def update(self, feature, fields=None):
"""
Updates a :class:`Feature <geoscript.feature.Feature>` of the layer.
*feature* is the feature to update. *fields* is an optional ``list`` of
field names (as ``str`` objects) to update.
>>> from geoscript import geom
>>> l = Layer()
>>> l.add([geom.Point(0,0)])
>>> f = l.first()
>>> f.geom
POINT (0 0)
>>> f.geom = geom.Point(1,1)
>>> l.update(f)
>>> f = l.first()
>>> f.geom
POINT (1 1)
"""
if self.readonly:
raise Exception('Layer is read-only')
f = Filter("IN ('%s')" % feature.id)
if not fields:
fields = feature.schema.keys()
vals = [feature._feature.getAttribute('%s' % fld) for fld in fields]
self._source.modifyFeatures(fields, vals, f._filter)
def histogram(self, field, nbins=10, low=None, high=None, filter=None):
if low is None or high is None:
minmax = self.extrema(field)
low = minmax[0] if low is None else low
high = minmax[1] if high is None else high
rnge = high - low
dx = rnge / float(nbins)
values = [0] * nbins
# should optimize this, we don't need a filter if a low,high is not
# specified
fil = Filter('%s BETWEEN %s AND %s' % (field, low, high))
# concatenate with one specified
fil += self._filter(filter)
fit = self.layer._source.getFeatures(fil._filter).features()
try:
while fit.hasNext():
f = fit.next()
val = f.getAttribute(field)
values[min(nbins - 1, int(
(val - low) / float(rnge) * nbins))] += 1
finally:
fit.close()
keys = [round(low + x * dx, 2) for x in range(0, nbins + 1)]
return zip([(keys[i - 1], keys[i]) for i in range(1, len(keys))],
values)
def extrema(self, field, low=None, high=None, filter=None):
# build a filter based on specified min/max values
fil = ['%s >= %s' % (field, low)] if low != None else []
fil += ['%s <= %s' % (field, high)] if high != None else []
fil = ' AND '.join(fil)
fil = Filter(fil) if len(fil) > 0 else Filter.PASS
# concatenate with one passed in
fil += self._filter(filter)
q = Query(self.layer.name)
q.setFilter(fil._filter)
min, max = None, None
fit = self.layer._source.getFeatures(q).features()
try:
while fit.hasNext():
f = fit.next()
val = f.getAttribute(field)
min = val if min == None or val < min else min
max = val if max == None or val > max else max
finally:
fit.close()
return (min, max)
def count(self, filter=None):
"""
The number of features in the layer as an ``int``.
*filter* is an optional :class:`Filter <geoscript.filter.Filter>` to constrains the counted set of features.
>>> l = Layer()
>>> l.count()
0
>>> from geoscript import geom
>>> l.add([geom.Point(1,2)])
>>> l.add([geom.Point(3,4)])
>>> l.count()
2
>>> l.count('INTERSECTS(geom,POINT(3 4))')
1
"""
f = Filter(filter) if filter else Filter.PASS
count = self._source.getCount(DefaultQuery(self.name, f._filter))
if count == -1:
count = 0
# calculate manually
for f in self.features(filter):
count += 1
return count
def testFilter(self):
s = (Fill('red') + Stroke('blue')
).where("FOO = 'foo'") + Fill('green').where("BAR = 'bar'")
st = s._style()
rules = st.featureTypeStyles()[0].rules()
assert 2 == len(rules)
rule = rules[0]
assert Filter("FOO = 'foo'") == Filter(rule.getFilter())
syms = rule.symbolizers()
assert 2 == len(syms)
assert isinstance(syms[0], PolygonSymbolizer)
assert isinstance(syms[1], LineSymbolizer)
rule = rules[1]
def cursor(self, filter=None, sort=None, hints=None):
"""
Returns a :class:`Cursor <geoscript.layer.cursor.Cursor>` over the features of the layer.
*filter* is a optional :class:`Filter <geoscript.filter.Filter>` to constrain the features iterated over.
*sort* is an optional tuple or ``list`` of tuples that defined the order in
which features are iterated over. The first value of each tuple is the name
of a field to sort on. The second value is one of the strings 'ASC' or
'DESC', representing ascending and decending sort order respectively.
>>> l = Layer()
>>> from geoscript import geom
>>> l.add([geom.Point(1,2)])
>>> l.add([geom.Point(3,4)])
>>> l.add([geom.Point(5,6)])
>>> l.add([geom.Point(7,8)])
>>> l.add([geom.Point(9,10)])
>>> c = l.cursor()
>>> f = c.next()
>>> f.geom
POINT (1 2)
>>> f = c.next()
>>> f.geom
POINT (3 4)
>>> features = c.read(2)
>>> len(features)
2
>>> features[0].geom
POINT (5 6)
>>> features[1].geom
POINT (7 8)
>>> features = c.read(2)
>>> len(features)
1
>>> features[0].geom
POINT (9 10)
>>> c.close()
"""
f = Filter(filter) if filter else Filter.PASS
q = DefaultQuery(self.name, f._filter)
if sort:
sort = sort if isinstance(sort, list) else [sort]
sortBy = []
ff = _filterFactory
for s in sort:
s = s if isinstance(s, tuple) else [s, 'ASC']
sortBy.append(ff.sort(s[0], SortOrder.valueOf(s[1])))
q.setSortBy(sortBy)
if self.proj:
q.coordinateSystem = self.proj._crs
if hints is not None:
q.setHints(Hints(hints))
fcol = self._source.getFeatures(q)
#r = self._source.dataStore.getFeatureReader(q,Transaction.AUTO_COMMIT)
return Cursor(fcol, self)
def _filter(self, filter):
if filter is None:
return self.filter
if self.filter is None:
return filter
return self.filter + Filter(filter)
def filter(self, fil, name=None):
"""
Filters the layer.
*fil* is the :class:`Filter <geoscript.filter.Filter>` to apply.
*name* is the optional name to assign to the new filtered layer.
This method returns a newly filtered layer. The new layer is create within the containing workspace of the original layer.
>>> from geoscript.feature import Schema
>>> l = Layer(schema=Schema('original', [('name', str)]))
>>> l.add(['foo'])
>>> l.add(['bar'])
>>> l.add(['baz'])
>>>
>>> l2 = l.filter("name = 'foo'", "filtered")
>>> l2.count()
1
>>> l3 = l.filter("name LIKE 'b%'", "filtered2")
>>> l3.count()
2
"""
f = Filter(fil)
name = name or Layer._newname()
fschema = feature.Schema(name, self.schema.fields)
# create the filtered layer
flayer = self.workspace.create(schema=fschema)
q = DefaultQuery(self.name, f._filter)
# loop through features and add to new filtered layer
fit = self._source.getFeatures(q).features()
try:
while fit.hasNext():
f = feature.Feature(schema=fschema, f=fit.next())
flayer.add(f)
finally:
fit.close()
return flayer
def bounds(self, filter=None):
"""
The :class:`Bounds <geoscript.geom.Bounds>` of the layer.
*filter* is an optional :class:`Filter <geoscript.filter.Filter>` to constrains the returned bounds.
>>> l = Layer()
>>> from geoscript import geom
>>> l.add([geom.Point(1.0, 2.0)])
>>> l.add([geom.Point(3.0, 4.0)])
>>> l.bounds()
(1.0, 2.0, 3.0, 4.0, EPSG:4326)
>>> l.bounds('INTERSECTS(geom,POINT(3 4))')
(3.0, 4.0, 3.0, 4.0, EPSG:4326)
"""
f = Filter(filter) if filter else Filter.PASS
q = DefaultQuery(self.name, f._filter)
e = self._source.getBounds(q)
if not e:
# try through feature collection
fc = self._source.getFeatures(q)
e = fc.getBounds()
if e:
if e.crs():
return geom.Bounds(env=e)
else:
return geom.Bounds(env=e, prj=self.proj)
else:
# calculate manually
fit = self._source.getFeatures(q).features()
try:
bounds = geom.Bounds(prj=self.proj)
if fit.hasNext():
bounds.init(fit.next().getBounds())
while fit.hasNext():
bounds.expland(fit.next().getBounds())
return bounds
finally:
fit.close()
def delete(self, filter):
"""
Deletes features from the layer which match the specified constraint.
*filter* is a :class:`Filter <geoscript.filter.Filter>` that specifies which features are to be deleted.
>>> l = Layer()
>>> from geoscript import geom
>>> l.add([geom.Point(1,2)])
>>> l.add([geom.Point(3,4)])
>>> l.count()
2
>>> l.delete('INTERSECTS(geom, POINT(3 4))')
>>> l.count()
1
"""
f = Filter(filter) if filter else Filter.FAIL
self._source.removeFeatures(f._filter)
def cursor(self, filter=None):
"""
Returns a :class:`Cursor <geoscript.layer.cursor.Cursor>` over the features of the layer.
*filter* is a optional :class:`Filter <geoscript.filter.Filter>` to constrain the features iterated over.
>>> l = Layer()
>>> from geoscript import geom
>>> l.add([geom.Point(1,2)])
>>> l.add([geom.Point(3,4)])
>>> l.add([geom.Point(5,6)])
>>> l.add([geom.Point(7,8)])
>>> l.add([geom.Point(9,10)])
>>> c = l.cursor()
>>> f = c.next()
>>> f.geom
POINT (1 2)
>>> f = c.next()
>>> f.geom
POINT (3 4)
>>> features = c.read(2)
>>> len(features)
2
>>> features[0].geom
POINT (5 6)
>>> features[1].geom
POINT (7 8)
>>> features = c.read(2)
>>> len(features)
1
>>> features[0].geom
POINT (9 10)
>>> c.close()
"""
f = Filter(filter) if filter else Filter.PASS
q = DefaultQuery(self.name, f._filter)
if self.proj:
q.coordinateSystem = self.proj._crs
r = self._source.dataStore.getFeatureReader(q, Transaction.AUTO_COMMIT)
return Cursor(r, self)
def bounds(self, filter=None):
"""
The :class:`Bounds <geoscript.geom.Bounds>` of the layer.
*filter* is an optional :class:`Filter <geoscript.filter.Filter>` to constrains the returned bounds.
>>> l = Layer()
>>> from geoscript import geom
>>> l.add([geom.Point(1.0, 2.0)])
>>> l.add([geom.Point(3.0, 4.0)])
>>> l.bounds()
(1.0, 2.0, 3.0, 4.0)
>>> l.bounds('INTERSECTS(geom,POINT(3 4))')
(3.0, 4.0, 3.0, 4.0)
"""
f = Filter(filter) if filter else Filter.PASS
e = self._source.getBounds(DefaultQuery(self.name, f._filter))
if e:
return geom.Bounds(env=e)
def __init__(self, layer, filter=None):
self.layer = layer
self.filter = None if filter is None else Filter(filter)
