def render(qs,options):
kwargs = {}
if options:
if ';' in options:
for item in options.split(';'):
if ':' in item:
k,v = item.split(':')
kwargs[k] = v
width = int(kwargs.get('width',600))
height = int(kwargs.get('height',600))
#field = kwargs.get('field',None)
if hasattr(qs,'_meta'):
# it looks like a model
qs = qs.objects.all()
m = mapnik.Map(width,height)
m.aspect_fix_mode = mapnik.aspect_fix_mode.GROW_CANVAS
adapter = PostgisLayer(qs)
lyr = adapter.to_mapnik()
sty = adapter.get_default_style()
lyr.styles.append('style')
m.append_style('style',sty)
#m.background = mapnik.Color('green')
m.srs = lyr.srs
m.layers.append(lyr)
m.zoom_all()
#print mapnik.save_map_to_string(m)
mod = qs.query.get_meta().module_name
# TODO - need way to properly cache vs. always overwriting...
name = '%s_%s_%s_%s.png' % (mod,width,height,random())
map_graphic = os.path.join(graphics,name)
mapnik.render_to_file(m,str(map_graphic))
url = os.path.join(settings.MEDIA_URL,'mapgraphics',name)
return mark_safe(force_unicode('<img src="%s" />' % smart_str(url)))
def show(self, **kwargs):
timeit = kwargs.get('timeit')
if timeit:
start = time.time()
# todo - we should check for postgis support, and otherwise
# use the MemoryDatasource
lyr_adapter = PostgisLayer(self)
lyr_adapter.show(**kwargs)
if timeit:
elapsed = (time.time() - start) / 60
print 'render time: %s seconds' % elapsed
def draw_map(uids,
user,
width,
height,
autozoom=False,
bbox=None,
show_extent=False,
map_name='default'):
"""Display a map with the study region geometry. """
map = get_object_or_404(MapConfig, mapname=map_name)
if not width:
width = map.default_width
if not height:
height = map.default_height
mapfile = str(map.mapfile.path)
# Create a blank image and map
draw = mapnik.Image(width, height)
m = mapnik.Map(width, height)
# load_map is NOT thread safe (?)
# load_map_from_string appears to work
#mapnik.load_map(m, mapfile)
xmltext = open(mapfile).read()
mapnik.load_map_from_string(m, xmltext)
log.debug("Completed load_map_from_string(), Map object is %r" % m)
# Create the mapnik layers
features = get_features(uids, user)
for model, pks in features:
try:
geomfield = model.mapnik_geomfield()
except AttributeError:
geomfield = 'geometry_final'
if geomfield not in [str(x.name) for x in model._meta.fields]:
continue
if not issubclass(model, FeatureCollection):
try:
style = model.mapnik_style()
except AttributeError:
style = default_style()
style_name = str('%s_style' %
model.model_uid()) # tsk mapnik cant take unicode
m.append_style(style_name, style)
adapter = PostgisLayer(model.objects.filter(pk__in=pks),
field_name=geomfield)
lyr = adapter.to_mapnik()
lyr.styles.append(style_name)
m.layers.append(lyr)
# Grab the bounding coordinates and set them if specified
# first, assume default image extent
x1, y1 = map.default_x1, map.default_y1
x2, y2 = map.default_x2, map.default_y2
if not bbox and autozoom and features and len(features) > 0:
x1, y1, x2, y2 = auto_extent(features, map.default_srid)
if bbox:
try:
x1, y1, x2, y2 = [float(x) for x in bbox.split(',')]
except:
pass
bbox = mapnik.Envelope(mapnik.Coord(x1, y1), mapnik.Coord(x2, y2))
if show_extent and features and len(features) > 0:
# Shows a bounding box for the extent of all specified features
# Useful for overview maps
x1, y1, x2, y2 = auto_extent(features, map.default_srid)
ps = mapnik.PolygonSymbolizer(mapnik.Color('#ffffff'))
ps.fill_opacity = 0.8
ls = mapnik.LineSymbolizer(mapnik.Color('#ff0000'), 2.0)
r = mapnik.Rule()
r.symbols.append(ps)
r.symbols.append(ls)
extent_style = mapnik.Style()
extent_style.rules.append(r)
m.append_style('extent_style', extent_style)
lyr = mapnik.Layer("Features Extent")
bbox_sql = """
(select 1 as id, st_setsrid(st_makebox2d(st_point(%s,%s),st_point(%s,%s)), %s) as geometry_final) as aoi
""" % (x1, y1, x2, y2, map.default_srid)
lyr.datasource = mapnik.PostGIS(
host=connection.settings_dict['HOST'],
user=connection.settings_dict['USER'],
password=connection.settings_dict['PASSWORD'],
dbname=connection.settings_dict['NAME'],
table=bbox_sql,
geometry_field='geometry_final',
estimate_extent='False',
extent='%s,%s,%s,%s' % (x1, y1, x2, y2))
lyr.styles.append('extent_style')
m.layers.append(lyr)
# Render image and send out the response
m.zoom_to_box(bbox)
mapnik.render(m, draw)
img = draw.tostring('png')
# if testing via django unit tests, close out the connection
conn = connection.settings_dict
if conn['NAME'] != settings_dbname:
del m
return img
