existence of keywords file myKeywordsPath = myWorkingLayer[:-4] + '.keywords' myMessage = tr('Input file to be clipped "%s" does not have the ' 'expected keywords file %s' % (myWorkingLayer, myKeywordsPath)) verify(os.path.isfile(myKeywordsPath), myMessage) # Raise exception if layer is projected and refers to density (issue #123) # FIXME (Ole): Need to deal with it - e.g. by automatically reprojecting # the layer at this point and setting the native resolution accordingly # in its keywords. myKeywords = readKeywordsFromFile(myKeywordsPath) if 'datatype' in myKeywords and myKeywords['datatype'] == 'density': if theLayer.srs().epsg() != 4326: # This layer is not WGS84 geographic myMessage = ('Layer %s represents density but has spatial ' 'reference "%s". Density layers must be given in ' 'WGS84 geographic coordinates, so please reproject ' 'and try again. For more information, see issue ' 'https://github.com/AIFDR/inasafe/issues/123' % (myWorkingLayer, theLayer.srs().toProj4())) raise InvalidProjectionException(myMessage) # We need to provide gdalwarp with a dataset for the clip # because unline gdal_translate, it does not take projwin. myClipKml = extentToKml(theExtent) # Create a filename for the clipped, resampled and reprojected layer myHandle, myFilename = tempfile.mkstemp('.tif', 'clip_', temp_dir()) os.close(myHandle) os.remove(myFilename) # If no cell size is specified, we need to run gdalwarp without # specifying the output pixel size to ensure the raster dims # remain consistent. if theCellSize is None: myCommand = ('gdalwarp -q -t_srs EPSG:4326 -r near ' '-cutline %s -crop_to_cutline -of GTiff ' '"%s" "%s"' % (myClipKml, myWorkingLayer, myFilename)) else: myCommand = ( 'gdalwarp -q -t_srs EPSG:4326 -r near -tr %f %f ' '-cutline %s -crop_to_cutline -of GTiff ' '"%s" "%s"' % (theCellSize, theCellSize, myClipKml, myWorkingLayer, myFilename)) myExecutablePrefix = '' if sys.platform == 'darwin': # Mac OS X # .. todo:: FIXME - softcode gdal version in this path myExecutablePrefix = ('/Library/Frameworks/GDAL.framework/' 'Versions/1.9/Programs/') myCommand = myExecutablePrefix + myCommand LOGGER.debug(myCommand) myResult = QProcess().execute(myCommand) # For QProcess exit codes see # http://qt-project.org/doc/qt-4.8/qprocess.html#execute if myResult == -2: # cannot be started myMessageDetail = tr('Process could not be started.') myMessage = tr('<p>Error while executing the following shell command:' '</p><pre>%s</pre><p>Error message: %s' % (myCommand, myMessageDetail)) raise CallGDALError(myMessage) elif myResult == -1: # process crashed myMessageDetail = tr('Process could not be started.') myMessage = tr('<p>Error while executing the following shell command:' '</p><pre>%s</pre><p>Error message: %s' % (myCommand, myMessageDetail)) raise CallGDALError(myMessage) # .. todo:: Check the result of the shell call is ok myKeywordIO = KeywordIO() myKeywordIO.copyKeywords(theLayer, myFilename, theExtraKeywords=theExtraKeywords) return myFilename # Filename of created file
def _clipVectorLayer(theLayer, theExtent, theExtraKeywords=None, explodeMultipart=True): """Clip a Hazard or Exposure layer to the extents of the current view frame. The layer must be a vector layer or an exception will be thrown. The output layer will always be in WGS84/Geographic. Args: * theLayer - a valid QGIS vector layer in EPSG:4326 * theExtent - an array representing the exposure layer extents in the form [xmin, ymin, xmax, ymax]. It is assumed that the coordinates are in EPSG:4326 although currently no checks are made to enforce this. * theExtraKeywords - any additional keywords over and above the original keywords that should be associated with the cliplayer. * explodeMultipart - a bool describing if to convert multipart features into singleparts Returns: Path to the output clipped layer (placed in the system temp dir). Raises: None """ if not theLayer or not theExtent: myMessage = tr('Layer or Extent passed to clip is None.') raise InvalidParameterException(myMessage) if theLayer.type() != QgsMapLayer.VectorLayer: myMessage = tr('Expected a vector layer but received a %s.' % str(theLayer.type())) raise InvalidParameterException(myMessage) #myHandle, myFilename = tempfile.mkstemp('.sqlite', 'clip_', # temp_dir()) myHandle, myFilename = tempfile.mkstemp('.shp', 'clip_', temp_dir()) # Ensure the file is deleted before we try to write to it # fixes windows specific issue where you get a message like this # ERROR 1: c:\temp\inasafe\clip_jpxjnt.shp is not a directory. # This is because mkstemp creates the file handle and leaves # the file open. os.close(myHandle) os.remove(myFilename) # Get the clip extents in the layer's native CRS myGeoCrs = QgsCoordinateReferenceSystem() myGeoCrs.createFromId(4326, QgsCoordinateReferenceSystem.EpsgCrsId) myXForm = QgsCoordinateTransform(myGeoCrs, theLayer.crs()) myRect = QgsRectangle(theExtent[0], theExtent[1], theExtent[2], theExtent[3]) myProjectedExtent = myXForm.transformBoundingBox(myRect) # Get vector layer myProvider = theLayer.dataProvider() if myProvider is None: myMessage = tr('Could not obtain data provider from ' 'layer "%s"' % theLayer.source()) raise Exception(myMessage) # Get the layer field list, select by our extent then write to disk # .. todo:: FIXME - for different geometry types we should implement # different clipping behaviour e.g. reject polygons that # intersect the edge of the bbox. Tim myAttributes = myProvider.attributeIndexes() myFetchGeometryFlag = True myUseIntersectFlag = True myProvider.select(myAttributes, myProjectedExtent, myFetchGeometryFlag, myUseIntersectFlag) myFieldList = myProvider.fields() myWriter = QgsVectorFileWriter( myFilename, 'UTF-8', myFieldList, theLayer.wkbType(), myGeoCrs, #'SQLite') # FIXME (Ole): This works but is far too slow 'ESRI Shapefile') if myWriter.hasError() != QgsVectorFileWriter.NoError: myMessage = tr('Error when creating shapefile: <br>Filename:' '%s<br>Error: %s' % (myFilename, myWriter.hasError())) raise Exception(myMessage) # Reverse the coordinate xform now so that we can convert # geometries from layer crs to geocrs. myXForm = QgsCoordinateTransform(theLayer.crs(), myGeoCrs) # Retrieve every feature with its geometry and attributes myFeature = QgsFeature() myCount = 0 while myProvider.nextFeature(myFeature): myGeometry = myFeature.geometry() # Loop through the parts adding them to the output file # we write out single part features unless explodeMultipart is False if explodeMultipart: myGeometryList = explodeMultiPartGeometry(myGeometry) else: myGeometryList = [myGeometry] for myPart in myGeometryList: myPart.transform(myXForm) myFeature.setGeometry(myPart) myWriter.addFeature(myFeature) myCount += 1 del myWriter # Flush to disk if myCount < 1: myMessage = tr('No features fall within the clip extents. ' 'Try panning / zooming to an area containing data ' 'and then try to run your analysis again.') raise NoFeaturesInExtentException(myMessage) myKeywordIO = KeywordIO() myKeywordIO.copyKeywords(theLayer, myFilename, theExtraKeywords=theExtraKeywords) return myFilename # Filename of created file