Inspired by this question & answer<http://gis.stackexchange.com/questions/9261/switch-line-direction-in-qgis> as an example of how "easily" can one make its own solutions when using Open Source, I have tried to create my own code to selectively "explode" multipart features during an editing session.
I have explored the QGIS 1.8 API <http://qgis.org/api/1.8/> for the first time, and came out with this piece of code that seams to do the job: layer = qgis.utils.iface.mapCanvas().currentLayer() remove_list = [] for feature in layer.selectedFeatures(): geom = feature.geometry() # check if feature geometry is multipart if geom.isMultipart(): remove_list.append(feature.id()) new_features = [] temp_feature = QgsFeature(feature) # create a new feature using the geometry of each part for part in geom.asGeometryCollection (): temp_feature.setGeometry(part) new_features.append(QgsFeature(temp_feature)) # add new features to layer layer.addFeatures(new_features, False) # remove the original (multipart) features from layerif len(remove_list) > 0: for id in remove_list: layer.deleteFeature (id) I'm not an experienced programmer, so the code might not be the most efficient one. Next steep will be to make a plugin out of it... Or at least, try to! Alexandre Neto On Thu, Dec 27, 2012 at 12:36 PM, Alexandre Neto <senhor.n...@gmail.com>wrote: > There are several questions and respective answers for how to make a > multipart features Layer into a singlepart features one using QGIS: > > - How to break a single polygon into multiple > polys?<http://gis.stackexchange.com/questions/27825/how-to-break-a-single-polygon-into-multiple-polys> > - How to split non-contiguous feature in > QGIS?<http://gis.stackexchange.com/questions/23377/how-to-split-non-contiguous-feature-in-qgis> > > But all the solutions I saw, creates a entirely new layer and would > transform ALL the multipart geometries into single ones. > > So the questions is, how could one, during an edit session, *selectively* > transform > a multipart feature into a singlepart feature, without the need to create a > new layer? > > I saw a ticket <http://trac.osgeo.org/qgis/ticket/3278> for this but it > seems to have been misunderstood. > > It would be the opposite to the "merge selected features" tool, and > similar to > explode<http://webhelp.esri.com/arcgisdesktop/9.2/index.cfm?TopicName=Merging_and_separating_features> > in > ArcGIS. > > Is there any plugin doing this? How could this be done using the python > console? > > > Alexandre Neto > > > PS: I have posted the same > question<http://gis.stackexchange.com/questions/44799/how-to-transform-a-selected-multipart-feature-into-singlepart-features-during-a>in > gis.stackexchange.com In case anyone wants to answer there. >
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