def delete(self, feature_id):
"""Remove a feature by its id
:param feature_id: the id of the feature
:type feature_id: int
"""
if libvect.Vect_rewrite_line(self.c_mapinfo, feature_id) == -1:
raise GrassError("C function: Vect_rewrite_line.")
def rewrite(self, line, geo_obj, attrs=None, **kargs):
"""Rewrite a geometry features
"""
if self.table is not None and attrs:
attr = [
line,
]
attr.extend(attrs)
self.table.update(key=line, values=attr)
elif self.table is None and attrs:
print("Table for vector {name} does not exist, attributes not"
" loaded".format(name=self.name))
libvect.Vect_cat_set(geo_obj.c_cats, self.layer, line)
result = libvect.Vect_rewrite_line(self.c_mapinfo, line, geo_obj.gtype,
geo_obj.c_points, geo_obj.c_cats)
if result == -1:
raise GrassError("Not able to write the vector feature.")
# return offset into file where the feature starts
geo_obj.offset = result
def rewrite_obj(self, obj, attrs):
"""Return
"""
self.polygon.open('rw', self.layer, with_z=True)
cat = attrs[0]
if obj.gtype == 1:
vtype = 'points'
elif obj.gtype == 2:
vtype = 'lines'
elif obj.gtype == 3:
vtype = 'boundary'
elif obj.gtype == 4:
vtype = 'centroid'
line = self.polygon.cat(cat, vtype, self.layer)[0]
if self.polygon.table is not None and attrs:
self.polygon.table.update(key=line.cat, values=attrs[1:])
elif self.polygon.table is None and attrs:
print("Table for vector {name} does not exist, attributes not"
" loaded".format(name=self.name))
# libvect.Vect_cat_set(obj.c_cats, self.layer, line.cat)
result = libvect.Vect_rewrite_line(self.polygon.c_mapinfo,
line.id, obj.gtype,
obj.c_points,
line.c_cats)
if result == -1:
raise GrassError("Not able to write the vector feature.")
# return offset into file where the feature starts
obj.offset = result
self.polygon.table.conn.commit()
self.polygon.close()
def rewrite(self, geo_obj, cat, attrs=None, **kargs):
"""Rewrite a geometry features
>>> cols = [(u'cat', 'INTEGER PRIMARY KEY'),
... (u'name', 'TEXT')]
Generate a new vector map
>>> test_vect = VectorTopo('newvect_2')
>>> test_vect.open('w', tab_name='newvect_2', tab_cols=cols,
... overwrite=True)
import a geometry feature ::
>>> from grass.pygrass.vector.geometry import Point
create two points ::
>>> point0 = Point(0, 0)
>>> point1 = Point(1, 1)
>>> point2 = Point(2, 2)
then write the two points on the map, with ::
>>> test_vect.write(point0, cat=1, attrs=('pub',))
>>> test_vect.write(point1, cat=2, attrs=('resturant',))
>>> test_vect.table.conn.commit() # save changes in the DB
>>> test_vect.table_to_dict()
{1: [1, u'pub'], 2: [2, u'resturant']}
>>> test_vect.close()
Now rewrite one point of the vector map: ::
>>> test_vect.open('rw')
>>> test_vect.rewrite(point2, cat=1, attrs=('Irish Pub',))
>>> test_vect.table.conn.commit() # save changes in the DB
>>> test_vect.close()
Check the output:
>>> test_vect.open('r')
>>> test_vect[1] == point2
True
>>> test_vect[1].attrs['name'] == 'Irish Pub'
True
>>> test_vect.close()
>>> test_vect.remove()
"""
if self.table is not None and attrs:
self.table.update(key=cat, values=attrs)
elif self.table is None and attrs:
print("Table for vector {name} does not exist, attributes not"
" loaded".format(name=self.name))
libvect.Vect_cat_set(geo_obj.c_cats, self.layer, cat)
result = libvect.Vect_rewrite_line(self.c_mapinfo,
cat, geo_obj.gtype,
geo_obj.c_points,
geo_obj.c_cats)
if result == -1:
raise GrassError("Not able to write the vector feature.")
# return offset into file where the feature starts
geo_obj.offset = result
def delete(self, feature_id):
if libvect.Vect_rewrite_line(self.c_mapinfo, feature_id) == -1:
raise GrassError("C funtion: Vect_rewrite_line.")
def rewrite(self, geo_obj):
result = libvect.Vect_rewrite_line(self.c_mapinfo, geo_obj.id,
geo_obj.gtype, geo_obj.c_points,
geo_obj.c_cats)
# return offset into file where the feature starts
geo_obj.offset = result
