def _check_str_table(self):
"""
Checks whether a table explicitly named 'social_tenure_relationship'
exists in th database.
:return: True if the table exists.Otherwise False.
:rtype: bool
"""
return pg_table_exists("social_tenure_relationship", False)
def data_source_exists(self, data_source):
"""
:param data_source: Data source object containing table/view name and
corresponding columns.
:type data_source: ComposerDataSource
:return: Checks if the table or view specified in the data source exists.
:rtype: str
"""
return pg_table_exists(data_source.name())
def draw_spatial_unit(self, model, clear_existing=True):
"""
Draw geometry of the given model in the respective local and web views.
:param model: Source model whose geometry will be drawn.
:type model: object
:param clear_existing: Clears any existing features prior to adding the
new features.
:type clear_existing: bool
"""
if model is None:
msg = QApplication.translate("SpatialPreview",
"Data model is empty, the spatial "
"unit cannot be rendered.")
QMessageBox.critical(self, QApplication.translate("SpatialPreview",
"Spatial Unit Preview"),
msg)
return
table_name = model.__class__.__name__.replace(' ', '_').lower()
if not pg_table_exists(table_name):
msg = QApplication.translate("SpatialPreview",
"The spatial unit data source could "
"not be retrieved, the feature cannot "
"be rendered.")
QMessageBox.critical(self, QApplication.translate("SpatialPreview",
"Spatial Unit Preview"),
msg)
return
spatial_cols = table_column_names(table_name, True)
geom, geom_col = None, ""
for sc in spatial_cols:
geom = getattr(model, sc)
#Use the first non-empty geometry value in the collection
if not geom is None:
geom_col = sc
if geom is None:
msg = QApplication.translate("SpatialPreview",
"The selected spatial unit does not "
"contain a valid geometry.")
QMessageBox.critical(self, QApplication.translate("SpatialPreview",
"Spatial Unit Preview"),
msg)
return
geom_type, epsg_code = geometryType(table_name, geom_col)
if self._overlay_layer is None:
self._create_vector_layer(geom_type, epsg_code)
#Add layer to map
QgsMapLayerRegistry.instance().addMapLayer(self._overlay_layer,
False)
#Ensure it is always added on top
QgsProject.instance().layerTreeRoot().insertLayer(0, self._overlay_layer)
if clear_existing:
self.delete_local_features()
feat, extent = self._add_geom_to_map(geom)
#Add spatial unit to web viewer
self._web_spatial_loader.add_overlay(model, geom_col)
#Increase bounding box by 50%, so that layer slightly zoomed out
extent.scale(1.5)
#Select feature. Hack for forcing a selection by using inversion
self._overlay_layer.invertSelection()
self._iface.mapCanvas().setExtent(extent)
self._iface.mapCanvas().refresh()
self.refresh_canvas_layers()
#Need to force event so that layer is shown
QCoreApplication.sendEvent(self.local_map, QShowEvent())