Python QgsJSONExporter.exportFeature方法代码示例

# 需要导入模块: from qgis.core import QgsJSONExporter [as 别名]
# 或者: from qgis.core.QgsJSONExporter import exportFeature [as 别名]
    def testExportFeatureCrs(self):
        """ Test CRS transform when exporting features """

        exporter = QgsJSONExporter()
        self.assertFalse(exporter.sourceCrs().isValid())

        #test layer
        layer = QgsVectorLayer("Point?crs=epsg:3111&field=fldtxt:string",
                               "parent", "memory")
        exporter = QgsJSONExporter(layer)
        self.assertTrue(exporter.sourceCrs().isValid())
        self.assertEqual(exporter.sourceCrs().authid(), 'EPSG:3111')

        exporter.setSourceCrs(QgsCoordinateReferenceSystem(3857, QgsCoordinateReferenceSystem.EpsgCrsId))
        self.assertTrue(exporter.sourceCrs().isValid())
        self.assertEqual(exporter.sourceCrs().authid(), 'EPSG:3857')

        # vector layer CRS should override
        exporter.setVectorLayer(layer)
        self.assertEqual(exporter.sourceCrs().authid(), 'EPSG:3111')

        # test that exported feature is reprojected
        feature = QgsFeature(layer.fields(), 5)
        feature.setGeometry(QgsGeometry(QgsPointV2(2502577, 2403869)))
        feature.setAttributes(['test point'])

        # low precision, only need rough coordinate to check and don't want to deal with rounding errors
        exporter.setPrecision(1)
        expected = """{
   "type":"Feature",
   "id":5,
   "geometry":
   {"type": "Point", "coordinates": [145, -37.9]},
   "properties":{
      "fldtxt":"test point"
   }
}"""
        self.assertEqual(exporter.exportFeature(feature), expected)

# 需要导入模块: from qgis.core import QgsJSONExporter [as 别名]
# 或者: from qgis.core.QgsJSONExporter import exportFeature [as 别名]
    def testExportFeatureRelations(self):
        """ Test exporting a feature with relations """

        #parent layer
        parent = QgsVectorLayer("Point?field=fldtxt:string&field=fldint:integer&field=foreignkey:integer",
                                "parent", "memory")
        pr = parent.dataProvider()
        pf1 = QgsFeature()
        pf1.setFields(parent.fields())
        pf1.setAttributes(["test1", 67, 123])
        pf2 = QgsFeature()
        pf2.setFields(parent.fields())
        pf2.setAttributes(["test2", 68, 124])
        assert pr.addFeatures([pf1, pf2])

        #child layer
        child = QgsVectorLayer(
            "Point?field=x:string&field=y:integer&field=z:integer",
            "referencedlayer", "memory")
        pr = child.dataProvider()
        f1 = QgsFeature()
        f1.setFields(child.fields())
        f1.setAttributes(["foo", 123, 321])
        f2 = QgsFeature()
        f2.setFields(child.fields())
        f2.setAttributes(["bar", 123, 654])
        f3 = QgsFeature()
        f3.setFields(child.fields())
        f3.setAttributes(["foobar", 124, 554])
        assert pr.addFeatures([f1, f2, f3])

        QgsProject.instance().addMapLayers([child, parent])

        rel = QgsRelation()
        rel.setRelationId('rel1')
        rel.setRelationName('relation one')
        rel.setReferencingLayer(child.id())
        rel.setReferencedLayer(parent.id())
        rel.addFieldPair('y', 'foreignkey')

        QgsProject.instance().relationManager().addRelation(rel)

        exporter = QgsJSONExporter()

        exporter.setVectorLayer(parent)
        self.assertEqual(exporter.vectorLayer(), parent)
        exporter.setIncludeRelated(True)
        self.assertEqual(exporter.includeRelated(), True)

        expected = """{
   "type":"Feature",
   "id":0,
   "geometry":null,
   "properties":{
      "fldtxt":"test1",
      "fldint":67,
      "foreignkey":123,
      "relation one":[{"x":"foo",
"y":123,
"z":321},
{"x":"bar",
"y":123,
"z":654}]
   }
}"""
        self.assertEqual(exporter.exportFeature(pf1), expected)

        expected = """{
   "type":"Feature",
   "id":0,
   "geometry":null,
   "properties":{
      "fldtxt":"test2",
      "fldint":68,
      "foreignkey":124,
      "relation one":[{"x":"foobar",
"y":124,
"z":554}]
   }
}"""
        self.assertEqual(exporter.exportFeature(pf2), expected)

        # test excluding related attributes
        exporter.setIncludeRelated(False)
        self.assertEqual(exporter.includeRelated(), False)

        expected = """{
   "type":"Feature",
   "id":0,
   "geometry":null,
   "properties":{
      "fldtxt":"test2",
      "fldint":68,
      "foreignkey":124
   }
}"""
        self.assertEqual(exporter.exportFeature(pf2), expected)

        # test without vector layer set
        exporter.setIncludeRelated(True)
#.........这里部分代码省略.........

# 需要导入模块: from qgis.core import QgsJSONExporter [as 别名]
# 或者: from qgis.core.QgsJSONExporter import exportFeature [as 别名]
    def testJSONExporter(self):
        """ test converting features to GeoJSON """
        fields = QgsFields()
        fields.append(QgsField("name", QVariant.String))
        fields.append(QgsField("cost", QVariant.Double))
        fields.append(QgsField("population", QVariant.Int))

        feature = QgsFeature(fields, 5)
        feature.setGeometry(QgsGeometry(QgsPointV2(5, 6)))
        feature.setAttributes(['Valsier Peninsula', 6.8, 198])

        exporter = QgsJSONExporter()

        expected = """{
   "type":"Feature",
   "id":5,
   "geometry":
   {"type": "Point", "coordinates": [5, 6]},
   "properties":{
      "name":"Valsier Peninsula",
      "cost":6.8,
      "population":198
   }
}"""
        self.assertEqual(exporter.exportFeature(feature), expected)

        # test with linestring for bbox inclusion
        l = QgsLineString()
        l.setPoints([QgsPointV2(5, 6), QgsPointV2(15, 16)])
        feature.setGeometry(QgsGeometry(QgsLineString(l)))

        expected = """{
   "type":"Feature",
   "id":5,
   "bbox":[5, 6, 15, 16],
   "geometry":
   {"type": "LineString", "coordinates": [ [5, 6], [15, 16]]},
   "properties":{
      "name":"Valsier Peninsula",
      "cost":6.8,
      "population":198
   }
}"""
        self.assertEqual(exporter.exportFeature(feature), expected)

        # test that precision is respected
        feature.setGeometry(QgsGeometry(QgsPointV2(5.444444444, 6.333333333)))
        exporter.setPrecision(3)
        self.assertEqual(exporter.precision(), 3)
        expected = """{
   "type":"Feature",
   "id":5,
   "geometry":
   {"type": "Point", "coordinates": [5.444, 6.333]},
   "properties":{
      "name":"Valsier Peninsula",
      "cost":6.8,
      "population":198
   }
}"""
        self.assertEqual(exporter.exportFeature(feature), expected)
        feature.setGeometry(QgsGeometry(QgsPointV2(5, 6)))
        exporter.setPrecision(17)

        # test that attribute subset is respected
        exporter.setAttributes([0, 2])
        self.assertEqual(exporter.attributes(), [0, 2])
        expected = """{
   "type":"Feature",
   "id":5,
   "geometry":
   {"type": "Point", "coordinates": [5, 6]},
   "properties":{
      "name":"Valsier Peninsula",
      "population":198
   }
}"""
        self.assertEqual(exporter.exportFeature(feature), expected)

        exporter.setAttributes([1])
        self.assertEqual(exporter.attributes(), [1])
        expected = """{
   "type":"Feature",
   "id":5,
   "geometry":
   {"type": "Point", "coordinates": [5, 6]},
   "properties":{
      "cost":6.8
   }
}"""
        self.assertEqual(exporter.exportFeature(feature), expected)
        exporter.setAttributes([])

        # text excluding attributes

        exporter.setExcludedAttributes([1])
        self.assertEqual(exporter.excludedAttributes(), [1])
        expected = """{
   "type":"Feature",
   "id":5,
#.........这里部分代码省略.........