def test_ChangeAttribute(self):
feat = QgsFeature()
feat.addAttribute(1, "text")
feat.changeAttribute(1, "changed")
myChangedAttribute = feat.attributeMap()[1].toString()
myExpectedAttribute = "changed"
myMessage = '\nExpected: %s\nGot: %s' % (myExpectedAttribute,
myChangedAttribute)
assert myChangedAttribute == myExpectedAttribute, myMessage
def test_ChangeAttribute(self):
feat = QgsFeature()
feat.addAttribute(1, "text")
feat.changeAttribute(1, "changed")
myChangedAttribute = feat.attributeMap()[1].toString()
myExpectedAttribute = "changed"
myMessage = '\nExpected: %s\nGot: %s' % (myExpectedAttribute,
myChangedAttribute)
assert myChangedAttribute == myExpectedAttribute, myMessage
def _clip_vector_layer(
layer,
extent,
extra_keywords=None,
explode_flag=True,
hard_clip_flag=False,
explode_attribute=None):
"""Clip a Hazard or Exposure layer to the extents provided.
The layer must be a vector layer or an exception will be thrown.
The output layer will always be in WGS84/Geographic.
:param layer: A valid QGIS vector or raster layer
:type layer:
:param extent: Either 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.
or:
A QgsGeometry of type polygon.
**Polygon clipping is currently only supported for vector datasets.**
:type extent: list(float, float, float, float)
:param extra_keywords: Optional keywords dictionary to be added to
output layer.
:type extra_keywords: dict
:param explode_flag: A bool specifying whether multipart features
should be 'exploded' into singleparts.
**This parameter is ignored for raster layer clipping.**
:type explode_flag: bool
:param hard_clip_flag: A bool specifying whether line and polygon
features that extend beyond the extents should be clipped such that
they are reduced in size to the part of the geometry that intersects
the extent only. Default is False.
**This parameter is ignored for raster layer clipping.**
:type hard_clip_flag: bool
:param explode_attribute: A str specifying to which attribute #1,
#2 and so on will be added in case of explode_flag being true. The
attribute is modified only if there are at least 2 parts.
:type explode_attribute: str
:returns: Clipped layer (placed in the system temp dir). The output layer
will be reprojected to EPSG:4326 if needed.
:rtype: QgsVectorLayer
"""
if not layer or not extent:
myMessage = tr('Layer or Extent passed to clip is None.')
raise InvalidParameterError(myMessage)
if layer.type() != QgsMapLayer.VectorLayer:
myMessage = tr('Expected a vector layer but received a %s.' %
str(layer.type()))
raise InvalidParameterError(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, layer.crs())
myAllowedClipTypes = [QGis.WKBPolygon, QGis.WKBPolygon25D]
if type(extent) is list:
myRect = QgsRectangle(
extent[0], extent[1],
extent[2], extent[3])
# noinspection PyCallByClass
myClipPolygon = QgsGeometry.fromRect(myRect)
elif (type(extent) is QgsGeometry and
extent.wkbType in myAllowedClipTypes):
myRect = extent.boundingBox().toRectF()
myClipPolygon = extent
else:
raise InvalidClipGeometryError(
tr(
'Clip geometry must be an extent or a single part'
'polygon based geometry.'))
myProjectedExtent = myXForm.transformBoundingBox(myRect)
# Get vector layer
myProvider = layer.dataProvider()
if myProvider is None:
myMessage = tr('Could not obtain data provider from '
'layer "%s"' % layer.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,
layer.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(layer.crs(), myGeoCrs)
# Retrieve every feature with its geometry and attributes
myFeature = QgsFeature()
myCount = 0
myHasMultipart = False
if explode_attribute is not None:
theExplodeAttributeIndex = myProvider.fieldNameIndex(
explode_attribute)
while myProvider.nextFeature(myFeature):
myGeometry = myFeature.geometry()
if explode_attribute is not None:
myAttrs = myFeature.attributeMap()
# Loop through the parts adding them to the output file
# we write out single part features unless explode_flag is False
if explode_flag:
myGeometryList = explode_multipart_geometry(myGeometry)
else:
myGeometryList = [myGeometry]
for myPartIndex, myPart in enumerate(myGeometryList):
myPart.transform(myXForm)
if hard_clip_flag:
# Remove any dangling bits so only intersecting area is
# kept.
myPart = clip_geometry(myClipPolygon, myPart)
if myPart is None:
continue
myFeature.setGeometry(myPart)
# There are multiple parts and we want to show it in the
# explode_attribute
if myPartIndex > 0 and explode_attribute is not None:
myHasMultipart = True
myPartAttr = QVariant(
'%s #%s' % (myAttrs[theExplodeAttributeIndex].toString(),
myPartIndex))
myFeature.changeAttribute(theExplodeAttributeIndex, myPartAttr)
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. If hazard and exposure data doesn\'t overlap at all, it '
'is not possible to do an analysis. Another possibility is that '
'the layers do overlap but because they may have different '
'spatial references, they appear to be disjointed. If this is the '
'case, try to turn on reproject on-the-fly in QGIS.')
raise NoFeaturesInExtentError(myMessage)
myKeywordIO = KeywordIO()
if extra_keywords is None:
extra_keywords = {}
extra_keywords['HAD_MULTIPART_POLY'] = myHasMultipart
myKeywordIO.copy_keywords(
layer, myFilename, extra_keywords=extra_keywords)
myBaseName = '%s clipped' % layer.name()
myLayer = QgsVectorLayer(myFilename, myBaseName, 'ogr')
return myLayer
def _clip_vector_layer(
layer,
extent,
extra_keywords=None,
explode_flag=True,
hard_clip_flag=False,
explode_attribute=None):
"""Clip a Hazard or Exposure layer to the extents provided.
The layer must be a vector layer or an exception will be thrown.
The output layer will always be in WGS84/Geographic.
:param layer: A valid QGIS vector or raster layer
:type layer:
:param extent: Either 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.
or:
A QgsGeometry of type polygon.
**Polygon clipping is currently only supported for vector datasets.**
:type extent: list(float, float, float, float)
:param extra_keywords: Optional keywords dictionary to be added to
output layer.
:type extra_keywords: dict
:param explode_flag: A bool specifying whether multipart features
should be 'exploded' into singleparts.
**This parameter is ignored for raster layer clipping.**
:type explode_flag: bool
:param hard_clip_flag: A bool specifying whether line and polygon
features that extend beyond the extents should be clipped such that
they are reduced in size to the part of the geometry that intersects
the extent only. Default is False.
**This parameter is ignored for raster layer clipping.**
:type hard_clip_flag: bool
:param explode_attribute: A str specifying to which attribute #1,
#2 and so on will be added in case of explode_flag being true. The
attribute is modified only if there are at least 2 parts.
:type explode_attribute: str
:returns: Clipped layer (placed in the system temp dir). The output layer
will be reprojected to EPSG:4326 if needed.
:rtype: QgsVectorLayer
"""
if not layer or not extent:
myMessage = tr('Layer or Extent passed to clip is None.')
raise InvalidParameterError(myMessage)
if layer.type() != QgsMapLayer.VectorLayer:
myMessage = tr('Expected a vector layer but received a %s.' %
str(layer.type()))
raise InvalidParameterError(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, layer.crs())
myAllowedClipTypes = [QGis.WKBPolygon, QGis.WKBPolygon25D]
if type(extent) is list:
myRect = QgsRectangle(
extent[0], extent[1],
extent[2], extent[3])
# noinspection PyCallByClass
myClipPolygon = QgsGeometry.fromRect(myRect)
elif (type(extent) is QgsGeometry and
extent.wkbType in myAllowedClipTypes):
myRect = extent.boundingBox().toRectF()
myClipPolygon = extent
else:
raise InvalidClipGeometryError(
tr(
'Clip geometry must be an extent or a single part'
'polygon based geometry.'))
myProjectedExtent = myXForm.transformBoundingBox(myRect)
# Get vector layer
myProvider = layer.dataProvider()
if myProvider is None:
myMessage = tr('Could not obtain data provider from '
'layer "%s"' % layer.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,
layer.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(layer.crs(), myGeoCrs)
# Retrieve every feature with its geometry and attributes
myFeature = QgsFeature()
myCount = 0
myHasMultipart = False
if explode_attribute is not None:
theExplodeAttributeIndex = myProvider.fieldNameIndex(
explode_attribute)
while myProvider.nextFeature(myFeature):
myGeometry = myFeature.geometry()
if explode_attribute is not None:
myAttrs = myFeature.attributeMap()
# Loop through the parts adding them to the output file
# we write out single part features unless explode_flag is False
if explode_flag:
myGeometryList = explode_multipart_geometry(myGeometry)
else:
myGeometryList = [myGeometry]
for myPartIndex, myPart in enumerate(myGeometryList):
myPart.transform(myXForm)
if hard_clip_flag:
# Remove any dangling bits so only intersecting area is
# kept.
myPart = clip_geometry(myClipPolygon, myPart)
if myPart is None:
continue
myFeature.setGeometry(myPart)
# There are multiple parts and we want to show it in the
# explode_attribute
if myPartIndex > 0 and explode_attribute is not None:
myHasMultipart = True
myPartAttr = QVariant(
'%s #%s' % (myAttrs[theExplodeAttributeIndex].toString(),
myPartIndex))
myFeature.changeAttribute(theExplodeAttributeIndex, myPartAttr)
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. If hazard and exposure data doesn\'t overlap at all, it '
'is not possible to do an analysis. Another possibility is that '
'the layers do overlap but because they may have different '
'spatial references, they appear to be disjointed. If this is the '
'case, try to turn on reproject on-the-fly in QGIS.')
raise NoFeaturesInExtentError(myMessage)
myKeywordIO = KeywordIO()
if extra_keywords is None:
extra_keywords = {}
extra_keywords['HAD_MULTIPART_POLY'] = myHasMultipart
myKeywordIO.copy_keywords(
layer, myFilename, extra_keywords=extra_keywords)
myBaseName = '%s clipped' % layer.name()
myLayer = QgsVectorLayer(myFilename, myBaseName, 'ogr')
return myLayer
