How to export a vector layer to a new layer and take extent from canvas?

Question

I want to create a new vector layer based on an existing one and the extent should be based on the current extent of the canvas. How do I do that?

Edit: I am looking for a quick way to do that (a couple of clicks). I don't want to create any additional layers.

So you want to clip the layer to the viewport? – Jake Oct 15 '13 at 17:33 — Jake, Oct 15 '13 at 17:33
Yes, that's what I want to do. – ustroetz Oct 15 '13 at 17:36 — ustroetz, Oct 15 '13 at 17:36

Jake · Accepted Answer · 2013-10-15T19:26:27.903

Running the following code in the QGIS Python console clips all features in the currently active layer with a polygon that exactly covers the current viewport, and adds the clipped features to a memory layer:

viewportPolygon = QgsGeometry().fromWkt(iface.mapCanvas().extent().asWktPolygon())
layer = iface.activeLayer()

resultlayer = QgsVectorLayer("Polygon", "result", "memory")
resultlayer.dataProvider().addAttributes(list(layer.dataProvider().fields()))

clippedFeatures = []
for feature in layer.dataProvider().getFeatures():
    clippedGeometry = feature.geometry().intersection(viewportPolygon)

    if not clippedGeometry.isGeosEmpty():
        feature.setGeometry(clippedGeometry)
        clippedFeatures.append(feature)

resultlayer.dataProvider().addFeatures(clippedFeatures)

QgsMapLayerRegistry.instance().addMapLayer(resultlayer)

score 0 · Answer 2 · answered Oct 15 '13 at 18:02

0

Create a new polygon layer: Layer-> New-> New Shapefile Layer. Draw the new polygon layer over the area of interest, then use the new layer to clip the original vector layer you want cut: Vector-> Geoprocessing Tools-> Clip.

answered Oct 15 '13 at 18:02

Bernie

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There isn't a direct way to do that without creating an extra layer? – ustroetz Oct 15 '13 at 18:04

How to export a vector layer to a new layer and take extent from canvas?

2 Answers2

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